Journal of Insect Science最新文献

Gynaephora menyuanensis Yan & Zhou is one of the most devastating pests that harm the ecosystem of alpine meadows and hinder the advancement of animal husbandry. However, the current knowledge of the morphology of the different developmental stages within G. menyuanensis reveals an information deficit that needs to be addressed. This study is the first to report the life history, sexual dimorphism, and morphology of eggs, mature larvae, pupae, and adult antennal sensilla types of G. menyuanensis. This study used a K-means clustering method, based on the head width, body length, body width, and the number of crochets of larvae at each instar, to differentiate instars of G. menyuanensis; the description of the morphology of larvae, pupae, and adult antennae employed light microscopy and scanning electron microscopy photographs. The results revealed that the instar grouping was reliable and verified by the Brooks-Dyar combined with Crosby rules, revealing that the larval stage of G. menyuanensis comprises 7 instars. This species produces one generation per year in the alpine meadow, with its life cycle lasting approximately 300 d in total. The pupae and adult antennae significantly differed between the sexes, indicating sexual dimorphism in the 2 genders. Nine types and 14 subtypes of antennal sensilla were observed in male antennae (bipectinate), while only 3 types and 3 subtypes were found in female adult antennae (club-like). Our findings have implications for better understanding the life history, adaptation strategies under extreme environmental conditions on the Qinghai-Tibet Plateau and developing scientific and effective pest control methods.

Böhm's bristles are mechanosensory structures located on the basal segments of antennae of most insects and provide sensory feedback for antennal positioning. The bristles are located near the head-scape and scape-pedicel joints, and evidence demonstrates that as the joints bend, the bristles are mechanically deflected by contact with the reconfiguring flexible cuticle of the joint, providing sensory information about joint angles. If the Böhm's bristles are only detecting joint position, and the full range of motion of that joint is detected by the array of Böhm's bristles, it follows that the extent of the array should correspond to the length of the segment covered by the flexible cuticle during bending. The spatial arrangement of the bristles should provide insight into the joint movement range, joint type, and the resolution of the joint angle available as sensory input. To evaluate this, we characterized the Böhm's bristles in Acheta domesticus (L.) (two hinge joints) using scanning electron microscopy (SEM). Our SEM analysis revealed one field of Böhm's bristles on the dorsal side and two on the ventral side of the scape, and two additional fields of Böhm's bristles on the lateral and medial sides of the pedicel. Bristles are positioned such that they are all deflected when the scape or pedicel is completely bent; thus, the arrangement of bristles matches the range of joint movement. In addition, we suggest that the number of bristles in the direction of joint movement may indicate the resolution of detection of the movement of the joint.

The wheat stem sawfly, Cephus cinctus Norton, is a major pest of cultivated wheat (Triticum aestivum L.) and other cereals in North America. The native congeneric parasitoids Bracon cephi (Gahan) and B. lissogaster Muesebeck are important biocontrol agents and play a crucial role in managing wheat stem sawfly outbreaks and damage. Smooth brome grass (Bromus inermis Leyss) has been found to be an effective wheat stem sawfly sink and parasitoid source when grown in areas neighboring wheat fields in Montana. To better understand the ecology of the system, we investigated both the wheat stem sawfly-induced volatile organic compounds produced by smooth brome and winter wheat, and the electrophysiological and behavioral response of B. cephi and B. lissogaster to the collected volatiles via coupled electroantennography and gas chromatography-flame ionization detection. Volatile concentration analysis indicated significantly increased production of (Z)-3-hexenyl acetate, 6-methyl-5-hepten-2-one, and (E)-2-hexenal in wheat stem sawfly-infested smooth brome, and elevated production of 6-methyl-5-hepten-2-one in infested smooth brome and winter wheat when compared to their uninfested counterparts. Both B. cephi and B. lissogaster exhibited significant electrophysiological and behavioral response to (Z)-3-hexenyl acetate, 6-methyl-5-hepten-2-one, and hexahydrofarnesyl acetone. Our results provide important evidence supporting habitat management recommendations that will enhance the effectiveness of biological control, contributing to more sustainable agricultural practices and the preservation of vital ecological functions.

Spotted wing drosophila, Drosophila suzukii (Matsumura), native to Asia, has become a significant threat to soft fruit crops globally. To develop a classical biological control program for this pest, the obligate parasitoid Ganaspis kimorum (Buffington) was approved in the United States for field release in 2021 as a biological control agent. However, challenges in mass production and maintenance of parasitoid colonies have been common. Here, we share improved methods and offer insights into mitigating issues that limit parasitoid production. Additionally, we present a modified rearing protocol using 2-l plastic containers to produce an average of 307 G. kimorum per container. This information is crucial for implementing successful classical biological control programs against spotted wing drosophila with this parasitoid.

This research evaluated the AedesTech Mosquito Home System (AMHS), an ovitrap employing autodissemination with pyriproxyfen, to monitor and manage mosquito populations. It involved 3 studies of the AMHS: a baseline study, an effectiveness study, and an autodissemination study on Aedes (Diptera: Culicidae) mosquitoes. Forty AHMS units filled with water were deployed for the baseline study. During the effectiveness study, 40 untreated AMHS units with water were placed alongside 40 AMHS units treated with Mosquito Home Aqua (MHAQ) solution, the retail solution used for AMHS. The autodissemination study featured 40 AMHS units treated with MHAQ alongside 40 control AMHS units without MHAQ, together with 25 Aedes aegypti (Linnaeus) larvae. Notably, treated traps in the effectiveness study exhibited a significant reduction in the Ovitrap Index (OI) compared to the baseline traps in the baseline study. The effectiveness study validated AMHS's efficacy, with treated traps displaying a significantly lower OI than untreated counterparts (P < 0.05). The study also showed a decrease in the percentage of egg hatching and percentage of adult emergence in treated traps compared to untreated traps. Autodissemination was evident, marked by a significant percentage of adult emergence decrease of Ae. aegypti larvae, without affecting sex ratios. It strongly suggests that AMHS can effectively reduce Aedes populations through direct contact and autodissemination without affecting sex ratios.

