Insects

15 pages, 2201 KiB

Open AccessArticle

Volatiles from Different Instars of Honeybee Worker Larvae and Their Food

by Haohao Zhang, Chunsheng Hou, Pingli Dai, Yongjun Liu, Yanyan Wu, Yonggang Pang and Qingyun Diao

Insects 2019, 10(4), 118; https://doi.org/10.3390/insects10040118 - 25 Apr 2019

Cited by 3 | Viewed by 3061

Abstract

(E)-β-Ocimene was the only volatile chemical found to be emitted by whole, live worker larvae of Apis mellifera L. when sampling in the vapor phase. In addition to (E)-β-ocimene, there is evidence for the existence of other volatiles, but [...] Read more.

(E)-β-Ocimene was the only volatile chemical found to be emitted by whole, live worker larvae of Apis mellifera L. when sampling in the vapor phase. In addition to (E)-β-ocimene, there is evidence for the existence of other volatiles, but the changes in their composition and contents remain unknown during larval development, as are their differences from larvae to larval food. We investigated volatile components of worker larvae and larval food using solid phase dynamic extraction (SPDE) coupled with gas chromatography-mass spectrometry (GC-MS). Nine compounds were identified with certainty and six tentatively, including terpenoids, aldehydes, hydrocarbons, an ester and a ketone. The contents of volatiles in the second-instar worker larvae differ greatly from those in larvae of other stages. This is mainly attributable to terpenoids, which resulted in the second-instar worker larvae having significantly higher amounts of overall volatiles. Larval food contained significantly higher amounts of aldehydes and hydrocarbons than the corresponding larvae from the fourth to fifth-instar. We discovered volatiles in worker larvae and their food that were never reported before; we also determined the content changes of these volatiles during larval development. Full article

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11 pages, 817 KiB

Open AccessCommunication

First Screening of Entomopathogenic Nematodes and Fungus as Biocontrol Agents against an Emerging Pest of Sugarcane, Cacosceles newmannii (Coleoptera: Cerambycidae)

by Marion Javal, John S. Terblanche, Desmond E. Conlong and Antoinette P. Malan

Insects 2019, 10(4), 117; https://doi.org/10.3390/insects10040117 - 25 Apr 2019

Cited by 11 | Viewed by 4041

Abstract

Cacosceles newmannii (Coleoptera: Cerambycidae) is an emerging pest of sugarcane in South Africa. The larvae of this cerambycid beetle live within the sugarcane stalk and drill galleries that considerably reduce sugar production. To provide an alternative to chemical control, entomopathogenic nematodes and fungus [...] Read more.

Cacosceles newmannii (Coleoptera: Cerambycidae) is an emerging pest of sugarcane in South Africa. The larvae of this cerambycid beetle live within the sugarcane stalk and drill galleries that considerably reduce sugar production. To provide an alternative to chemical control, entomopathogenic nematodes and fungus were investigated as potential biological control agents to be used in an integrated pest management system. The nematodes Steinernema yirgalemense, S. jeffreyense, Heterorhabditis indica, and different concentrations of the fungus Metarhizium pinghaense were screened for efficacy (i.e., mortality rate) against larvae of C. newmannii. The different biocontrol agents used, revealed a low level of pathogenicity to C. newmannii larvae, when compared to control treatments. Full article

(This article belongs to the Special Issue Ecology and Pest Management of Sugarcane Insects)

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11 pages, 1914 KiB

Open AccessArticle

Foraging Behavior and Pollination Efficiency of Apis mellifera L. on the Oil Tree Peony ‘Feng Dan’ (Paeonia ostii T. Hong et J.X. Zhang)

by Chunling He, Kaiyue Zhang, Xiaogai Hou, Dongbo Han and Shuaibing Wang

Insects 2019, 10(4), 116; https://doi.org/10.3390/insects10040116 - 25 Apr 2019

Cited by 13 | Viewed by 3735

Abstract

To solve the issue of insufficient pollinating of insects for the oil tree peony ‘Feng Dan’ (Paeonia ostii T. Hong et J.X. Zhang) and improve its seed set and yield, we conducted observations from 2017 to 2018 to investigate the relationship between [...] Read more.

To solve the issue of insufficient pollinating of insects for the oil tree peony ‘Feng Dan’ (Paeonia ostii T. Hong et J.X. Zhang) and improve its seed set and yield, we conducted observations from 2017 to 2018 to investigate the relationship between honey bee (Apis mellifera L.) foraging behavior and diurnal activity. We compared the single-fruit seed set ratio among three flower types on the same plants of the oil tree peony, which flowered simultaneously, in three pollination areas (bee pollination, natural field pollination, and controlled pollination by pollinators) and in a net room under self-pollination, wind pollination and bee pollination. Apis mellifera exhibited short single visitations, long visitations to a single flower and repeated visits to flowers of the oil tree peony. The number of flower visits of A. mellifera was significantly and positively yet weakly correlated with the number of stigma visits (2017: r = 0.045, p < 0.05; 2018: r = 0.195, p < 0.01). The seed set of oil tree peony follicles in the A. mellifera pollination area was significantly higher than that in the natural pollination field area and the control net rooms. On the same oil tree peony plant with synchronous flowering, the percent seed set of follicles pollinated by A. mellifera at a high density was significantly higher than that resulting from wind pollination and self-pollination. Full article

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12 pages, 1788 KiB

Open AccessArticle

The Effects of a Bacterial Endotoxin on Behavior and Sensory-CNS-Motor Circuits in Drosophila melanogaster

by Oscar Istas, Abigail Greenhalgh and Robin Cooper

Insects 2019, 10(4), 115; https://doi.org/10.3390/insects10040115 - 22 Apr 2019

Cited by 11 | Viewed by 3856

Abstract

The effect of bacterial sepsis on animal behavior and physiology is complex due to direct and indirect actions. The most common form of bacterial sepsis in humans is from gram-negative bacterial strains. The endotoxin (lipopolysaccharide, LPS) and/or associated peptidoglycans from the bacteria are [...] Read more.

The effect of bacterial sepsis on animal behavior and physiology is complex due to direct and indirect actions. The most common form of bacterial sepsis in humans is from gram-negative bacterial strains. The endotoxin (lipopolysaccharide, LPS) and/or associated peptidoglycans from the bacteria are the key agents to induce an immune response, which then produces a cascade of immunological consequences. However, there are direct actions of LPS and associated peptidoglycans on cells which are commonly overlooked. This study showed behavioral and neural changes in larval Drosophila fed commercially obtained LPS from Serratia marcescens. Locomotor behavior was not altered, but feeding behavior increased and responses to sensory tactile stimuli were decreased. In driving a sensory-central nervous system (CNS)-motor neural circuit in in-situ preparations, direct application of commercially obtained LPS initially increased evoked activity and then decreased and even stopped evoked responses in a dose-dependent manner. With acute LPS and associated peptidoglycans exposure (10 min), the depressed neural responses recovered within a few minutes after removal of LPS. Commercially obtained LPS induces a transitory hyperpolarization of the body wall muscles within seconds of exposure and alters activity within the CNS circuit. Thus, LPS and/or associated peptidoglycans have direct effects on body wall muscle without a secondary immune response. Full article

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12 pages, 804 KiB

Open AccessArticle

Sensory Quality of Essential Oils and Their Synergistic Effect with Diatomaceous Earth, for the Control of Stored Grain Insects

by Erika Carla Pierattini, Stefano Bedini, Francesca Venturi, Roberta Ascrizzi, Guido Flamini, Rossella Bocchino, Jessica Girardi, Paolo Giannotti, Giuseppe Ferroni and Barbara Conti

Insects 2019, 10(4), 114; https://doi.org/10.3390/insects10040114 - 20 Apr 2019

Cited by 27 | Viewed by 4277

Abstract

Essential oils (EOs) have gained increasing interest as a low-toxic, eco-friendly alternative to synthetic repellents and insecticides against insect pests. However, they have scarce practical application in the protection of stored grain because of their limited efficacy and their interference with the organoleptic [...] Read more.

