Insects

15 pages, 1825 KiB

Open AccessArticle

Individual and Additive Effects of Insecticide and Mating Disruption in Integrated Management of Navel Orangeworm in Almonds

by Bradley S. Higbee and Charles S. Burks

Insects 2021, 12(2), 188; https://doi.org/10.3390/insects12020188 - 22 Feb 2021

Cited by 4 | Viewed by 3708

Abstract

Damage from Amyelois transitella, a key pest of almonds in California, is managed by destruction of overwintering hosts, timely harvest, and insecticides. Mating disruption has been an increasingly frequent addition to these management tools. Efficacy of mating disruption for control of navel [...] Read more.

Damage from Amyelois transitella, a key pest of almonds in California, is managed by destruction of overwintering hosts, timely harvest, and insecticides. Mating disruption has been an increasingly frequent addition to these management tools. Efficacy of mating disruption for control of navel orangeworm damage has been demonstrated in experiments that included control plots not treated with either mating disruption or insecticide. However, the navel orangeworm flies much farther than many orchard pests, so large plots of an expensive crop are required for such research. A large almond orchard was subdivided into replicate blocks of 96 to 224 ha and used to compare harvest damage from navel orangeworm in almonds treated with both mating disruption and insecticide, or with either alone. Regression of navel orangeworm damage in researcher-collected harvest samples from the interior and center of management blocks on damage in huller samples found good correlation for both and supported previous assumptions that huller samples underreport navel orangeworm damage. Blocks treated with both mating disruption and insecticide had lower damage than those treated with either alone in 9 of the 10 years examined. Use of insecticide had a stronger impact than doubling the dispenser rate from 2.5 to 5 per ha, and long-term comparisons of relative navel orangeworm damage to earlier- and later-harvested varieties revealed greater variation than previously demonstrated. These findings are an economically important confirmation of trade-offs in economic management of this critical pest. Additional monitoring tools and research tactics will be necessary to fulfill the potential of mating disruption to reduce insecticide use for navel orangeworm. Full article

(This article belongs to the Special Issue From Insect Pheromones to Mating Disruption: Theory and Practice)

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24 pages, 2836 KiB

Open AccessReview

Toxicity of Insecticides and Miticides to Natural Enemies in Australian Grains: A Review

by Kathy Overton, Ary A. Hoffmann, Olivia L. Reynolds and Paul A. Umina

Insects 2021, 12(2), 187; https://doi.org/10.3390/insects12020187 - 22 Feb 2021

Cited by 17 | Viewed by 3845

Abstract

Continued prophylactic chemical control to reduce pest populations in Australian grain farming systems has limited the effectiveness of biological control via natural enemies in crops within an integrated pest management (IPM) framework. While a variety of data is available to infer potential non-target [...] Read more.

Continued prophylactic chemical control to reduce pest populations in Australian grain farming systems has limited the effectiveness of biological control via natural enemies in crops within an integrated pest management (IPM) framework. While a variety of data is available to infer potential non-target effects of chemicals on arthropod natural enemies, much of it may be irrelevant or difficult to access. Here, we synthesise the literature relevant to Australian grain crops and highlight current knowledge gaps for potential future investment. A range of testing methodologies have been utilised, often deviating from standardised International Organization for Biological Control (IOBC) protocols. Consistent with findings from over 30 years ago, research has continued to occur predominantly at laboratory scales and on natural enemy families that are easily reared or commercially available. There is a paucity of data for many generalist predators, in particular for spiders, hoverflies, and rove and carabid beetles. Furthermore, very few studies have tested the effects of seed treatments on natural enemies, presenting a significant gap given the widespread global use of neonicotinoid seed treatments. There is a need to validate results obtained under laboratory conditions at industry-relevant scales and also prioritise testing on several key natural enemy species we have identified, which should assist with the adoption of IPM practices and decrease the reliance on broad-spectrum chemicals. Full article

(This article belongs to the Special Issue Efficacy of Household and Agricultural Insecticides)

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17 pages, 2087 KiB

Open AccessReview

Filtering the Junk: Assigning Function to the Mosquito Non-Coding Genome

by Elise J. Farley, Heather Eggleston and Michelle M. Riehle

Insects 2021, 12(2), 186; https://doi.org/10.3390/insects12020186 - 22 Feb 2021

Cited by 6 | Viewed by 3289

Abstract

The portion of the mosquito genome that does not code for proteins contains regulatory elements that likely underlie variation for important phenotypes including resistance and susceptibility to infection with arboviruses and Apicomplexan parasites. Filtering the non-coding genome to uncover these functional elements is [...] Read more.

The portion of the mosquito genome that does not code for proteins contains regulatory elements that likely underlie variation for important phenotypes including resistance and susceptibility to infection with arboviruses and Apicomplexan parasites. Filtering the non-coding genome to uncover these functional elements is an expanding area of research, though identification of non-coding regulatory elements is challenging due to the lack of an amino acid-like code for the non-coding genome and a lack of sequence conservation across species. This review focuses on three types of non-coding regulatory elements: (1) microRNAs (miRNAs), (2) long non-coding RNAs (lncRNAs), and (3) enhancers, and summarizes current advances in technical and analytical approaches for measurement of each of these elements on a genome-wide scale. The review also summarizes and highlights novel findings following application of these techniques in mosquito-borne disease research. Looking beyond the protein-coding genome is essential for understanding the complexities that underlie differential gene expression in response to arboviral or parasite infection in mosquito disease vectors. A comprehensive understanding of the regulation of gene and protein expression will inform transgenic and other vector control methods rooted in naturally segregating genetic variation. Full article

(This article belongs to the Collection Genomics and Cytogenetics of Mosquitoes)

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Graphical abstract

15 pages, 4310 KiB

Open AccessArticle

Unraveling the Morphological Variation of Triatoma infestans in the Peridomestic Habitats of Chuquisaca Bolivia: A Geometric Morphometric Approach

by Carolina Vilaseca, Marco A. Méndez, Carlos F. Pinto, Darija Lemic and Hugo A. Benítez

Insects 2021, 12(2), 185; https://doi.org/10.3390/insects12020185 - 22 Feb 2021

Cited by 7 | Viewed by 2998

Abstract

Morphometrics has been used on Triatomines, a well-known phenotypically variable insect, to understand the process of morphological plasticity and infer the changes of this phenomenon. The following research was carried out in two regions of the inter-Andean valleys and two Chaco regions of [...] Read more.

Morphometrics has been used on Triatomines, a well-known phenotypically variable insect, to understand the process of morphological plasticity and infer the changes of this phenomenon. The following research was carried out in two regions of the inter-Andean valleys and two Chaco regions of Chuquisaca-Bolivia. Triatoma infestans adults were collected from the peridomestic (pens and chicken coops) along a geographic gradient in order to evaluate the morphological differentiation between groups and their pattern of sexual shape dimorphism. Geometric morphometric methods were applied on the wings and heads of T. infestans. The main findings include that we proved sexual dimorphism in heads and wings, determined the impact of environmental factors on size and shape and validated the impact of nutrition on head shape variation. These results show that geometric morphometric procedures can be used to provide key insight into the biological adaptation of T. infestans on different biotic (nutrition) and abiotic (environment) conditions, which could serve in understanding and evaluating infestation processes and further vector control programs. Full article

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12 pages, 1519 KiB

Open AccessArticle

Behavioral Responses of the Common Bed Bug to Essential Oil Constituents

by María A. González-Morales, Martín Terán and Alvaro Romero

Insects 2021, 12(2), 184; https://doi.org/10.3390/insects12020184 - 21 Feb 2021

Cited by 15 | Viewed by 4727

Abstract

Botanical-derived pesticides have arisen as an attractive alternative to synthetic insecticides to effectively manage infestations of bed bugs (Cimex lectularius L.). While information on contact, residual, and fumigant toxicity of plant-essential oils against bed bugs have been recently published, there is a [...] Read more.

