Frontiers in insect science最新文献

Insect trap networks targeting agricultural pests are commonplace but seldom optimized to improve precision or efficiency. Trap site selection is often driven by user convenience or predetermined trap densities relative to sensitive host crop abundance in the landscape. Monitoring for invasive pests often requires expedient decisions based on dispersal potential and ecology to inform trap placement. Optimization of trap networks using contemporary analytical approaches can help users determine the distribution of traps as information accumulates and priorities change. In this study, a Bayesian optimization (BO) algorithm was used to learn more about the optimal distribution of a fine-scale trap network targeting Helicoverpa zea (Boddie), a significant agricultural pest across North America. Four years of pheromone trap monitoring was conducted at the same 21 locations distributed across ~7,000 square kilometers in a five-county area in North Carolina, USA. Three years of data were used to train a BO model with a fourth year designated for testing. For any quantity of trap locations, the approach identified those that provide the most information, allowing optimization of trapping efficiency given either a constraint on the number of locations, or a set precision required for pest density estimation. Results suggest that BO is a powerful approach to enable optimized trap placement decisions by practitioners given finite resources and time.

Agrotis ipsilon (Lepidoptera: Noctuidae) is a significant pest in Oregon grass seed and vegetable production systems. Effective management of this species relies on timely foliar insecticide applications targeting immature A. ipsilon larvae before crop damage is observed. Regionally specific phenological models serve as a critical component of effective areawide pest management plans to inform the timing of pest monitoring and management action. Seasonal modeling of A. ipsilon phenology is complicated by their migratory behavior and limited knowledge of temperature-dependent development on affected crop hosts. Growth chamber experiments at five constant temperatures (12 to 32°C) were conducted to determine the temperature-dependent development of A. ispsilon life stages on an artificial and perennial ryegrass diet. The completion of one A. ipsilon generation (egg-to-adult) required 658.71 ± 31.49, 601.98 ± 16.01, 648.47 ± 21.35 degree days with a base temperature threshold of 9.8°C for artificial diet, perennial ryegrass diet, and across both diet types, respectively. The timing of migrant adults was predicted with surface air temperature using non-linear regression with A. ipsilon abundance data collected from pheromone-baited traps in 77 total commercial grass seed (n = 57) and vegetable (n = 20) production fields across 19 sampling years (1996 to 2023). Developmental parameters and predictions of adult arrival were used to develop general and grass seed specific phenology model projections for A. ipsilon populations in Oregon. Regionally validated phenology models can be incorporated into decision support tools to forecast the spatiotemporal occurrence of crop-damaging life stages of priority insect pests.

Extracts of plants have been used to manage various insect pests, but little information is available about how effective they are in reducing crop damage or how they affect crop yield and beneficial insects in rice. Extracts from Azadirachta indica leaves, Lantana camara leaves, Nerium oleander leaves, Aegle marmelos leaves, Allium sativum cloves, and Citrus limon fruits, known to have insecticidal properties, were compared with two checks, viz., Azadirachtin 1% EC and standard insecticide Acephate 95 SG, for their efficacy against yellow stem borer (YSB), Scirpophaga incertulas (Walk.), and rice leaf folder Cnaphalocrocis medinalis (Guenee) and natural enemies in cultivated rice in Sambalpur, Odisha, India. Untreated rice plants served as control. An adjuvant, Tween 20 at 1%, was added with all the botanical extracts except the commercial formulation. Plant damage, insect population numbers, and yield were monitored during two consecutive wet seasons from 2022 to 2023. Mean rice yield was significantly higher in the A. indica and Acephate 95 SG treatments, i.e., 4.68 t/ha and 4.66 t/ha, respectively, compared to the control (2.27 t/ha) and were significantly at par with each other. The L. camara and A. indica treatments were effective against both the major lepidopteran rice insect pests. The highest cost-benefit ratio of (1:4.65) was obtained from the Acephate treatment and was closely followed by the A. indica treatment (1:3.74). All the studied botanicals had less impact on natural enemies than synthetic chemicals. Among these botanicals, the maximum mean population of predators (like spiders and carabid beetles) and parasitoids (like Tetrastichus schoenobii, Telenomus dignus, and Trichogramma japonicum) were observed in the A. indica and A. marmelos treatments. Although all the studied botanicals were effective against both the major insect pests in rice, the A. indica, A. marmelos, A. sativum, and L. camara treatments showed the most promising against rice insect pests, so they may be incorporated into integrated pest management of rice.