Essential oils (EOs) have gained increasing interest as a low-toxic, eco-friendly alternative to synthetic repellents and insecticides against insect pests. However, they have scarce practical application in the protection of stored grain because of their limited efficacy and their interference with the organoleptic properties of the grain. In this study, we evaluated the olfactory profile of the EOs of Foeniculum vulgare, Pistacia lentiscus, and Ocimum basilicum, and their toxicity against the main stored grain pest Sitophilus granarius. Trained assessors identified O. basilicum and F. vulgare, as more suitable than the P. lentiscus EO for the wheat treatment. In laboratory tests, the most toxic EO was the P. lentiscus (LC₅₀ = 36.36 μL∙kg⁻¹) while, the least toxic, was the F. vulgare one (LC₅₀ = 77.59 μL∙kg⁻¹). The EOs were also tested combined with diatomaceous earths (DEs) showing synergistic effects (co-toxicity coefficient values ranging from 1.36 to 3.35 for O. basilicum and F. vulgare EOs, respectively). Overall, O. basilicum resulted as the best EO for the wheat treatment, considering its insect toxicity and olfactory profile. In real storage conditions, the wheat co-treated with O. basilicum EO and DEs showed a significantly lower mean infestation (1.5 insect kg⁻¹) than the non-treated wheat (7.0 insect kg⁻¹). Full article

(This article belongs to the Special Issue Improving Stored Product Insect Pest Management)

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13 pages, 1790 KiB

Open AccessArticle

Exploring an Odor-Baited “Trap Bush” Approach to Aggregate Plum Curculio (Coleoptera: Curculionidae) Injury in Blueberries

by Cesar Rodriguez-Saona, Anne Nielsen, David Shapiro-Ilan, Sunil Tewari, Vera Kyryczenko-Roth, Nicolas Firbas and Tracy Leskey

Insects 2019, 10(4), 113; https://doi.org/10.3390/insects10040113 - 19 Apr 2019

Cited by 3 | Viewed by 3232

Abstract

This 2-year study (2013–2014) assessed the efficacy of an odor-baited “trap bush” approach to aggregate plum curculio, Conotrachelus nenuphar, adult injury, i.e., number of oviposition-scared fruit, in four commercial highbush blueberry farms in New Jersey (USA). In each farm, we compared fruit [...] Read more.

This 2-year study (2013–2014) assessed the efficacy of an odor-baited “trap bush” approach to aggregate plum curculio, Conotrachelus nenuphar, adult injury, i.e., number of oviposition-scared fruit, in four commercial highbush blueberry farms in New Jersey (USA). In each farm, we compared fruit injury in bushes baited with grandisoic acid and benzaldehyde along the perimeter of trap-bush plots versus unbaited bushes in control plots. We also measured the amount of fruit injury in neighboring bushes (i.e., spillover effect) and in the plots’ interior. In both years, the amount of fruit injury by C. nenuphar adults was greater on and near odor-baited bushes in trap-bush plots compared with those on and near unbaited bushes in control plots, indicative of aggregation. Injury in unbaited bushes neighboring trap bushes was often greater than unbaited bushes in control plots, providing some evidence for a spillover effect. However, no difference in fruit injury was found between interior trap-bush and control plots. Therefore, odor-baited trap bushes can be used in blueberries to manipulate C. nenuphar foraging behavior, i.e., aggregate adults, without compromising injury in field interiors. Under this approach, insecticides could then be targeted at only a few (perimeter-row) bushes within fields rather than entire fields. Full article

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14 pages, 1508 KiB

Open AccessArticle

Local and Landscape Drivers of Carabid Activity, Species Richness, and Traits in Urban Gardens in Coastal California

by Stacy M. Philpott, Simone Albuquerque, Peter Bichier, Hamutahl Cohen, Monika H. Egerer, Claire Kirk and Kipling W. Will

Insects 2019, 10(4), 112; https://doi.org/10.3390/insects10040112 - 19 Apr 2019

Cited by 27 | Viewed by 4339

Abstract

Urban ecosystems, as mosaics of residential, industrial, commercial, and agricultural land, present challenges for species survival due to impervious surface, degradation, fragmentation, and modification of natural habitat, pollution, and introduced species. Some urban habitats, such as community gardens, support biodiversity and promote ecosystem [...] Read more.

Urban ecosystems, as mosaics of residential, industrial, commercial, and agricultural land, present challenges for species survival due to impervious surface, degradation, fragmentation, and modification of natural habitat, pollution, and introduced species. Some urban habitats, such as community gardens, support biodiversity and promote ecosystem services. In gardens, local factors (e.g., vegetation, groundcover) and landscape surroundings (e.g., agriculture, built or impervious cover) may influence species abundance, richness, and functional traits that are present. We examined which local and landscape factors within 19 community gardens in the California central coast influence ground beetle (Carabidae) activity density, species richness, functional group richness, and functional traits—body size, wing morphology, and dispersal ability. Gardens with higher crop richness and that are surrounded by agricultural land had greater carabid activity density, while species and functional group richness did not respond to any local or landscape factor. Gardens with more leaf litter had lower carabid activity, and gardens with more leaf litter tended to have more larger carabids. Changes in local (floral abundance, ground cover) and landscape (urban land cover) factors also influenced the distribution of individuals with certain wing morphology and body size traits. Thus, both local and landscape factors influence the taxonomic and functional traits of carabid communities, with potential implications for pest control services that are provided by carabids. Full article

(This article belongs to the Special Issue Urban Small Farms and Gardens Pest Management)

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12 pages, 1723 KiB

Open AccessArticle

Exposure to Insecticides Reduces Populations of Rhynchophorus palmarum in Oil Palm Plantations with Bud Rot Disease

by Luis Carlos Martínez, Angelica Plata-Rueda, Francisco Andrés Rodríguez-Dimaté, Juliana Mendonça Campos, Valdeir Celestino dos Santos Júnior, Gabriela Da Silva Rolim, Flavio Lemes Fernandes, Wiane Meloni Silva, Carlos Frederico Wilcken, José Cola Zanuncio and José Eduardo Serrão

Insects 2019, 10(4), 111; https://doi.org/10.3390/insects10040111 - 19 Apr 2019

Cited by 21 | Viewed by 3751

Abstract

The South American palm weevil (SAPW), Rhynchophorus palmarum Linnaeus (Coleoptera: Curculionidae) is the main pest of Elaeis guineensis and damages palm trees with bud rot disease in the Americas. The effects of six neurotoxic insecticides (abamectin, carbaryl, deltamethrin, fipronil, imidacloprid and spinosad) were [...] Read more.