Botanical-derived pesticides have arisen as an attractive alternative to synthetic insecticides to effectively manage infestations of bed bugs (Cimex lectularius L.). While information on contact, residual, and fumigant toxicity of plant-essential oils against bed bugs have been recently published, there is a gap of information regarding the repellent activity of these products and their constituents. Identification of essential oil constituents (EOCs) with repellent activity will help develop potentially efficacious essential oil-based formulations for use in bed bug management programs. In this study, we first screened fresh and 24 h-aged residues of geraniol, eugenol, carvacrol, thymol, citronellic acid, linalool, menthone, trans-cinnamaldehyde, α-pinene, β-pinene, and limonene for avoidance behavior from individual bed bugs with a video-tracking system. Six EOCs, geraniol, eugenol, citronellic acid, thymol, carvacrol, and linalool were further evaluated overnight in choice tests to determine whether 24-h aged residues were still avoided by groups of bed bugs. While bed bugs avoided resting on filter papers treated with 24-h aged residues of geraniol, eugenol, citronellic acid, and carvacrol, bed bugs aggregated in areas treated with linalool-aged residues. Barriers of EOCs did not prevent bed bugs from reaching a warmed blood source and acquiring blood meals. Our results show that novel formulations of natural product insecticides that include geraniol, eugenol, carvacrol, or citronellic acid have potential to repel bed bugs. The presence of host-associated cues might interfere with these responses. Full article

(This article belongs to the Special Issue Biology and Management of Bed Bugs)

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16 pages, 2020 KiB

Open AccessEditor’s ChoiceArticle

The Eco-Bio-Social Factors That Modulate Aedes aegypti Abundance in South Texas Border Communities

by Jose G. Juarez, Selene M. Garcia-Luna, Matthew C. I. Medeiros, Katherine L. Dickinson, Monica K. Borucki, Matthias Frank, Ismael Badillo-Vargas, Luis F. Chaves and Gabriel L. Hamer

Insects 2021, 12(2), 183; https://doi.org/10.3390/insects12020183 - 21 Feb 2021

Cited by 9 | Viewed by 3737

Abstract

Aedes aegypti control requires dedicated resources that are usually scarce, limiting the reach and sustainability of vector control programs. This generates a need to focus on areas at risk of disease transmission and also understand the factors that might modulate local mosquito abundance. [...] Read more.

Aedes aegypti control requires dedicated resources that are usually scarce, limiting the reach and sustainability of vector control programs. This generates a need to focus on areas at risk of disease transmission and also understand the factors that might modulate local mosquito abundance. We evaluated the eco-bio-social factors that modulate indoor and outdoor relative abundance of female Ae. aegypti in communities of South Texas. We conducted housing quality and Knowledge Attitudes and Practices surveys in households that were part of a weekly mosquito surveillance program in November of 2017 and 2018. Our results showed widespread knowledge of mosquitoes and Zika virus by our participants. However, less than 35% considered them as serious problems in this region. The presence of window-mounted air conditioning units increased the risk of female mosquito relative abundance indoors. An increase in outdoor relative abundance was associated with larger properties and a higher number of children between 6 to 17 years of age. Interestingly, we observed that an increasing number of children <5 years of age modulated both indoor and outdoor relative abundance, with a 52% increase indoors and 30% decrease outdoors. The low perception of mosquito and disease risk highlights engagement needs for vector-borne disease prevention in this region. The identified risk factors can help guide public health officials in their efforts to reduce human and vector contact. Full article

(This article belongs to the Special Issue Urban Pests and Vectors: Interdisciplinary Links between Arthropod–Human Systems)

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13 pages, 689 KiB

Open AccessArticle

(Quasi)-Binomial vs. Gaussian Models to Evaluate Thiamethoxam, Pirimiphos-Methyl, Alpha-Cypermethrin and Deltamethrin on Different Types of Storage Bag Materials Against Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae)

by Nikos E. Papanikolaou, Nickolas G. Kavallieratos, Maria C. Boukouvala and Chrisovalantis Malesios

Insects 2021, 12(2), 182; https://doi.org/10.3390/insects12020182 - 21 Feb 2021

Cited by 12 | Viewed by 2516

Abstract

The Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) are worldwide spread and notorious organisms of numerous stored-products. Both species are dangerous for bagged commodities as penetrators and invaders. The aim [...] Read more.

The Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) are worldwide spread and notorious organisms of numerous stored-products. Both species are dangerous for bagged commodities as penetrators and invaders. The aim of the current study was to examine the efficacy of thiamethoxam, pirimiphos-methyl, alpha-cypermethrin, and deltamethrin, against E. kuehniella and T. confusum larvae, on different types of storage bag materials, i.e., woven propylene, biaxially oriented polypropylene and kraft paper through a (quasi)-binomial modeling approach. The type of the tested storage bag material did not affect the mortality rates of both species when treated with the tested insecticides. Thiamethoxam and pirimiphos-methyl showed statistically significant higher mortality rates on E. kuehniella and T. confusum (beta coefficient = 0.141; p-value < 0.05) compared to alpha-cypermethrin and deltamethrin. In addition, T. confusum exhibited significantly higher mortality rate in comparison to E. kuehniella. Our results also showed that the tested doses and surface treatments had a significant effect on the mortality E. kuehniella and T. confusum larvae. Significantly higher mortality rates were recorded when larvae were exposed on bag materials having both surfaces treated or on the single treated surface than when they were exposed on the untreated surface. Our findings can be useful towards an effective management strategy against stored-product insect pests. Full article

(This article belongs to the Collection Stored-Product Pests: Biology, Ecology, Behavior and Integrated Management)

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9 pages, 900 KiB

Open AccessArticle

Vector Transmission of Tomato Yellow Leaf Curl Thailand Virus by the Whitefly Bemisia tabaci: Circulative or Propagative?

by Wei-Hua Li, De-Fen Mou, Chien-Kuei Hsieh, Sung-Hsia Weng, Wen-Shi Tsai and Chi-Wei Tsai

Insects 2021, 12(2), 181; https://doi.org/10.3390/insects12020181 - 20 Feb 2021

Cited by 5 | Viewed by 3814

Abstract

Viruses that cause tomato yellow leaf curl disease are part of a group of viruses of the genus Begomovirus, family Geminiviridae. Tomato-infecting begomoviruses cause epidemics in tomato crops in tropical, subtropical, and Mediterranean climates, and they are exclusively transmitted by Bemisia [...] Read more.