Despite increasing awareness of the threats they pose, exotic species continue to arrive in Antarctica with anthropogenic assistance, some of which inevitably have the potential to become aggressively invasive. Here, we provide the first report of the globally cosmopolitan species Psychoda albipennis (Diptera, Psychodidae; commonly known as moth flies) in Antarctica during the austral summer of 2021/2022, with the identification confirmed using traditional taxonomic and molecular approaches. The species was present in very large numbers and, although predominantly associated with the drainage and wastewater systems of Antarctic national operator stations in synanthropic situations, it was also present in surrounding natural habitats. While it is unclear if P. albipennis is capable of long-distance dispersal, adult psychodid flies are known to travel more than 90 m from their emergence sites, and up to 1.5 km with wind assistance. Thus, once established in the natural environment of King George Island there appears to be a high risk of the species rapidly becoming invasive. The introduction of non-native species such as P. albipennis can be a significant driver of future biodiversity change and loss, and seriously impact ecosystem health. In vulnerable low diversity ecosystems, such as in the terrestrial environments of Antarctica, non-native species can lead to step changes in ecological functions and interactions, displace native species and, potentially, lead to the extinction of native biota.

Soybean looper (SBL), Chrysodeixis includens (Walker 1858) (Lepidoptera: Noctuidae), is one of the most damaging insect pests of soybean, Glycine max (L.) Merr., in the mid-south region of the United States, and causes significant economic losses to cotton, sunflower, tomato, and tobacco crops in the United States, Brazil, and Argentina. Soybean production in the southern region accounted for 15.5% of the total production in the United States, and yield losses due to invertebrate pests were 5.8%, or 1.09 million metric ton, in 2022. As insecticide resistance of SBL continues to rise, the lack of alternate control strategies is a serious concern. Numerous studies have been reported on pest status, distribution, semiochemical-based attractant blends, pesticides and resistance mechanisms, host-plant resistance mechanisms, and molecular tools for controlling this pest in soybeans and other crops. However, there is no comprehensive review that summarizes and discusses these research on SBL and soybeans. The current management strategies for SBL remain heavily reliant on chemical insecticides and transgenic crops. In contrast, integrated pest management (IPM) strategies are needed to control the pest in an effective and environmentally friendly way. This review examines and synthesizes the literature on SBL as a significant pest of soybeans and other important crops, highlighting recent progress in ecological interactions, host plant defenses, and control strategies and identifying information gaps, thereby suggesting avenues for further research on this pest.

Twenty years ago, it was difficult to imagine the use of nucleic acids in plant protection as insecticides, but today it is a reality. New technologies often work inefficiently and are very expensive; however, qualitative changes occur during their development, making them more accessible and work effectively. Invented in 2008, contact oligonucleotide insecticides (olinscides, or DNA insecticides) based on the CUAD (contact unmodified antisense DNA) platform have been substantially improved and rethought. The main paradigm shift was demonstrating that unmodified antisense DNA can act as a contact insecticide. Key breakthroughs included identifying convenient target genes (rRNA genes), mechanism of action (DNA containment), and discovering insect pests (sternorrhynchans) with high susceptibility to olinscides. Today, the CUAD platform possesses impressive characteristics: low carbon footprint, high safety for non-target organisms, rapid biodegradability, and avoidance of target-site resistance. This next-generation class of insecticides creates opportunities for developing products tailored for specific insect pest populations. The 'genetic zipper' method, based on CUAD biotechnology, integrates molecular genetics, bioinformatics, and in vitro nucleic acid synthesis. It serves as a simple and flexible tool for DNA-programmable plant protection using unmodified antisense oligonucleotides targeting pest rRNAs. Aphids, key pests of important agricultural crops, can be effectively controlled by oligonucleotide insecticides at an affordable price, ensuring efficient control with minimal environmental risks. In this article, a low-dose concentration (0.1 ng/µL; 20 mg per hectare in 200 L of water) of the 11 nt long oligonucleotide insecticide Schip-11 shows effectiveness against the aphid Schizolachnus pineti, causing mortality rate of 76.06 ± 7.68 on the 12^th day (p<0.05). At a consumption rate of 200 L per hectare, the cost of the required oligonucleotide insecticide is about 0.5 USD/ha using liquid-phase DNA synthesis making them competitive in the market and very affordable for lab investigations. We also show that non-canonical base pairing G_olinscide: U_rRNA is well tolerated in aphids. Thus, non-canonical base-pairing should be considered not to harm non-target organisms and can be easily solved during the design of oligonucleotide insecticides. The 'genetic zipper' method, based on CUAD biotechnology, helps quickly create a plethora of efficient oligonucleotide pesticides against aphids and other pests. Already today, according to our estimations, the 'genetic zipper' is potentially capable of effectively controlling 10-15% of all insect pests using a simple and flexible algorithm.