The South American palm weevil (SAPW), Rhynchophorus palmarum Linnaeus (Coleoptera: Curculionidae) is the main pest of Elaeis guineensis and damages palm trees with bud rot disease in the Americas. The effects of six neurotoxic insecticides (abamectin, carbaryl, deltamethrin, fipronil, imidacloprid and spinosad) were evaluated against SAPW for toxicity, survival, reproduction, and mortality. Abamectin (LC₅₀ = 0.33 mg mL⁻¹), Carbaryl (LC₅₀ = 0.24 mg mL⁻¹), deltamethrin (LC₅₀ = 0.17 mg mL⁻¹), and fipronil (LC₅₀ = 0.42 mg mL⁻¹) were the most toxic to SAPW. Adult survival was 95% without exposure to insecticides, decreasing to 78–65% in insects treated with the LC₂₅ and 49–35% in insects exposed to LC₅₀. Sublethal doses of carbaryl, fipronil and imidacloprid showed significant effect on the reproduction of this insect. Mortality of SAPW populations caused by insecticides had similar effects in the laboratory and field conditions. The results suggest that carbaryl, deltamethrin, fipronil, and imidacloprid caused significantly higher mortality as compared to the control in SAPW and may be used to control its populations in oil palm trees where bud rot appears as the key disease for SAPW attraction and infestation. Full article

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9 pages, 360 KiB

Open AccessCommunication

Endophytic Effects of Beauveria bassiana on Corn (Zea mays) and Its Herbivore, Rachiplusia nu (Lepidoptera: Noctuidae)

by María Leticia Russo, Ana Clara Scorsetti, María Florencia Vianna, Marta Cabello, Natalia Ferreri and Sebastian Pelizza

Insects 2019, 10(4), 110; https://doi.org/10.3390/insects10040110 - 18 Apr 2019

Cited by 55 | Viewed by 4747

Abstract

Entomopathogenic fungi are widely recognized as agents of biological control worldwide. Their use in agriculture for the regulation of pest populations is a promising alternative to conventional insecticides. Furthermore, recent studies have shown that entomopathogenic fungi fulfill an additional role in plants as [...] Read more.

Entomopathogenic fungi are widely recognized as agents of biological control worldwide. Their use in agriculture for the regulation of pest populations is a promising alternative to conventional insecticides. Furthermore, recent studies have shown that entomopathogenic fungi fulfill an additional role in plants as growth promoters. The purpose of this investigation was to assess the growth and yield of corn plants colonized with Beauveria bassiana and its effect on the lepidopteran pest Rachiplusia nu. Effects of the fungus on plant growth, crop yield, and vertical transmission were evaluated in the field. Feeding preferences of R. nu larvae were assessed in the laboratory using a “choice test”. Corn plants inoculated with B. bassiana showed an increase in height, number of leaves, grain weight, yield, and percentage of seed germination compared to control plants. Consumption of B. bassiana-colonized corn plants by R. nu larvae was reduced compared to feeding levels observed on non-inoculated plants. This study showed that endophytic B. bassiana can provide multiple benefits to Zea mays and can play an important role in future integrated pest management programs. Full article

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12 pages, 582 KiB

Open AccessArticle

Hymenoptera Complex Associated with Myzus persicae and Hyalopterus spp. in Peach Orchards in Northeastern Spain and Prospects for Biological Control of Aphids

by Yahana Aparicio, Rosa Gabarra, Jordi Riudavets, Petr Starý, Željko Tomanović, Korana Kocić, Juli Pujade Villar, Mar Ferrer Suay, Victor Cuesta Porta and Judit Arnó

Insects 2019, 10(4), 109; https://doi.org/10.3390/insects10040109 - 16 Apr 2019

Cited by 8 | Viewed by 3229

Abstract

Aphids are a serious pest for peach crops. They have traditionally been managed with insecticides, but there is increasing concern about the risk that insecticides pose to both humans and the environment. As a first step to use biological control in aphid management, [...] Read more.

Aphids are a serious pest for peach crops. They have traditionally been managed with insecticides, but there is increasing concern about the risk that insecticides pose to both humans and the environment. As a first step to use biological control in aphid management, we conducted a 3-year field survey in northeastern Spain to determine which parasitoids and hyperparasitoids were most prevalent on two aphids, Myzus persicae (Sulzer) and Hyalopterus spp. Koch, the most harmful to peach trees. We collected 11 parasitoid species from M. persicae, with Aphidius matricariae (Haliday) being the most abundant. Two parasitoid species were also collected from Hyalopterus spp., Aphidius transcaspicus Telenga and Praon volucre (Haliday). Hyperparasitoid species overlapped between these aphids but their relative abundances differed. We also discuss the possible impacts of hyperparasitoids on parasitoid populations. Our results suggest that it would be feasible to implement biocontrol methods for aphids in integrated pest management programmes in peach orchards. There are a number of primary parasitoid species associated with these aphids, and the nearby crops and wild vegetation in the vicinity and within the orchards may provide a suitable habitat for them. Additionally, some of them are commercially available and might be usable in augmentative releases. Full article

(This article belongs to the Special Issue Pest Control in Fruit Trees)

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14 pages, 1732 KiB

Open AccessArticle

Can Anastatus bifasciatus Be Used for Augmentative Biological Control of the Brown Marmorated Stink Bug in Fruit Orchards?

by Judith M. Stahl, Dirk Babendreier, Cristina Marazzi, Stefano Caruso, Elena Costi, Lara Maistrello and Tim Haye

Insects 2019, 10(4), 108; https://doi.org/10.3390/insects10040108 - 15 Apr 2019

Cited by 31 | Viewed by 5095

Abstract

The generalist egg parasitoid Anastatus bifasciatus (Geoffroy) (Hymenoptera: Eupelmidae) is the most prevalent egg parasitoid of the invasive Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) in Europe. To assess its efficacy against the pest H. halys and to validate the potential risks for non-target species [...] Read more.

The generalist egg parasitoid Anastatus bifasciatus (Geoffroy) (Hymenoptera: Eupelmidae) is the most prevalent egg parasitoid of the invasive Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) in Europe. To assess its efficacy against the pest H. halys and to validate the potential risks for non-target species in a realistic field setting, inundative releases were conducted over three consecutive years in four fruit orchards in Switzerland and Italy. In total, more than 4300 A. bifasciatus females were released, which was equivalent to 11,000 to 26,000 females per hectare, depending on distances between trees in each orchard. Parasitism of freeze-killed sentinel H. halys eggs achieved with the current release strategy was on average 6% (range: 2%–16%) and considered not high enough to effectively suppress the pest. However, the overall impact of A. bifasciatus on the mortality of H. halys eggs was likely underestimated. If pre-imaginal parasitoid mortality (3.3%) and host feeding (6%) are added to the observed parasitism (6%), the actual induced mortality of H. halys eggs may reach more than 15%. Parasitism of lepidopteran non-target species reached an average of 8% and thus, some degree of non-target parasitism after mass releases may be expected. To quantify the impact of the parasitoids in the orchards more precisely, naturally laid egg masses should be used in future trials to include host-finding cues of the host and host plants, and larger scale releases with potentially higher densities of parasitoids should be considered. Full article

(This article belongs to the Special Issue Pest Control in Fruit Trees)

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15 pages, 2226 KiB

Open AccessReview

Hemipteran Pests of Sugarcane in North America

by Blake E. Wilson

Insects 2019, 10(4), 107; https://doi.org/10.3390/insects10040107 - 14 Apr 2019

Cited by 7 | Viewed by 5921

Abstract

Piercing-sucking herbivores (Insecta: Hemiptera) represent one of the greatest threats to agricultural production worldwide. Hemipteran pests directly injure plants as well as vector disease-causing plant pathogens. Production of sugarcane (Saccharum spp.) in North America is impacted by a complex of Hemiptera including [...] Read more.