Viruses that cause tomato yellow leaf curl disease are part of a group of viruses of the genus Begomovirus, family Geminiviridae. Tomato-infecting begomoviruses cause epidemics in tomato crops in tropical, subtropical, and Mediterranean climates, and they are exclusively transmitted by Bemisia tabaci in the field. The objective of the present study was to examine the transmission biology of the tomato yellow leaf curl Thailand virus (TYLCTHV) by B. tabaci, including virus-infected tissues, virus translocation, virus replication, and transovarial transmission. The results demonstrated that the virus translocates from the alimentary gut to the salivary glands via the hemolymph, without apparent replication when acquired by B. tabaci. Furthermore, the virus was detected in 10% of the first-generation progeny of viruliferous females, but the progeny was unable to cause the viral infection of host plants. There was no evidence of transovarial transmission of TYLCTHV in B. tabaci. When combined with the current literature, our results suggest that B. tabaci transmits TYLCTHV in a persistent-circulative mode. The present study enhances our understanding of virus–vector interaction and the transmission biology of TYLCTHV in B. tabaci. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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24 pages, 5124 KiB

Open AccessArticle

Unexpected Effects of Local Management and Landscape Composition on Predatory Mites and Their Food Resources in Vineyards

by Stefan Möth, Andreas Walzer, Markus Redl, Božana Petrović, Christoph Hoffmann and Silvia Winter

Insects 2021, 12(2), 180; https://doi.org/10.3390/insects12020180 - 19 Feb 2021

Cited by 26 | Viewed by 3639

Abstract

Viticultural practices and landscape composition are the main drivers influencing biological pest control in vineyards. Predatory mites, mainly phytoseiid (Phytoseiidae) and tydeoid mites (Tydeidae), are important to control phytophagous mites (Tetranychidae and Eriophyidae) on vines. In the absence of arthropod prey, pollen is [...] Read more.

Viticultural practices and landscape composition are the main drivers influencing biological pest control in vineyards. Predatory mites, mainly phytoseiid (Phytoseiidae) and tydeoid mites (Tydeidae), are important to control phytophagous mites (Tetranychidae and Eriophyidae) on vines. In the absence of arthropod prey, pollen is an important food source for predatory mites. In 32 paired vineyards located in Burgenland/Austria, we examined the effect of landscape composition, management type (organic/integrated), pesticide use, and cover crop diversity of the inter-row on the densities of phytoseiid, tydeoid, and phytophagous mites. In addition, we sampled pollen on vine leaves. Typhlodromus pyri Scheuten was the main phytoseiid mite species and Tydeus goetzi Schruft the main tydeoid species. Interestingly, the area-related acute pesticide toxicity loading was higher in organic than in integrated vineyards. The densities of phytoseiid and tydeoid mites was higher in integrated vineyards and in vineyards with spontaneous vegetation. Their population also profited from an increased viticultural area at the landscape scale. Eriophyoid mite densities were extremely low across all vineyards and spider mites were absent. Biological pest control of phytophagous mites benefits from less intensive pesticide use and spontaneous vegetation cover in vineyard inter-rows, which should be considered in agri-environmental schemes. Full article

(This article belongs to the Special Issue Improving Functional Biodiversity in Vineyards)

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15 pages, 5666 KiB

Open AccessArticle

Unraveling the Mode of Action of Cordyceps fumosorosea: Potential Biocontrol Agent against Plutella xylostella (Lepidoptera: Plutellidae)

by Yanyuan Lei, Abid Hussain, Zhaoying Guan, Desen Wang, Waqar Jaleel, Lihua Lyu and Yurong He

Insects 2021, 12(2), 179; https://doi.org/10.3390/insects12020179 - 18 Feb 2021

Cited by 8 | Viewed by 3676

Abstract

The entomopathogenic fungus, Cordyceps fumosorosea is a potential eco-friendly biocontrol agent. The present study revealed the entire course of infection of P. xylostella by C. fumosorosea with particular reference to cuticular penetration. Comparative studies on the infection of Plutella xylostella larvae by two [...] Read more.

The entomopathogenic fungus, Cordyceps fumosorosea is a potential eco-friendly biocontrol agent. The present study revealed the entire course of infection of P. xylostella by C. fumosorosea with particular reference to cuticular penetration. Comparative studies on the infection of Plutella xylostella larvae by two strains of C. fumosorosea with different pathogenicity were carried out using light, scanning, and transmission electron microscopy. We found that C. fumosorosea tended to adhere to the cuticle surfaces containing protrusions. Although conidia of the lower pathogenic strain IFCF-D58 germinated, they failed to penetrate and complete the development cycle. In contrast, the higher pathogenic strain IFCF01 began to germinate within 4 h and attached to the cuticle by a thin mucilaginous matrix within 8 h post-inoculation. After 24 h post-inoculation, germ tubes and penetrating hyphae reached the cuticular epidermis and began to enter the haemocoel. Within 36 h post-inoculation, the hyphal bodies colonized the body cavity. Hyphae penetrated from inside to outside of the body after 48 h and sporulated the cadavers. After 72 h post-inoculation, numerous conidia emerged and the mycelial covered the entire cuticular surface. The two strains showed similarities in terms of conidial size and germination rate. However, IFCF-D58 exhibited significantly fewer appressoria and longer penetrating hyphae compared to the more infective IFCF01 on all surface topographies. The current pathogen invasion sequence of events suggested that the aggressive growth and propagation along with rapid and massive in vivo production of blastospores facilitate the conidia of IFCF01 to quickly overcome the diamondback moth’s defense mechanism. Full article

(This article belongs to the Special Issue Biological Control and Insect Pathology)

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16 pages, 2029 KiB

Open AccessArticle

Molecular Identification and Immunity Functional Characterization of Lmserpin1 in Locusta migratoria manilensis

by Beibei Li, Hongmei Li, Ye Tian, Nazir Ahmed Abro, Xiangqun Nong, Zehua Zhang and Guangjun Wang

Insects 2021, 12(2), 178; https://doi.org/10.3390/insects12020178 - 18 Feb 2021

Cited by 8 | Viewed by 3127

Abstract

Serine protease inhibitors (Serpins) are a broadly distributed superfamily of proteins that exist in organisms with the role of immune responses. Lmserpin1 gene was cloned firstly from Locusta migratoria manilensis and then was detected in all tested stages from eggs to adults and [...] Read more.

Serine protease inhibitors (Serpins) are a broadly distributed superfamily of proteins that exist in organisms with the role of immune responses. Lmserpin1 gene was cloned firstly from Locusta migratoria manilensis and then was detected in all tested stages from eggs to adults and six different tissues through qRT-PCR analysis. The expression was significantly higher in the 3rd instars and within integument. After RNAi treatment, the expression of Lmserpin1 was significantly down-regulated at four different time points. Moreover, it dropped significantly in the fat body and hemolymph at 24 h after treatment. The bioassay results indicated that the mortality of L. migratoria manilensis treated with dsSerpin1 + Metarhizium was significantly higher than the other three treatments. Furthermore, the immune-related genes (PPAE, PPO, and defensin) treated by dsSerpin1 + Metarhizium were significantly down-regulated compared with the Metarhizium treatment, but the activities of phenoloxidase (PO), peroxidase (POD), superoxide dismutase (SOD), glutathione S-transferase (GST), and multifunctional oxidase (MFO) were fluctuating. Our results suggest that Lmserpin1 plays a crucial role in the innate immunity of L. migratoria manilensis. Lmserpin1 probably took part in regulation of melanization and promoted the synthesis of antimicrobial peptides (AMPs). Full article

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16 pages, 2036 KiB

Open AccessArticle

Inhibitory Copulation Effect of Vibrational Rival Female Signals of Three Stink Bug Species as a Tool for Mating Disruption

by Aline Moreira Dias, Miguel Borges, Maria Carolina Blassioli Moraes, Matheus Lorran Figueira Coelho, Andrej Čokl and Raúl Alberto Laumann

Insects 2021, 12(2), 177; https://doi.org/10.3390/insects12020177 - 18 Feb 2021

Cited by 10 | Viewed by 2332

Abstract

Stink bugs are major pests in diverse crops around the world. Pest management strategies based on insect behavioral manipulation could help to develop biorational management strategies of stink bugs. Insect mating disruption using vibratory signals is an approach with high potential for pest [...] Read more.