We report the establishment of the invasive eucalyptus weevil Gonipterus platensis in the high elevation Nilgiri Plateau in the state of Tamil Nadu, India. Its presence was first brought to light by observations uploaded on iNaturalist, a citizen science platform, from Eucalyptus globulus plantations. Specimens collected from the plantations were examined morphologically and dissected to reveal the diagnostic characters of G. platensis. DNA sequences of the cytochrome c oxidase gene (COI) amplified from Indian specimens were 0.3% different from G. platensis sequences from Tasmanian populations and over 4% different from any other Gonipterus species for which DNA data are available. Sequence data from 6 invasive populations of G. platensis indicates multiple, independent invasions from a Tasmanian source population to different parts of the world. The collection of specimens, including larvae, over multiple years indicates that the population in the Nilgiris is persistent, with the earliest evidence for its presence in the region being March 2019. We recommend further monitoring and assessment of population growth and spread of Gonipterus platensis to minimize the economic impact of this potentially important pest of Eucalyptus in India. Citizen science played a critical role in this discovery, and we recommend that subject experts engage with nature enthusiasts on platforms like iNaturalist so that the wide reach of public participation is harnessed to effectively monitor biodiversity.

The external and internal structures of adult males and females of Culicoides grisescens Edwards were examined using scanning electron microscopy (SEM) and tissue sectioning techniques. Specimens were collected from Qilian Mountain National Park in Qinghai Province, China. The ultrastructure and morphology of the compound eyes, antennae, maxillary palpi, spermathecae, genitalia, and other structural features both male and female adults of C. grisescens are described. Significant morphological differences between the two sexes were observed. The female has a pair of large mandibles with 16 teeth arranged in two rows. The first row contains 16 teeth, while the second row is located near the terminal teeth at the lower part. In contrast, the male mandibles have 2 to 3 teeth, totaling over 20, with a slender structure and small teeth distributed near the center at the terminal end of the mandibles. The tip of the male tongue is narrower and triangular than in shape compared to the female. Additionally, there are significant differences in the shape of the antennae and the types of antennal sensilla between males and females. This study also observed that the middle lobe of the male masculine stem is V-shaped, and the terminal end of the masculine lateral process is bifurcated, featuring 5 to 7 slender, finger-like branches. These unique morphological structures are useful for distinguishing male Culicoides from each other. For the first time, this paper describes the internal structures of this species, including histological sections of the digestive, nervous, respiratory, and reproductive systems. The findings presented herein provide both visual and descriptive details for the systematic taxonomic study of Ceratopogonidae, highlighting their significant economic and medical importance.

Insects that infest postharvest commodities cause significant damage or destruction, costing billions of dollars in lost products yearly. Insecticide treatments applied as contact insecticides are effective in managing insect populations. However, recovery of the insects after exposure to these insecticides is increased if food is present, reducing the efficacy of surface treatments and leading to continued infestations. In addition, variation in temperature and humidity could play a significant role in recovery. Here, we assess the role of food, temperature, and humidity on the recovery of Tribolium castaneum Herbst, red flour beetle, after exposure to a contact insecticide. We found food is an important factor in recovery under different temperature and humidity conditions. While recovery was higher at warmer temperatures and higher humidities, recovery increased further when food was present versus absent. Moreover, we found that any amount of flour, even a dusting, resulted in over 90% of beetles recovering after insecticide exposure, but when sand was substituted for flour, recovery was 25% lower compared to a no food treatment. These results highlight the importance of how environmental factors and the availability of food influence efficacy of insecticide treatments. Sanitation in food facilities is critically important as even the smallest amount of food present can cause substantial recovery, allowing beetles to escape treated areas and move throughout facilities. Further work pinpointing variation in underlying recovery between different populations and among different insect species is needed to understand local adaptation potential.

Insects use volatile organic compounds (VOCs) as environmental cues for resource-searching. Volatile cues provide information that can attract pollinators and natural enemies or repel crop pests. Naturally occurring VOCs are valuable tools for controlling and monitoring pests as part of integrative pest management strategies. However, their effectiveness as monitoring tools depends on the surrounding context, emphasizing the importance of evaluating their performance within the specific conditions in which they will be deployed. Delia platura (Meigen), or seedcorn maggot, is a globally distributed pest, often feeding on seeds of legumes, allium, and cereal grains. Adults of this pest rely on olfaction when searching for oviposition sites. To determine which cues are more attractive for D. platura, and if the attraction to certain cues depends on the surrounding crop context, a 2-factorial blocked experiment was conducted to test the individual and combined effects of previously reported attractants (silage alfalfa, fresh alfalfa, manure, fish meal, bone meal, soil, a commercially available attractant and control soils) and at-risk crop species (field corn, soybean, and snap bean) on adult response. There were differences between attractants and seed types but no interactions. Traps containing silage alfalfa attracted more flies than the controls and the commercially available attractant. Traps containing corn attracted more flies than those containing soybean. These results indicate that D. platura uses volatile cues to differentiate among attractant sources and seed types, and that future management practices could use the same attractant across the 3 crop systems.