Piercing-sucking herbivores (Insecta: Hemiptera) represent one of the greatest threats to agricultural production worldwide. Hemipteran pests directly injure plants as well as vector disease-causing plant pathogens. Production of sugarcane (Saccharum spp.) in North America is impacted by a complex of Hemiptera including the sugarcane aphid, Melanaphis sacchari Zehntner (Aphididae); yellow sugarcane aphid, Sipha flava (Forbes) (Aphididae); West Indian canefly, Saccharosydne saccharivora (Westwood) (Delphacidae); sugarcane delphacid, Perkinsiella saccharicida Kirkaldy (Delphacidae); and sugarcane lace bug, Leptodictya tabida (Herric-Schaeffer) (Tingidae). None of these pests is consistently damaging to large amounts of sugarcane acreage, but regional outbreaks are common. The biology, ecology, and pest management of these insects are discussed with emphasis on North America sugarcane production. Full article

(This article belongs to the Special Issue Ecology and Pest Management of Sugarcane Insects)

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14 pages, 2071 KiB

Open AccessArticle

Current Status of Forest Health Policy in the United States

by Kamal J. K. Gandhi, Faith Campbell and Jesse Abrams

Insects 2019, 10(4), 106; https://doi.org/10.3390/insects10040106 - 12 Apr 2019

Cited by 3 | Viewed by 3032

Abstract

Federal policies related to forestry and forest health (specifically, insects and diseases) have the potential to affect management practices, terms of international and interstate trade, and long-term sustainability and conservation. Our objectives were to review existing federal policies, the role of federal agencies [...] Read more.

Federal policies related to forestry and forest health (specifically, insects and diseases) have the potential to affect management practices, terms of international and interstate trade, and long-term sustainability and conservation. Our objectives were to review existing federal policies, the role of federal agencies in managing forest health, and guidance for future policy efforts. Since the 1940s, various federal policies relevant to forest health have been established, and several US Department of Agriculture (USDA) agencies have been empowered to assist with prevention, quarantine, detection, management, and control of insects and diseases. Overall, our review showed that relatively few national policies directly address forest health as a stand-alone objective, as most of them are embedded within forestry bills. Federal funding for forest health issues and the number of personnel dedicated to such issues have declined dramatically for some agencies. Concomitantly, native species continue to gain pestiferous status while non-native species continue to establish and cause impacts in the US. To enhance our ability and capacity to deal with current and future threats, concerted efforts are needed to advocate for both resources and stand-alone policy tools that take seriously the complexity of emerging sustainability challenges in both private and public forestlands. Full article

(This article belongs to the Special Issue Ecology and Management of Forest Insects in a Changing World)

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12 pages, 1370 KiB

Open AccessArticle

Acoustic, Pitfall Trap, and Visual Surveys of Stored Product Insect Pests in Kenyan Warehouses

by Anastasia Njoroge, Hippolyte Affognon, Uwe Richter, Oliver Hensel, Barukh Rohde, Davie Chen and Richard Mankin

Insects 2019, 10(4), 105; https://doi.org/10.3390/insects10040105 - 12 Apr 2019

Cited by 8 | Viewed by 3785

Abstract

Grain production is an important component of food security in Kenya but due to environmental conditions that favor rapid growth of insect populations, farmers and other agricultural stakeholders face ongoing and novel challenges from crop and stored product pest insects. To assist development [...] Read more.

Grain production is an important component of food security in Kenya but due to environmental conditions that favor rapid growth of insect populations, farmers and other agricultural stakeholders face ongoing and novel challenges from crop and stored product pest insects. To assist development of methods to reduce economic losses from stored product insect pests in Kenya, acoustic, visual, and pitfall trap surveys were conducted in five grain storage warehouses. Two commercially available acoustic systems successfully detected the pests of greatest economic importance, Sitophilus zeamais (Motschulsky) and Prostephanus truncatus (Horn). Other insects of lesser economic importance also were observed in the visual surveys, including Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), and Tribolium castaneum (Herbst). This study demonstrated that the use of acoustic technology with visual surveys and pitfall traps can help managers to identify and target infestations within their warehouses, enabling them to reduce postharvest losses. With most warehouses being located in relatively noisy urban or peri-urban areas, background noise considerations are being incorporated into the design of future acoustic detectors for stored pest infestations. Kenya must import grain yearly to meet consumption needs; however, if the current yearly postharvest losses of 20–30% in warehouses decreased, import costs could be reduced considerably. Full article

(This article belongs to the Special Issue Improving Stored Product Insect Pest Management)

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9 pages, 4318 KiB

Open AccessArticle

First Record of the Velvet Ant Mutilla europaea (Hymenoptera: Mutillidae) Parasitizing the Bumblebee Bombus breviceps (Hymenoptera: Apidae)

by Wenting Su, Cheng Liang, Guiling Ding, Yusuo Jiang, Jiaxing Huang and Jie Wu

Insects 2019, 10(4), 104; https://doi.org/10.3390/insects10040104 - 12 Apr 2019

Cited by 3 | Viewed by 4608

Abstract

Mutillid wasps are ectoparasitic insects that parasitize the enclosed developmental stages of their hosts. Adults are sexually dimorphic, with brilliantly colored and hardened cuticles. The biology of parasitic mutillid wasps has rarely been addressed. Here, we investigated the parasitization by Mutilla europaea on [...] Read more.

Mutillid wasps are ectoparasitic insects that parasitize the enclosed developmental stages of their hosts. Adults are sexually dimorphic, with brilliantly colored and hardened cuticles. The biology of parasitic mutillid wasps has rarely been addressed. Here, we investigated the parasitization by Mutilla europaea on an important pollinator, Bombus breviceps. The parasitic biology and dispersal ability of M. europaea were observed and tested under experimental conditions. We provide the first record of M. europaea parasitizing B. breviceps in southwestern China. As is the case with other bumblebee species, M. europaea mainly parasitized the puparia of males. The dispersal and invasion ability of this parasite under experimental conditions indicates that it spreads rapidly, as far as 20 m in one week, and invades different hosts (B. breviceps and Bombus haemorrhoidalis). This report not only clarifies the parasitic relationship between M. europaea and B. breviceps, but also has important ecological implications for the conservation of bumblebees in China. Full article

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26 pages, 5898 KiB

Open AccessArticle

Phylogenetic Community Structure and Niche Differentiation in Termites of the Tropical Dry Forests of Colombia

by Robin Casalla Daza and Judith Korb

Insects 2019, 10(4), 103; https://doi.org/10.3390/insects10040103 - 10 Apr 2019

Cited by 1 | Viewed by 3139

Abstract

The mechanisms that structure species communities are still debated. We addressed this question for termite assemblages from tropical dry forests in Colombia. These forests are endangered and poorly understood ecosystems and termites are important ecosystem engineers in the tropics. Using biodiversity and environmental [...] Read more.