Stink bugs are major pests in diverse crops around the world. Pest management strategies based on insect behavioral manipulation could help to develop biorational management strategies of stink bugs. Insect mating disruption using vibratory signals is an approach with high potential for pest management. The objective of this work was to investigate the effect of conspecific female rival signals on the mating behavior and copulation of three stink bug species to establish their potential for mating disruption. Previously recorded female rival signals were played back to bean plants where pairs of the Neotropical brown stink bug, Euschistus heros, and two green stink bugs, Chinavia ubica and Chinavia impicticornis were placed. Vibratory communication and mating behavior were recorded for each pair throughout the experimental time (20 min). Female rival signals show a disrupting effect on the reproductive behavior of three conspecific investigated stink bug species. This effect was more clearly expressed in E. heros and C. ubica than in C. impicticornis. The likelihood of copulating in pairs placed on control plants, without rival signals, increased 29.41 times in E. heros, 4.6 times in C. ubica and 1.71 times in C. impicticornis. However, in the last case, the effect of female rivalry signals in copulation was not significant. The effect of mating disruption of female rival signals of the three stink bug species may originate from the observed reduction in specific vibratory communication signals emitted, which influences the duet formation and further development of different phases of mating behavior. Our results suggest that female rival signals have potential for application in manipulation and disruption of mating behavior of stink bugs. Further work needs to focus on the effects of female rival signals used in long duration experiments and also their interactions with chemical communication of stink bugs. Full article

(This article belongs to the Special Issue Behavioral Manipulation for Pest Control)

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14 pages, 2195 KiB

Open AccessArticle

Bacterial Composition and Diversity of the Digestive Tract of Odontomachus monticola Emery and Ectomomyrmex javanus Mayr

by Zhou Zheng, Xin Hu, Yang Xu, Cong Wei and Hong He

Insects 2021, 12(2), 176; https://doi.org/10.3390/insects12020176 - 17 Feb 2021

Cited by 5 | Viewed by 3070

Abstract

Ponerine ants are generalist predators feeding on a variety of small arthropods, annelids, and isopods; however, knowledge of their bacterial communities is rather limited. This study investigated the bacterial composition and diversity in the digestive tract (different gut sections and the infrabuccal pockets [...] Read more.

Ponerine ants are generalist predators feeding on a variety of small arthropods, annelids, and isopods; however, knowledge of their bacterial communities is rather limited. This study investigated the bacterial composition and diversity in the digestive tract (different gut sections and the infrabuccal pockets (IBPs)) of two ponerine ant species (Odontomachus monticola Emery and Ectomomyrmex javanus Mayr) distributed in northwestern China using high-throughput sequencing. We found that several dominant bacteria that exist in other predatory ants were also detected in these two ponerine ant species, including Wolbachia, Mesoplasma, and Spiroplasma. Bacterial communities of these two ant species were differed significantly from each other, and significant differences were also observed across their colonies, showing distinctive inter-colony characteristics. Moreover, bacterial communities between the gut sections (crops, midguts, and hindguts) of workers were highly similar within colony, but they were clearly different from those in IBPs. Further, bacterial communities in the larvae of O. monticola were similar to those in the IBPs of workers, but significantly different from those in gut sections. We presume that the bacterial composition and diversity in ponerine ants are related to their social behavior and feeding habits, and bacterial communities in the IBPs may play a potential role in their social life. Full article

(This article belongs to the Section Insect Behavior and Pathology)

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8 pages, 646 KiB

Open AccessCommunication

Effects of Rearing Density on Developmental Traits of Two Different Biotypes of the Gypsy Moth, Lymantria Dispar L., from China and the USA

by Yiming Wang, Robert L. Harrison and Juan Shi

Insects 2021, 12(2), 175; https://doi.org/10.3390/insects12020175 - 17 Feb 2021

Cited by 3 | Viewed by 2710

Abstract

The life-history traits of the gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae), have been observed to vary with larval population density, which can increase significantly during an outbreak of this pest. Laboratory studies on density-dependent variation in gypsy moth development have focused on [...] Read more.

The life-history traits of the gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae), have been observed to vary with larval population density, which can increase significantly during an outbreak of this pest. Laboratory studies on density-dependent variation in gypsy moth development have focused on single populations and were limited to comparing solitary larvae with groups of larvae reared at a single density. To evaluate how density-dependent impacts on development vary with different populations and subspecies of L. dispar, we compared the effects of rearing larvae of a European gypsy moth (L. dispar dispar L.) population from Connecticut, USA; and larvae of two populations of the Asian gypsy moth (L. dispar asiatica Vnukovskij) from Guizhou and Hebei provinces in China. Larvae were reared on an artificial diet at densities of one, three, five, seven, and nine larvae per 115 mL container, and the duration of larval development, percentage of surviving larvae, and the rates of pupation and emergence were measured at each density. A two-tailed response to density variation with values falling away on both sides from a peak or climbing from a base was observed for all three populations tested, with the most rapid larval development and the highest values of survival, pupation, and emergence observed at a density of five larvae/container. Although differences in larval development time, survival, pupation and emergence were observed among the different populations under the conditions of our study, our findings indicate that density-dependent effects on the development of different gypsy moth subspecies and populations follow the same trends. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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13 pages, 1152 KiB

Open AccessFeature PaperReview

The Relationship between Research and Casework in Forensic Entomology

by Martin J. R. Hall

Insects 2021, 12(2), 174; https://doi.org/10.3390/insects12020174 - 17 Feb 2021

Cited by 16 | Viewed by 7112

Abstract

Research is a vital component of all forensic sciences and is often stimulated by casework, which identifies gaps in our knowledge. In such a niche area of forensic science as entomology there should be a close and mutually beneficial relationship between research and [...] Read more.