The mechanisms that structure species communities are still debated. We addressed this question for termite assemblages from tropical dry forests in Colombia. These forests are endangered and poorly understood ecosystems and termites are important ecosystem engineers in the tropics. Using biodiversity and environmental data, combined with phylogenetic community analyses, trait mapping, and stable isotopes studies, we investigated the termite community composition of three protected dry forests in Colombia. Our data suggest that the structuring mechanisms differed between sites. Phylogenetic overdispersion of termite assemblages correlated with decreasing rainfall and elevation and increasing temperature. Food niche traits—classified as feeding groups and quantified by δ¹⁵N‰ and δ¹³C‰ isotope signatures—were phylogenetically conserved. Hence, the overdispersion pattern implies increasing interspecific competition with decreasing drier and warmer conditions, which is also supported by fewer species occurring at the driest site. Our results are in line with a hypothesis that decreased biomass production limits resource availability for termites, which leads to competition. Along with this comes a diet shift: termites from drier plots had higher δ¹³C signatures, reflecting higher δ¹³C values in the litter and more C4 plants. Our study shows how a phylogenetic community approach combined with trait analyses can contribute to gaining the first insights into mechanisms structuring whole termite assemblages. Full article

(This article belongs to the Special Issue Ecology of Termites)

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11 pages, 224 KiB

Open AccessReview

Cardiac Glycosides in Human Physiology and Disease: Update for Entomologists

by Rif S. El-Mallakh, Kanwarjeet S. Brar and Rajashekar Reddy Yeruva

Insects 2019, 10(4), 102; https://doi.org/10.3390/insects10040102 - 10 Apr 2019

Cited by 18 | Viewed by 5175

Abstract

Cardiac glycosides, cardenolides and bufadienolides, are elaborated by several plant or animal species to prevent grazing or predation. Entomologists have characterized several insect species that have evolved the ability to sequester these glycosides in their tissues to reduce their palatability and, thus, reduce [...] Read more.

Cardiac glycosides, cardenolides and bufadienolides, are elaborated by several plant or animal species to prevent grazing or predation. Entomologists have characterized several insect species that have evolved the ability to sequester these glycosides in their tissues to reduce their palatability and, thus, reduce predation. Cardiac glycosides are known to interact with the sodium- and potassium-activated adenosine triphosphatase, or sodium pump, through a specific receptor-binding site. Over the last couple of decades, and since entomologic studies, it has become clear that mammals synthesize endogenous cardenolides that closely resemble or are identical to compounds of plant origin and those sequestered by insects. The most important of these are ouabain-like compounds. These compounds are essential for the regulation of normal ionic physiology in mammals. Importantly, at physiologic picomolar or nanomolar concentrations, endogenous ouabain, a cardenolide, stimulates the sodium pump, activates second messengers, and may even function as a growth factor. This is in contrast to the pharmacologic or toxic micromolar or milimolar concentrations achieved after consumption of exogenous cardenolides (by consuming medications, plants, or insects), which inhibit the pump and result in either a desired medical outcome, or the toxic consequence of sodium pump inhibition. Full article

11 pages, 785 KiB

Open AccessArticle

Gamma Radiation Sterilization Dose of Adult Males in Asian Tiger Mosquito Pupae

by Andre Ricardo Machi, Raquel Rodrigues Mayne, Márcio Adriani Gava, Paula Bergamin Arthur and Valter Arthur

Insects 2019, 10(4), 101; https://doi.org/10.3390/insects10040101 - 08 Apr 2019

Cited by 8 | Viewed by 4185

Abstract

The pathogen-carrying tiger mosquito, Aedes albopictus, has spread from the Western Pacific and Southeast Asia to Europe, Africa, the Middle East, North and South America, and the Caribbean. This species of mosquito transmits arboviral infections, such as yellow fever, chikungunya, dengue, zika, [...] Read more.

The pathogen-carrying tiger mosquito, Aedes albopictus, has spread from the Western Pacific and Southeast Asia to Europe, Africa, the Middle East, North and South America, and the Caribbean. This species of mosquito transmits arboviral infections, such as yellow fever, chikungunya, dengue, zika, and several encephalitides. The objective of this research was to provide a radiation dose inducing sterilization in adult male Ae. albopictus in the pupal stage. A cobalt-60 source of gamma radiation at a dose rate of 381 Gy/h was used. The pupae were irradiated with doses of 0 (control), 20, 30, 40, 50, and 60 Gy. Each treatment had a total of five replications using 60 pupae. After irradiation, the different phases of Ae. albopictus development (egg, larva, pupa, and adult) in the F1 generation were observed daily. Parameters such as viability, fertility, longevity, and mortality were recorded. The results from these studies showed that a dose of 60 Gy was necessary to sterilize 100% of the male Ae. albopictus pupae. Full article

(This article belongs to the Special Issue Integrative Mosquito Biology: From Molecules to Ecosystems)

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20 pages, 274 KiB

Open AccessReview

Influences of Stored Product Insect Movements on Integrated Pest Management Decisions

by Fuji Jian

Insects 2019, 10(4), 100; https://doi.org/10.3390/insects10040100 - 07 Apr 2019

Cited by 43 | Viewed by 6346

Abstract

Insect movement inside and outside grain bulks and processed products influences pest management decisions. Movement allows insects to find essential food resources, shelters (refuges), warmer and/or humid locations, mating and egg-laying sites, even when they are rare in fields, buildings, mills, warehouses, and [...] Read more.

Insect movement inside and outside grain bulks and processed products influences pest management decisions. Movement allows insects to find essential food resources, shelters (refuges), warmer and/or humid locations, mating and egg-laying sites, even when they are rare in fields, buildings, mills, warehouses, and inside grain masses. This review discussed the advantages and disadvantages of stored product insect movements, and the influence of insect mobility on some integrated pest management practices. Insect movement (1) results in clumped insect spatial distributions and thus makes large sample sizes necessary for monitoring; (2) makes trapping more efficient, but is influenced by many factors; (3) allows control methods to be effective, but requires pest management programs to be area-wide; (4) makes eradication of quarantine pests difficult and commodities are quickly re-infested; and (5) results in a diverse genetic pool and speeds the development of resistance to pesticides. Any element of an IPM approach should use the knowledge of insect movement. Reasons for the difficult interpretation of cryptic movement behaviours of insects were provided and future research areas were suggested. Full article

(This article belongs to the Special Issue Improving Stored Product Insect Pest Management)

13 pages, 1542 KiB

Open AccessReview

Ecosystem Services, Global Diversity, and Rate of Stonefly Species Descriptions (Insecta: Plecoptera)

by R. Edward DeWalt and Geoffrey Donald Ower

Insects 2019, 10(4), 99; https://doi.org/10.3390/insects10040099 - 06 Apr 2019

Cited by 54 | Viewed by 5125

Abstract

Stoneflies (Insecta: Plecoptera) provide ecosystem services as indicators of water quality, as food for predators, as mediators of energy flow and nutrient cycling, and through cultural services related to recreation and artistic creativity. The Plecoptera Species File (PSF) aggregates stonefly nomenclature, distribution, and [...] Read more.