Research is a vital component of all forensic sciences and is often stimulated by casework, which identifies gaps in our knowledge. In such a niche area of forensic science as entomology there should be a close and mutually beneficial relationship between research and casework: to some extent there is a continuum between the two and many forensic entomologists are involved in both to a greater or lesser degree. However, research and casework involve quite differing challenges, from the replicated, highly controlled, sometimes esoteric aspects of research to the very individual, sometimes chaotic and disruptive, but highly applied aspects of casework. Ideally casework will include the full involvement of a forensic entomologist, who will collect the insect and climate evidence at the scene and produce a robust expert witness statement based on a full analysis of this data. Unfortunately, it can also include situations where samples, if collected at all, are poorly preserved, not representative of the full cadaver fauna available and presented to the entomologist months or years after the event, without local temperature data. While research is recognised through publications and their citation indices, casework and its associated expert witness statements often receive no credit in an academic workplace, although they do have a positive societal impact and many other benefits of teaching and public engagement value. This manuscript examines the relationship between research and casework from a UK perspective, to raise awareness of the need to create an environment that values the contribution of both, for future generations to flourish in both areas. Full article

(This article belongs to the Special Issue From Laboratory Studies to Court Evidence: Challenges in Forensic Entomology)

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17 pages, 2767 KiB

Open AccessArticle

Aphid Assemblages Associated with Urban Park Plant Communities

by Tadeusz Barczak, Janina Bennewicz, Maciej Korczyński, Małgorzata Błażejewicz-Zawadzińska and Hanna Piekarska-Boniecka

Insects 2021, 12(2), 173; https://doi.org/10.3390/insects12020173 - 17 Feb 2021

Cited by 5 | Viewed by 2803

Abstract

Some aphid species are important agricultural pests, sometimes also found on plants growing in urban areas. In this work, we set out to identify the plant species, communities or habitats that are more attractive to aphids in order to limit their spread into [...] Read more.

Some aphid species are important agricultural pests, sometimes also found on plants growing in urban areas. In this work, we set out to identify the plant species, communities or habitats that are more attractive to aphids in order to limit their spread into new green areas. The aim of the study was to determine and compare plant communities and the assemblages of aphids associated with them in different urban park habitats. The research hypothesis assumed that the differences between aphid assemblages depend on plant diversity and hence reflect urban park habitat environmental conditions, in particular the plant communities and the floral structure. The study was carried out in Bydgoszcz (northern Poland), and four parks were taken into consideration. Herein, floristic lists were used to calculate ecological indicator values for each park. The aphid species richness was determined, as well as the relative abundance and dominance structure similarities of the aphid assemblages. Our results demonstrated that Prunus spp. were strongly infested by Hyalopterus pruni, similarly as Philadelphus inodorus by Aphis fabae, Sambucus nigra by Aphis sambuci, and Acerplatanoides and A. pseudoplatanus by Periphyllus testudinaceus. Park plantations of Robinia pseudoacacia were not very attractive to aphids. The most attractive plant communities to aphids were syntaxonomically identifiable as alluvial alder forests in the layer of trees and Cornus sanguinea in the layer of shrubs. Full article

(This article belongs to the Section Insect Ecology, Diversity and Conservation)

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18 pages, 7003 KiB

Open AccessReview

Cultural Control of Drosophila suzukii in Small Fruit—Current and Pending Tactics in the U.S.

by Torsten Schöneberg, Margaret T. Lewis, Hannah J. Burrack, Matthew Grieshop, Rufus Isaacs, Dalila Rendon, Mary Rogers, Nikki Rothwell, Ashfaq A. Sial, Vaughn M. Walton and Kelly A. Hamby

Insects 2021, 12(2), 172; https://doi.org/10.3390/insects12020172 - 17 Feb 2021

Cited by 30 | Viewed by 7434

Abstract

Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), a vinegar fly of Asian origin, has emerged as a devastating pest of small and stone fruits throughout the United States. Tolerance for larvae is extremely low in fresh market fruit, and management is primarily achieved [...] Read more.

Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), a vinegar fly of Asian origin, has emerged as a devastating pest of small and stone fruits throughout the United States. Tolerance for larvae is extremely low in fresh market fruit, and management is primarily achieved through repeated applications of broad-spectrum insecticides. These applications are neither economically nor environmentally sustainable, and can limit markets due to insecticide residue restrictions, cause outbreaks of secondary pests, and select for insecticide resistance. Sustainable integrated pest management programs include cultural control tactics and various nonchemical approaches for reducing pest populations that may be useful for managing D. suzukii. This review describes the current state of knowledge and implementation for different cultural controls including preventative tactics such as crop selection and exclusion as well as strategies to reduce habitat favorability (pruning; mulching; irrigation), alter resource availability (harvest frequency; sanitation), and lower suitability of fruit postharvest (cooling; irradiation). Because climate, horticultural practices, crop, and market underlie the efficacy, feasibility, and affordability of cultural control tactics, the potential of these tactics for D. suzukii management is discussed across different production systems. Full article

(This article belongs to the Special Issue Organic Pest Management of Invertebrate Pests: A Frontier Borne of Constraints?)

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20 pages, 611 KiB

Open AccessEditor’s ChoiceReview

Western Corn Rootworm, Plant and Microbe Interactions: A Review and Prospects for New Management Tools

by Kyle J. Paddock, Christelle A. M. Robert, Matthias Erb and Bruce E. Hibbard

Insects 2021, 12(2), 171; https://doi.org/10.3390/insects12020171 - 17 Feb 2021

Cited by 20 | Viewed by 5048

Abstract

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is resistant to four separate classes of traditional insecticides, all Bacillius thuringiensis (Bt) toxins currently registered for commercial use, crop rotation, innate plant resistance factors, and even double-stranded RNA (dsRNA) targeting essential genes via environmental [...] Read more.

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is resistant to four separate classes of traditional insecticides, all Bacillius thuringiensis (Bt) toxins currently registered for commercial use, crop rotation, innate plant resistance factors, and even double-stranded RNA (dsRNA) targeting essential genes via environmental RNA interference (RNAi), which has not been sold commercially to date. Clearly, additional tools are needed as management options. In this review, we discuss the state-of-the-art knowledge about biotic factors influencing herbivore success, including host location and recognition, plant defensive traits, plant-microbe interactions, and herbivore-pathogens/predator interactions. We then translate this knowledge into potential new management tools and improved biological control. Full article

(This article belongs to the Special Issue Corn Rootworm: Biology, Ecology, Behavior and Integrated Management)

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15 pages, 8855 KiB

Open AccessArticle

Comparative Mitogenomic Analysis of Heptageniid Mayflies (Insecta: Ephemeroptera): Conserved Intergenic Spacer and tRNA Gene Duplication

by Ran Li, Zhiming Lei, Wenjuan Li, Wei Zhang and Changfa Zhou

Insects 2021, 12(2), 170; https://doi.org/10.3390/insects12020170 - 16 Feb 2021

Cited by 15 | Viewed by 2801

Abstract

Large intergenic spacers and tRNA gene duplications have been reported in several insect groups, although little is known about mitogenomes of mayflies. Here, we determined complete mitogenomes of ten heptageniid species and systemically analyzed their mitogenomic features. Both a conserved intergenic spacer (IGS) [...] Read more.

Large intergenic spacers and tRNA gene duplications have been reported in several insect groups, although little is known about mitogenomes of mayflies. Here, we determined complete mitogenomes of ten heptageniid species and systemically analyzed their mitogenomic features. Both a conserved intergenic spacer (IGS) and trnM duplication were detected in those mitogenomes. The IGS, which was observed in heptageniids, could be further folded into a stable stem–loop structure. The tRNA gene duplication was found in almost all analyzed mitogenomes, and a unique gene block trnI-trnM-trnQ-trnM-ND2 was also discovered. Our analysis demonstrates that the heptageniid gene arrangement pattern can be explained by the tandem duplication-random loss (TDRL) model. Phylogenetic analyses using both Bayesian inference (BI) and maximum likelihood (ML) methods based on the nucleotide and amino acid sequence data recovered the genus Epeorus as monophyletic with strong support. Our results provide a better understanding of mitogenomic evolution in Heptageniidae, as well as novel molecular markers for species identification of mayflies. Full article

(This article belongs to the Section Insect Molecular Biology and Genomics)

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12 pages, 921 KiB

Open AccessReview

Models Applied to Grapevine Pests: A Review

by Federico Lessio and Alberto Alma

Insects 2021, 12(2), 169; https://doi.org/10.3390/insects12020169 - 16 Feb 2021

Cited by 17 | Viewed by 4256

Abstract

This paper reviews the existing predictive models concerning insects and mites harmful to grapevine. A brief conceptual description is given on the definition of a model and about different types of models: deterministic vs. stochastics, continuous vs. discrete, analytical vs. computer-based, and descriptive [...] Read more.

This paper reviews the existing predictive models concerning insects and mites harmful to grapevine. A brief conceptual description is given on the definition of a model and about different types of models: deterministic vs. stochastics, continuous vs. discrete, analytical vs. computer-based, and descriptive vs. data-driven. The main biological aspects of grapevine pests covered by different types of models are phenology, population growth and dynamics, species distribution, and invasion risk. A particular emphasis is put on forecasting epidemics of plant disease agents transmitted by insects with sucking-piercing mouthparts. The most investigated species or groups are the glassy-winged sharpshooter Homalodisca vitripennis (Germar) and other vectors of Xylella fastidiosa subsp. fastidiosa, a bacterium agent of Pierce’s disease; the European grape berry moth, Lobesia botrana (Denis and Schiffermuller); and the leafhopper Scaphoideus titanus Ball, the main vector of phytoplasmas agents of Flavescence dorée. Finally, the present and future of decision-support systems (DSS) in viticulture is discussed. Full article

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13 pages, 1571 KiB

Open AccessArticle

The Modeling and Forecasting of Carabid Beetle Distribution in Northwestern China

by Xueqin Liu, Hui Wang, Dahan He, Xinpu Wang and Ming Bai

Insects 2021, 12(2), 168; https://doi.org/10.3390/insects12020168 - 16 Feb 2021

Cited by 11 | Viewed by 2637

Abstract

Beetles are key insect species in global biodiversity and play a significant role in steppe ecosystems. In the temperate steppe of China, the increasing degeneration of the grasslands threatens beetle species and their habitat. Using Generalized Additive Models (GAMs), we aimed to predict [...] Read more.

Beetles are key insect species in global biodiversity and play a significant role in steppe ecosystems. In the temperate steppe of China, the increasing degeneration of the grasslands threatens beetle species and their habitat. Using Generalized Additive Models (GAMs), we aimed to predict and map beetle richness patterns within the temperate steppe of Ningxia (China). We tested 19 environmental predictors including climate, topography, soil moisture and space as well as vegetation. Climatic variables (temperature, precipitation, soil temperature) consistently appeared among the most important predictors for beetle groups modeled. GAM generated predictive cartography for the study area. Our models explained a significant percentage of the variation in carabid beetle richness (79.8%), carabid beetle richness distribution seems to be mainly influenced by temperature and precipitation. The results have important implications for management and conservation strategies and also provides evidence for assessing and making predictions of beetle diversity across the steppe. Full article

(This article belongs to the Section Insect Ecology, Diversity and Conservation)

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18 pages, 1293 KiB

Open AccessArticle

A Linkage-Based Genome Assembly for the Mosquito Aedes albopictus and Identification of Chromosomal Regions Affecting Diapause

by John H. Boyle, Pasi M. A. Rastas, Xin Huang, Austin G. Garner, Indra Vythilingam and Peter A. Armbruster

Insects 2021, 12(2), 167; https://doi.org/10.3390/insects12020167 - 16 Feb 2021

Cited by 16 | Viewed by 3343

Abstract

The Asian tiger mosquito, Aedes albopictus, is an invasive vector mosquito of substantial public health concern. The large genome size (~1.19–1.28 Gb by cytofluorometric estimates), comprised of ~68% repetitive DNA sequences, has made it difficult to produce a high-quality genome assembly for [...] Read more.

The Asian tiger mosquito, Aedes albopictus, is an invasive vector mosquito of substantial public health concern. The large genome size (~1.19–1.28 Gb by cytofluorometric estimates), comprised of ~68% repetitive DNA sequences, has made it difficult to produce a high-quality genome assembly for this species. We constructed a high-density linkage map for Ae. albopictus based on 111,328 informative SNPs obtained by RNAseq. We then performed a linkage-map anchored reassembly of AalbF2, the genome assembly produced by Palatini et al. (2020). Our reassembled genome sequence, AalbF3, represents several improvements relative to AalbF2. First, the size of the AalbF3 assembly is 1.45 Gb, almost half the size of AalbF2. Furthermore, relative to AalbF2, AalbF3 contains a higher proportion of complete and single-copy BUSCO genes (84.3%) and a higher proportion of aligned RNAseq reads that map concordantly to a single location of the genome (46%). We demonstrate the utility of AalbF3 by using it as a reference for a bulk-segregant-based comparative genomics analysis that identifies chromosomal regions with clusters of candidate SNPs putatively associated with photoperiodic diapause, a crucial ecological adaptation underpinning the rapid range expansion and climatic adaptation of A. albopictus. Full article

(This article belongs to the Collection Genomics and Cytogenetics of Mosquitoes)

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10 pages, 1114 KiB

Open AccessArticle

Antennal and Behavioral Responses of Drosophila suzukii to Volatiles from a Non-Crop Host, Osyris wightiana

by Yan Liu, Zhihao Cui, Mi Shi, Marc Kenis, Wenxia Dong, Feng Zhang, Jinping Zhang, Chun Xiao and Li Chen

Insects 2021, 12(2), 166; https://doi.org/10.3390/insects12020166 - 15 Feb 2021

Cited by 8 | Viewed by 2531

Abstract

Drosophila suzukii (Diptera: Drosophilidae) infests a variety of commercial fruits, including cherries and other soft-skinned fruits. After the cropping season of most cultivated crop hosts, it heavily infests the fruit of a wild host-plant, Osyris wightiana in southwest China. Here, we employ gas [...] Read more.

Drosophila suzukii (Diptera: Drosophilidae) infests a variety of commercial fruits, including cherries and other soft-skinned fruits. After the cropping season of most cultivated crop hosts, it heavily infests the fruit of a wild host-plant, Osyris wightiana in southwest China. Here, we employ gas chromatography-electroantennographic detection (GC-EAD) together with behavioral bioassays and a trapping experiment to identify volatile semiochemicals emitted by O. wightiana that are involved in D. suzukii attraction. GC-EAD recordings of D. suzukii antenna showed responses to 13 compounds, including α-pinene, 3-methylbutyl acetate, 2-hexanol, E-β-ocimene, Z-3-hexenol, β-caryophyllene, α-humulene, and six unidentified compounds. The flies were attracted by seven individual EAD-active compounds at low doses (0.01 and 0.1 μg), but were repelled at high doses (10 and 100 μg). In a similar manner, a blend of seven EAD-active compounds at low doses (0.1 and 1 μg) was attractive to female flies, but became repulsive at high doses (10 μg). The low dose of the blend was as attractive as the fruit volatiles, although both were less attractive than the fruits. The blend attracted both female and male D. suzukii and other Drosophila flies. The percentage of D. suzukii out of all flies captured by the blend was significantly greater than that captured by the control. These results indicate that the EAD-active volatile compounds emitted by fruits of O. wightiana play an important role in D. suzukii attraction, and have the potential to be used for management of D. suzukii. Full article

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20 pages, 2885 KiB

Open AccessArticle

Distributional Patterns of Aquatic Empididae (Diptera) along an Elevational Diversity Gradient in a Low Mountain Range: An Example from Central Europe

by Iwona Słowińska and Radomir Jaskuła

Insects 2021, 12(2), 165; https://doi.org/10.3390/insects12020165 - 15 Feb 2021

Cited by 5 | Viewed by 2859

Abstract

The two subfamilies Hemerodromiinae and Clinocerinae, also known as aquatic dance flies, are a group of small predatory insects occurring mainly in mountainous areas and the northern temperate. However, very little is known about distribution patterns for most of the species. Habitat preferences [...] Read more.