Stoneflies (Insecta: Plecoptera) provide ecosystem services as indicators of water quality, as food for predators, as mediators of energy flow and nutrient cycling, and through cultural services related to recreation and artistic creativity. The Plecoptera Species File (PSF) aggregates stonefly nomenclature, distribution, and literature to help society and scientists understand the value of services stoneflies provide. Using PSF data, we examined global and regional diversity, compared species description rates, and predicted future species description numbers through the year 2100. Through 2018, extant species totaled 3718 with Temperate Asia having the greatest regional diversity at 1178 species. The Perlidae was the most species-rich of the 16 families at 1120 species. The recent global rate of species description was 43.6 species/yr, with Temperate Asia having the highest regional rate at 13.7 species/yr, followed by China and South America adding approximately 9.0 species/yr. We predicted that 1140 ± 130 new species would be described globally by 2050, and 2130 ± 330 by the year 2100, most of the increase occurring in China and South America. We discuss the possibility of reaching these predicted values. Full article

(This article belongs to the Special Issue Diversity and Ecosystem Services of Aquatic Insects)

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12 pages, 2014 KiB

Open AccessArticle

Diversity, Daily Activity Patterns, and Pollination Effectiveness of the Insects Visiting Camellia osmantha, C. vietnamensis, and C. oleifera in South China

by Wei Wei, Haipan Wu, Xueyuan Li, Xing Wei, Wen Lu and Xialin Zheng

Insects 2019, 10(4), 98; https://doi.org/10.3390/insects10040098 - 02 Apr 2019

Cited by 10 | Viewed by 3391

Abstract

Camellia spp., which are self-incompatible plants, are some of the most important woody species producing edible oil in Southeast Asian countries. However, the demand for camellia oil currently exceeds the supply due to low product yields that have resulted from a decrease in [...] Read more.

Camellia spp., which are self-incompatible plants, are some of the most important woody species producing edible oil in Southeast Asian countries. However, the demand for camellia oil currently exceeds the supply due to low product yields that have resulted from a decrease in pollination services. Although Camellia osmantha, C. vietnamensis, and C. oleifera are cultivated in South China, little is known about the correspondence between pollinator abundance and pollinator services for this plant genus. In this study, the diversity, daily activity patterns, and pollination effectiveness of insects visiting C. osmantha, C. vietnamensis and C. oleifera were investigated. A total of 24 species, belonging to four orders and 11 families, of visiting insects were identified. Apis cerana cerana Fabricius, Vespa bicolor Fabricius, V. velutina Lepeletier, V. ducalis Smith, and Phytomia zonata Fabricius were the dominant pollinators. The daily activity peaks of the five visiting insects were between 10:00 and 14:00, which may have been related to the pattern of floral resource production (particularly nectar). Cross-pollination by insects significantly increased the fruit production rates of C. osmantha, C. vietnamensis, and C. oleifera. Therefore, the wild bees and flies that pollinate wild and cultivated Camellia plants should be protected in South China. Full article

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14 pages, 1295 KiB

Open AccessArticle

Increases in Genistein in Medicago sativa Confer Resistance against the Pisum Host Race of Acyrthosiphon pisum

by Erliang Yuan, Hongyu Yan, Jing Gao, Huijuan Guo, Feng Ge and Yucheng Sun

Insects 2019, 10(4), 97; https://doi.org/10.3390/insects10040097 - 01 Apr 2019

Cited by 10 | Viewed by 2785

Abstract

Interspecific interaction with host plants have important consequences for the host race formation of herbivorous insects. Plant secondary metabolites, particularly those that are involved in host races specializing on plants, warrant the theory of host specialization. Acyrthosiphon pisum comprises various host races that [...] Read more.

Interspecific interaction with host plants have important consequences for the host race formation of herbivorous insects. Plant secondary metabolites, particularly those that are involved in host races specializing on plants, warrant the theory of host specialization. Acyrthosiphon pisum comprises various host races that adapt to different Fabaceae plants, which provides an ideal system for determining the behavioral and physiological mechanisms underlying host-adaptive diversification. The current study evaluated the effects of host transfer on population fitness, feeding behavior and the transcriptome-wide gene expression of the two host races of A. pisum, one of which was originally from Medicago sativa and the other from Pisum sativum. The results showed that the Pisum host race of A. pisum had a lower population abundance and feeding efficiency than the Medicago host race in terms of a longer penetration time and shorter duration times of phloem ingestion when fed on M. sativa. In contrast, few differences were found in the population abundance and feeding behavior of A. pisum between the two host races when fed on P. sativum. Meanwhile, of the nine candidate phenolic compounds, only genistein was significantly affected by aphid infestation; higher levels of genistein were detected in M. sativa after feeding by the Pisum host race, but these levels were reduced relative to uninfested controls after feeding by the Medicago host race, which suggested that genistein may be involved in the specialization of the aphid host race on M. sativa. Further exogenous application of genistein in artificial diets showed that the increase in genistein reduced the survival rate of the Pisum host race but had little effect on that of the Medicago host race. The transcriptomic profiles indicated that the transcripts of six genes with functions related to detoxification were up-regulated in the Pisum host race relative to the Medicago host race of A. pisum. These results suggested that the inducible plant phenolics and associated metabolic process in aphids resulted in their differential adaptations to their Fabaceae host. Full article

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11 pages, 1107 KiB

Open AccessBrief Report

Commercially Available Essential Oil Formulas as Repellents Against the Stored-Product Pest Alphitobius diaperinus

by Jacek Francikowski, Bartosz Baran, Mikołaj Cup, Jakub Janiec and Michał Krzyżowski

Insects 2019, 10(4), 96; https://doi.org/10.3390/insects10040096 - 01 Apr 2019

Cited by 20 | Viewed by 3659

Abstract

The main aim of the presented paper is to assess the potential repellent effect of selected essential oils (EOs) against the lesser mealworm (Alphitobius diaperinus), which can cause economic losses in storage and in the poultry industry. Due to the development [...] Read more.