The two subfamilies Hemerodromiinae and Clinocerinae, also known as aquatic dance flies, are a group of small predatory insects occurring mainly in mountainous areas and the northern temperate. However, very little is known about distribution patterns for most of the species. Habitat preferences for 40 aquatic empidid species were analysed in the Pieniny Mts., Poland. Forty-six sampling sites from a major part of this relatively low mountain massif (400–770 m) were chosen, for which 17 micro and macrohabitat environmental variables were measured including both abiotic (altitude, stream mean width and depth, and shading) and biotic factors (13 dominant plant communities). Here we show that numerous studied aquatic Empididae were characterized by unique habitat preferences and were restricted to the foothills or the lower montane zone with only a few species characterized by wider elevational distribution. Chelifera pectinicauda, C. flavella, C. subangusta and Phyllodromia melanocephala (Hemerodromiinae), and Clinocera appendiculata, C. fontinalis, C. wesmaeli, Dolichocephala guttata, D. oblongoguttata, Kowarzia plectrum, Wiedemannia jazdzewskii, and W. thienemanni (Clinocerinae) were clearly associated with the highest altitudes and shaded areas while W. bistigma, W. lamellata, W. phantasma, and W. tricuspidata (Clinocerinae) were clearly associated with the lower elevated, wider stream valleys overgrown by willow brakes. Species richness and diversity decreased along elevational gradient with the hump-shaped diversity pattern noted for the subfamily Clinocerinae. The altitude, size of river/stream as well as the type of plant community were found as the most important factors in the distribution of the studied aquatic empidid species. The present study is the first one focused on elevational diversity gradient and habitat preferences of Hemerodromiinae and Clinocerinae of central Europe, and one of only a few in the world. Full article

(This article belongs to the Collection Insects in Mountain Ecosystems)

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12 pages, 3391 KiB

Open AccessArticle

Physical Mapping of the Anopheles (Nyssorhynchus) darlingi Genomic Scaffolds

by Míriam Silva Rafael, Leticia Cegatti Bridi, Igor V. Sharakhov, Osvaldo Marinotti, Maria V. Sharakhova, Vladimir Timoshevskiy, Giselle Moura Guimarães-Marques, Valéria Silva Santos, Carlos Gustavo Nunes da Silva, Spartaco Astolfi-Filho and Wanderli Pedro Tadei

Insects 2021, 12(2), 164; https://doi.org/10.3390/insects12020164 - 15 Feb 2021

Cited by 1 | Viewed by 2764

Abstract

The genome assembly of Anopheles darlingi consists of 2221 scaffolds (N50 = 115,072 bp) and has a size spanning 136.94 Mbp. This assembly represents one of the smallest genomes among Anopheles species. Anopheles darlingi genomic DNA fragments of ~37 Kb were cloned, end-sequenced, [...] Read more.

The genome assembly of Anopheles darlingi consists of 2221 scaffolds (N50 = 115,072 bp) and has a size spanning 136.94 Mbp. This assembly represents one of the smallest genomes among Anopheles species. Anopheles darlingi genomic DNA fragments of ~37 Kb were cloned, end-sequenced, and used as probes for fluorescence in situ hybridization (FISH) with salivary gland polytene chromosomes. In total, we mapped nine DNA probes to scaffolds and autosomal arms. Comparative analysis of the An. darlingi scaffolds with homologous sequences of the Anopheles albimanus and Anopheles gambiae genomes identified chromosomal rearrangements among these species. Our results confirmed that physical mapping is a useful tool for anchoring genome assemblies to mosquito chromosomes. Full article

(This article belongs to the Collection Genomics and Cytogenetics of Mosquitoes)

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18 pages, 15467 KiB

Open AccessArticle

Evaluating the Impact of Post-Emergence Weed Control in Honeybee Colonies Located in Different Agricultural Surroundings

by Ivana N. Macri, Diego E. Vázquez, Eduardo A. Pagano, Jorge A. Zavala and Walter M. Farina

Insects 2021, 12(2), 163; https://doi.org/10.3390/insects12020163 - 14 Feb 2021

Cited by 7 | Viewed by 3835

Abstract

The honeybee Apis mellifera is exposed to agricultural intensification, which leads to an improved reliance upon pesticide use and the reduction of floral diversity. In the present study, we assess the changes in the colony activity and the expression profile of genes involved [...] Read more.

The honeybee Apis mellifera is exposed to agricultural intensification, which leads to an improved reliance upon pesticide use and the reduction of floral diversity. In the present study, we assess the changes in the colony activity and the expression profile of genes involved in xenobiotic detoxification in larvae and adult honeybees from three apiaries located in agricultural environments that differ in their proportion of the crop/wild flora. We evaluated these variables before and after the administration of a mixture of three herbicides during the summer season. The expression of several cytochrome P450 monooxygenases decreased significantly in larvae after post-emergence weed control and showed significant differences between apiaries in the case of honeybee workers. Principal component analysis (PCA) revealed that colonies located in the plot near to a wetland area exhibited a different relative gene expression profile after herbicide application compared with the other plots. Moreover, we found significant positive correlations between pollen collection and the pesticide detoxification genes that discriminated between plots in the PCA. Our results suggest that nutrition may modify herbicide impact on honeybees and that larvae are more harmed than adults in agroecosystems, a factor that will alter the colonies’ population growth at the end of the blooming period. Full article

(This article belongs to the Special Issue Honeybees and Wild Bees Health)

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11 pages, 888 KiB

Open AccessArticle

Evaluation of Eleven Plant Species as Potential Banker Plants to Support Predatory Orius sauteri in Tea Plant Systems

by Ruifang Zhang, Dezhong Ji, Qiuqiu Zhang and Linhong Jin

Insects 2021, 12(2), 162; https://doi.org/10.3390/insects12020162 - 14 Feb 2021

Cited by 10 | Viewed by 2646

Abstract

Tea green leafhoppers and thrips are key pests in tea plantations and have widely invaded those of Asian origin. Pesticides are currently a favorable control method but not desirable for frequent use on tea plants. To meet Integrated Pest Management (IPM) demand, biological [...] Read more.

Tea green leafhoppers and thrips are key pests in tea plantations and have widely invaded those of Asian origin. Pesticides are currently a favorable control method but not desirable for frequent use on tea plants. To meet Integrated Pest Management (IPM) demand, biological control with a natural enemy is viewed as the most promising way. Orius sauteri are slated to be a natural enemy to tea pests. However, more knowledge of rearing O. sauteri and selecting banker plant systems is strongly needed. The reproductive biology evaluation of the egg oviposition and population life parameters of O. sauteri under laboratory conditions were examined, and the supporting ability of 11 plant species—motherwort, white clover, red bean, mung bean, peanut, soybean, kidney bean, herba violae, bush vetch, smooth vetch, and common vetch—in a greenhouse was assessed. Most of the selected plants, except for herba violae, performed relatively well with high oviposition quantity and survival. The mean fecundity per female on red bean and motherwort was 148.75 eggs and 148.25 eggs, respectively, and 90.20 eggs for tea plants (the smallest); there also were significant differences. In an experiment to determine the life parameters of O. sauteri, all the tested plants, except herba violae, were found to be able to complete the growth and development of the life cycle; there also were significant differences. The intrinsic rate of increase of motherwort and red bean was 1.18 and 1.17, respectively, and higher compared to that of the other plants, including tea plants (1.13). This result of the O. sauteri population development index was also confirmed in a greenhouse with the number of motherwort and red beans being as high as 113.33 and 112.67. Since motherwort was found to be susceptible to aphids and powdery mildew in each trial, it cannot be used for intercropping in tea gardens. Among the 11 plants, red bean was found to be the most suitable to support O. sauteri in tea plantations. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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24 pages, 5212 KiB

Open AccessEditor’s ChoiceArticle

Further Insights on the Migration Biology of Monarch Butterflies, Danaus plexippus (Lepidoptera: Nymphalidae) from the Pacific Northwest

by David G. James and Linda Kappen

Insects 2021, 12(2), 161; https://doi.org/10.3390/insects12020161 - 14 Feb 2021

Cited by 13 | Viewed by 5624

Abstract

The fall migration of monarch butterflies, Danaus plexippus (L.), in the Pacific Northwest was studied during 2017–2019 by tagging 14,040 captive-reared and 450 wild monarchs. One hundred and twenty-two captive-reared monarchs (0.87%) were recovered at distances averaging 899.9 ± 98.6 km for Washington-released [...] Read more.

The fall migration of monarch butterflies, Danaus plexippus (L.), in the Pacific Northwest was studied during 2017–2019 by tagging 14,040 captive-reared and 450 wild monarchs. One hundred and twenty-two captive-reared monarchs (0.87%) were recovered at distances averaging 899.9 ± 98.6 km for Washington-released and 630.5 ± 19.9 km for Oregon-released monarchs. The greatest straight-line release to recovery distance was 1392.1 km. A mean travel rate of 20.7 ± 2.2 km/day and maximum travel of 46.1 km/day were recorded. Recovery rates were greater for Oregon-released monarchs (0.92%) than Washington-released (0.34%) or Idaho-released monarchs (0.30%). Most monarchs (106/122) were recovered SSW-S-SSE in California, with 82 at 18 coastal overwintering sites. Two migrants from Oregon were recovered just weeks after release ovipositing in Santa Barbara and Palo Alto, CA. Two migrants released in central Washington recovered up to 360.0 km to the SE, and recoveries from Idaho releases to the S and SE suggests that some Pacific Northwest migrants fly to an alternative overwintering destination. Monarchs released in southern Oregon into smoky, poor quality air appeared to be as successful at reaching overwintering sites and apparently lived just as long as monarchs released into non-smoky, good quality air. Migration and lifespan for monarchs infected with the protozoan parasite, Ophryocystis elektroscirrha (McLaughlin and Myers), appeared to be similar to the migration and survival of uninfected monarchs, although data are limited. Our data improve our understanding of western monarch migration, serving as a basis for further studies and providing information for conservation planning. Full article

(This article belongs to the Collection Butterfly Diversity and Conservation)

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12 pages, 999 KiB

Open AccessArticle

Natural Occurrence of Entomopathogenic Fungi as Endophytes of Sugarcane (Saccharum officinarum) and in Soil of Sugarcane Fields

by Trust Kasambala Donga, Richard Meadow, Nicolai V. Meyling and Ingeborg Klingen

Insects 2021, 12(2), 160; https://doi.org/10.3390/insects12020160 - 13 Feb 2021

Cited by 11 | Viewed by 3732

Abstract

The natural occurrence of entomopathogenic fungal endophytes in sugarcane (Saccharum officinarum) and in soil samples from sugarcane fields was evaluated in Chikwawa District, southern Malawi. Fungi from soil were isolated by baiting using Galleria mellonella larva. Fungal endophytes were isolated from [...] Read more.

The natural occurrence of entomopathogenic fungal endophytes in sugarcane (Saccharum officinarum) and in soil samples from sugarcane fields was evaluated in Chikwawa District, southern Malawi. Fungi from soil were isolated by baiting using Galleria mellonella larva. Fungal endophytes were isolated from surface-sterilized plant tissue sections. Forty-seven isolates resembled the genus Beauveria, 9 isolates were Metarhizium, and 20 isolates were Isaria. There was no significant difference in the number and type of fungal isolates collected from soil and from plant tissue. There was, however, a significant difference in the part of the plant where fungal species were isolated, which fungal species were isolated, and the number of fungal species isolated at each location. Phylogenetic analysis of 47 Beauveria isolates based on DNA sequencing of the Bloc intergenic region indicated that these isolates all belonged to B. bassiana and aligned with sequences of B. bassiana isolates of African and Neotropical origin. The Malawian B. bassiana isolates formed a distinct clade. No larvae died from infestation by multiple fungi. To the best of our knowledge, this is the first report of B. bassiana and Isaria spp. occurring naturally as endophytes in sugarcane. Further, it is the first report of B. bassiana, Isaria spp., and Metarhizium spp. in the soil of sugarcane fields in Africa. Full article

(This article belongs to the Special Issue Plant-Arthropod-Microorganism Interactions)

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18 pages, 1789 KiB

Open AccessArticle

Operational Parameters for the Aerial Release of Sterile Codling Moths Using an Uncrewed Aircraft System

by Evan D. Esch, Rachael M. Horner, Dustin C. Krompetz, Nathan Moses-Gonzales, Melissa R. Tesche and David Maxwell Suckling

Insects 2021, 12(2), 159; https://doi.org/10.3390/insects12020159 - 13 Feb 2021

Cited by 4 | Viewed by 3049

Abstract

The codling moth is a serious pest of apples in most regions of the world where this fruit is produced. The sterile insect technique is one strategy used to control this pest and is employed as part of an area-wide integrated pest management [...] Read more.

The codling moth is a serious pest of apples in most regions of the world where this fruit is produced. The sterile insect technique is one strategy used to control this pest and is employed as part of an area-wide integrated pest management program for the codling moth in British Columbia, Canada. Modified fixed wing aircraft are the most common method for the release of sterile insects in large area-wide pest management programs. However, aerial release with a full-size aircraft can be prohibitively expensive. We evaluated the use of small, uncrewed aircraft systems (UASs) for the release of sterile codling moths. Sterile codling moths released from greater altitudes were more broadly distributed and drifted more in strong winds, compared to those released from lower altitudes. Most of the released insects were recaptured in a 50 m wide swath under the release route. Recapture rates for aerially released insects were 40–70% higher compared to those released from the ground. UASs provide a promising alternative to ground release and conventional aircraft for the release of sterile codling moths. Full article

(This article belongs to the Special Issue Sterile Insect Technique (SIT) and Its Applications)

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