The main aim of the presented paper is to assess the potential repellent effect of selected essential oils (EOs) against the lesser mealworm (Alphitobius diaperinus), which can cause economic losses in storage and in the poultry industry. Due to the development of pesticide resistance in A. diaperinus populations, as well as an attempt to limit extensive use of potentially harmful pesticides in food-related industries, there is a strong need for the development of alternative methods of dealing with A. diaperinus infestations. Because of their cost-effectiveness, availability and low vertebrate toxicity, EOs are promising agents in pest management. In the presented paper four off-the-shelf EOs: mint, vanilla, lemon and citronella (and mixtures of them) were tested as potential repellents. Moreover, a novel preference assay, providing an extended analysis of the preference and the locomotor response, was used. The most effective EOs were: citronella and lemon. EOs mixtures were generally more repellent than individual EOs, with the lemon and vanilla 1:1 mixture acting as the strongest repellent. A few of the tested EOs caused significant alterations to the locomotor activity, although no direct relation was observed. In conclusion, EOs can be potentially used as repellent agents in A. diaperinus management. Additionally, data on the locomotor activity may lead to designing better push-pull strategies in pest management. Full article

(This article belongs to the Special Issue Improving Stored Product Insect Pest Management)

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9 pages, 671 KiB

Open AccessArticle

Residual Efficacy of a Deltamethrin Emulsifiable Concentrate Formulation against Rhyzopertha dominica (F.) and Sitotroga cerealella (Oliver) after Partial Treatment of Brown Rice

by Frank H. Arthur

Insects 2019, 10(4), 95; https://doi.org/10.3390/insects10040095 - 01 Apr 2019

Cited by 14 | Viewed by 2922

Abstract

Rhyzopertha dominica (Fab.), the lesser grain borer, and Sitotroga cerealella (Olivier), the Angoumois grain moth, are internally feeding stored product insects that can infest raw grains. In this test, brown rice was treated with 0.5 and 1.0 ppm of a new emulsifiable concentrate [...] Read more.

Rhyzopertha dominica (Fab.), the lesser grain borer, and Sitotroga cerealella (Olivier), the Angoumois grain moth, are internally feeding stored product insects that can infest raw grains. In this test, brown rice was treated with 0.5 and 1.0 ppm of a new emulsifiable concentrate (EC) formulation of the pyrethroid deltamethrin and stored for 12 months. One day after treatment, and every 3 months for 12 months, treated rice was mixed with untreated brown rice in the following ratios: 0:100 (untreated controls), 10:90, 25:75, 50:50, 75:25, and 100:0 (all treated). Bioassays were conducted by exposing 10 parental adults of each species on the rice mixtures and assessing progeny production, feeding damage, and weight loss. The progeny of S. cerealella ranged from 105.6 F₁ adults on untreated brown rice to 69.4 F₁ adults on 100% treated rice, but there was little feeding damage or weight loss. The progeny production of R. dominica declined from 177.4 F₁ adults on untreated rice to 9.8 F₁ adults on 100% treated rice. Weight loss and feeding damage were correlated with progeny production. The results show that the new deltamethrin formulation could be used for protection of brown rice, but S. cerealella may be less susceptible to deltamethrin compared to R. dominica. Full article

(This article belongs to the Special Issue Improving Stored Product Insect Pest Management)

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15 pages, 1874 KiB

Open AccessReview

Efficacy of Two Entomopathogenic Fungi, Metarhizium brunneum, Strain F52 Alone and Combined with Paranosema locustae against the Migratory Grasshopper, Melanoplus sanguinipes, under Laboratory and Greenhouse Conditions

by Wahid H. Dakhel, Alexandre V. Latchininsky and Stefan T. Jaronski

Insects 2019, 10(4), 94; https://doi.org/10.3390/insects10040094 - 30 Mar 2019

Cited by 16 | Viewed by 4665

Abstract

Grasshopper outbreaks cause significant damage to crops and grasslands in US. Chemical control is widely used to suppress these pests but it reduces environmental quality. Biological control of insect pests is an alternative way to reduce the use of chemical insecticides. In this [...] Read more.

Grasshopper outbreaks cause significant damage to crops and grasslands in US. Chemical control is widely used to suppress these pests but it reduces environmental quality. Biological control of insect pests is an alternative way to reduce the use of chemical insecticides. In this context, two entomopathogenic fungi, Metarhizium brunneum strain F52 and Paranosema locustae were evaluated as control agents for the pest migratory grasshopper Melanoplus sanguinipes under laboratory and greenhouse conditions. Third-instar grasshoppers, reared in the laboratory, were exposed up to fourteen days to wheat bran treated with different concentrations of each of the fungi alone or the two pathogens combined. In the greenhouse, nymphs were placed individually in cages where they were able to increase their body temperatures by basking in the sun in an attempt to inhibit the fungal infection, and treated with each pathogen alone or in combination. Mortality was recorded daily and presence of fungal outgrowth in cadavers was confirmed by recording fungal mycosis for two weeks’ post-treatment (PT). For combination treatment, the nature of the pathogen interaction (synergistic, additive, or antagonistic effects) was also determined. In laboratory conditions, all treatments except P. locustae alone resulted in grasshopper mortality. The application of the pathogen combinations caused 75% and 77%, mortality for lower and higher concentrations, respectively than each of the pathogens alone. We infer a synergistic effect occurred between the two agents. In greenhouse conditions, the highest mortalities were recorded in combination fungal treatments with a M. brunneum dose (60% mortality) and with a combination of the two pathogens in which M. brunneum was applied at high rate (50%) two weeks after application. This latter combination also exhibited a synergistic effect. Exposure to the P. locustae treatment did not lead to mortality until day 14 PT. We infer that these pathogens are promising for developing a biopesticide formulation for rangeland pest grasshopper management. Full article

(This article belongs to the Special Issue Biological Control of Plant Pests in Protected Culture)

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20 pages, 2151 KiB

Open AccessArticle

Using Long-term Capture Data to Predict Trogoderma variabile Ballion and Plodia interpunctella (Hübner) Population Patterns

by Alison R. Gerken and James F. Campbell

Insects 2019, 10(4), 93; https://doi.org/10.3390/insects10040093 - 30 Mar 2019

Cited by 13 | Viewed by 3884

Abstract

Insects can infest facilities that house and process post-harvest grains and grain-based products. Integrated pest management tactics rely on tracking insect populations and using this information to select and target management tactics. Our ability to predict when and where to best focus treatment [...] Read more.

Insects can infest facilities that house and process post-harvest grains and grain-based products. Integrated pest management tactics rely on tracking insect populations and using this information to select and target management tactics. Our ability to predict when and where to best focus treatment relies on an understanding of long-term trends, but often any available monitoring data are limited in its duration. Here we present data collected over a 10-year period at a flour mill in the central part of the United States. Using traps placed both inside and outside a flour mill and baited with pheromone-lures for Plodia interpunctella (Hübner), Indianmeal moth, and Trogoderma variabile Ballion, warehouse beetle, we examine environmental and spatial variability in insect captures. We find that both species, inside and outside the mill, are highly influenced by seasonal patterns, with peaks of insect captures during the warm season (April through September). There is also consistency across time and space in trap capture for P. interpunctella with traps in an open location consistently capturing high numbers of insects. In contrast, T. variabile lacked consistency in trap capture but were most often not found in the same trap locations as P. interpunctella. Fumigations conducted within the facility appeared to have little impact on insect captures inside, with dynamics appearing to be driven more by broader seasonal patterns in activity. These data and analyses suggest that there is a larger population of these insects that are readily moving in and out of the structures, while fumigation treatments are only impacting a small portion of the overall population and tactics targeting immigration may be an important addition to the pest management program. Full article

(This article belongs to the Special Issue Improving Stored Product Insect Pest Management)

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10 pages, 941 KiB

Open AccessArticle

Telenomus remus, a Candidate Parasitoid for the Biological Control of Spodoptera frugiperda in Africa, is already Present on the Continent

by Marc Kenis, Hannalene du Plessis, Johnnie Van den Berg, Malick Niango Ba, Georg Goergen, Koffi Eric Kwadjo, Ibrahim Baoua, Tadele Tefera, Alan Buddie, Giovanni Cafà, Lisa Offord, Ivan Rwomushana and Andrew Polaszek

Insects 2019, 10(4), 92; https://doi.org/10.3390/insects10040092 - 29 Mar 2019

Cited by 93 | Viewed by 15364

Abstract

The fall armyworm, Spodoptera frugiperda, a moth originating from tropical and subtropical America, has recently become a serious pest of cereals in sub-Saharan Africa. Biological control offers an economically and environmentally safer alternative to synthetic insecticides that are being used for the [...] Read more.

The fall armyworm, Spodoptera frugiperda, a moth originating from tropical and subtropical America, has recently become a serious pest of cereals in sub-Saharan Africa. Biological control offers an economically and environmentally safer alternative to synthetic insecticides that are being used for the management of this pest. Consequently, various biological control options are being considered, including the introduction of Telenomus remus, the main egg parasitoid of S. frugiperda in the Americas, where it is already used in augmentative biological control programmes. During surveys in South, West, and East Africa, parasitized egg masses of S. frugiperda were collected, and the emerged parasitoids were identified through morphological observations and molecular analyses as T. remus. The presence of T. remus in Africa in at least five countries provides a great opportunity to develop augmentative biological control methods and register the parasitoid against S. frugiperda. Surveys should be carried out throughout Africa to assess the present distribution of T. remus on the continent, and the parasitoid could be re-distributed in the regions where it is absent, following national and international regulations. Classical biological control should focus on the importation of larval parasitoids from the Americas. Full article

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10 pages, 2192 KiB

Open AccessArticle

Effects of Different Pretreatments of DNA Extraction from Dried Specimens of Ladybird Beetles (Coleoptera: Coccinellidae)

by Weidong Huang, Xiufeng Xie, Xinyue Liang, Xingmin Wang and Xiaosheng Chen

Insects 2019, 10(4), 91; https://doi.org/10.3390/insects10040091 - 29 Mar 2019

Cited by 6 | Viewed by 3501

Abstract

Obtaining genetic information from museum specimens is a fundamental component of many fields of research, including DNA barcoding, population genetics, conservation genetics, and phylogenetic analysis. However, acquiring genetic information from museum specimens is challenging because of the difficulty in amplifying the target sequences [...] Read more.

Obtaining genetic information from museum specimens is a fundamental component of many fields of research, including DNA barcoding, population genetics, conservation genetics, and phylogenetic analysis. However, acquiring genetic information from museum specimens is challenging because of the difficulty in amplifying the target sequences due to DNA damage and degradation. Different pretreatments can significantly impact the purity and concentration of genomic DNA from museum specimens. Here, we assessed four pretreatment methods—use of 0.9% NaCl buffer, phosphate-buffered saline (PBS), Saline Tris-EDTA (STE) buffer, and sterile water—to determine which pretreatment is most suitable for DNA extraction from dried specimens of ladybird beetles. We completed a comprehensive phylogenetic analysis to test whether the sequences obtained from dried specimens enable proper phylogenetic inference. Our results showed that pretreatment can improve the quality of DNA from dried specimens. The pretreatment effects of 0.9% NaCl buffer and STE buffer were better than those of PBS buffer and sterile water. The phylogenetic analyses results showed that museum specimens can be used to generate cogent phylogenetic inferences. We report the optimum pretreatment methods for DNA extraction from dried ladybird beetles specimens as well as provide evidence for accurately determining phylogenetic relationships for museum specimens. Full article

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10 pages, 2497 KiB

Open AccessArticle

Insights into the Maternal Ancestry of Côte d’Ivoire Honeybees Using the Intergenic Region COI-COII

by Krouholé Abdoul Salam Coulibaly, Muhammad Zeeshan Majeed, Chao Chen, Kolo YEO, Wei Shi and Chun-Sen Ma

Insects 2019, 10(4), 90; https://doi.org/10.3390/insects10040090 - 29 Mar 2019

Cited by 4 | Viewed by 3369

Abstract

Honeybee populations in Côte d’Ivoire have been previously identified as belonging to one subspecies, Apis mellifera scutellata, but other studies have since reported a mixed population consisting of A. m. adansonii and A. m. jemenitica. The population structure and the geographic distribution [...] Read more.

Honeybee populations in Côte d’Ivoire have been previously identified as belonging to one subspecies, Apis mellifera scutellata, but other studies have since reported a mixed population consisting of A. m. adansonii and A. m. jemenitica. The population structure and the geographic distribution of honeybees in Côte d’Ivoire remain unclear. This study aimed to profile the population structure of honeybees and their biogeography in Côte d’Ivoire. A total of 33 honeybee colonies were sampled from 15 localities to investigate the maternal ancestry of indigenous honeybee populations using the DraI COI-COII mtDNA test. The results revealed that the honeybee population in Côte d’Ivoire is composed of African haplotypes, all belonging to the A_I sublineage. Haplotypes A₁ and A₄ were recorded with five new sequence variants, including three types of haplotype A₁ and two types of haplotype A₄. The A_1e variant was the most frequent in the A. m. adansonii distributional area. The distribution of the haplotype variants was correlated with the climate pattern in Côte d’Ivoire. This is the first study in Côte d’Ivoire that gives insights into the biogeography and mitotype structure of the local honeybee populations. Full article

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11 pages, 1288 KiB

Open AccessArticle

Aseptic Rearing and Infection with Gut Bacteria Improve the Fitness of Transgenic Diamondback Moth, Plutella xylostella

by Jasmine Somerville, Liqin Zhou and Ben Raymond

Insects 2019, 10(4), 89; https://doi.org/10.3390/insects10040089 - 28 Mar 2019

Cited by 18 | Viewed by 3980

Abstract

Mass insect rearing can have a range of applications, for example in biological control of pests. The competitive fitness of released insects is extremely important in a number of applications. Here, we investigated how to improve the fitness of a transgenic diamondback moth, [...] Read more.

Mass insect rearing can have a range of applications, for example in biological control of pests. The competitive fitness of released insects is extremely important in a number of applications. Here, we investigated how to improve the fitness of a transgenic diamondback moth, which has shown variation in mating ability when reared in different insectaries. Specifically we tested whether infection with a gut bacteria, Enterobacter cloacae, and aseptic rearing of larvae could improve insect growth and male performance. All larvae were readily infected with E. cloacae. Under aseptic rearing, pupal weights were reduced and there was a marginal reduction in larval survival. However, aseptic rearing substantially improved the fitness of transgenic males. In addition, under aseptic rearing, inoculation with E. cloacae increased pupal weights and male fitness, increasing the proportion of transgenic progeny from 20% to 30% relative to uninfected insects. Aseptic conditions may improve the fitness of transgenic males by excluding microbial contaminants, while symbiont inoculation could further improve fitness by providing additional protection against infection, or by normalizing insect physiology. The simple innovation of incorporating antibiotic into diet, and inoculating insects with symbiotic bacteria that are resistant to that antibiotic, could provide a readily transferable tool for other insect rearing systems. Full article

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