The horizontal transmission of endosymbionts between hosts and parasitoids plays a crucial role in biological control, yet its mechanisms remain poorly understood. This study investigates the dynamics of horizontal transfer of Wolbachia (wCcep) from the rice moth, Corcyra cephalonica, to its parasitoid, Trichogramma chilonis. Through PCR detection and phylogenetic analysis, we demonstrated the presence of identical wCcep strains in both host and parasitoid populations, providing evidence for natural horizontal transmission. To investigate thoroughly, Wolbachia-free colonies were acquired through tetracycline treatment, and the initial density of wCcep in host eggs significantly influences transmission efficiency. High-density wCcep infections led to rapid transmission, with F1 parasitoid titers increasing by as much as 100-fold, while low-density infections exhibited more gradual increases. Additionally, without continuous exposure to infected hosts, wCcep density in T. chilonis diminished over generations. These findings enhance our understanding of Wolbachia's transfer dynamics and have important implications for developing effective and sustainable biological control strategies using parasitoid wasps, particularly in managing Wolbachia-related pest populations in agricultural systems.

Introduction: This study considers concepts and tools of landscape ecology and geographic information systems (GIS) to prioritize insect monitoring in large-scale crops, using the cotton agroecosystem of the Texas Gulf Coast and two plant bug species (Creontiades signatus Distant and Pseudatomoscelis seriatus (Reuter) [Hemiptera: Miridae]) as a case study. The two species differed in host plants and time span as cotton pests.

Methods: C. signatus and P. seriatus abundance in early growth of cotton were regressed on landscape metrics. Comparisons of three approaches to select landscape variables in stepwise multiple regressions were made across spatial scales and two weeks of insect data extracted from monitoring of 21 cotton fields, years 2010 through 2013.

Results and discussion: The spatial variation of plant bug abundance and the landscape features were substantial, aiding the regression approach. For full stepwise regression models using 18 landscape variables, regression model fit using C. signatus data was modestly better in week one of sampling when C. signatus adults and young nymphs were detected (R ² range of 0.56 to 0.82), as compared with model fit at week two (R ² range of 0.49 to 0.77). The smallest scale (2.5 km radius) models had the greatest number of variables selected and highest R ², while two broader scales (5 and 10 km) and truncating the models to three variables produced a narrower range of R ²s (0.49 to 0.62) and more consistent entry of variables. Wetland composition had a consistent positive association with C. signatus abundance, supporting its association with seepweeds which are common in coastal wetlands. When selected, the composition of cotton and grassland/shrubland/pasture also had a positive association with C. signatus abundance. Aggregation metrics were also relevant, but composition metrics in the models were arguably more easily utilized in prioritizing insect monitoring. In contrast, there were few significant regressions using P. seriatus data, possibly due to the widespread distribution of its weedy host plants and lower abundance. Overall, selected landscape features served as indicators of C. signatus infestation potential in cotton particularly grown near coastal wetlands, but landscape features were not useful for P. seriatus infestation potential in cotton.

Scarabaeoidea is a diverse and widely distributed insect group; many are agricultural pests including species within the genus Phyllophaga. Species diversity studies in this taxonomic group are done mainly using morphological identification. However, despite existing taxonomic keys for adults and larvae, identification may be difficult due to their complex morphology. Molecular taxonomy can increase the value and accuracy of morphological species identification of larvae and adults. To test this, larvae collected from soil close to maize plants were identified using molecular taxonomy, and compared with adults captured using light traps. The larvae (2021) and adults (2022) were sampled on maize at the same locations in central Mexico. Molecular identification was achieved using three regions within the Cytochrome oxidase gene (cox), two in the Cytochrome c oxidase subunit 1 (cox1), Cytochrome b (CytB) and 28S rDNA. Cox gene information was more useful than nuclear information (28S). Combined morphological and molecular taxonomy of adults distinguished between seven Phyllophaga species. Although two closely related species, P. polyphyla and P. ravida, were distinguished using cox gene information, greater resolution was obtained using CytB. All analyses identified cryptic species within P. vetula. Species found amongst sampled adults were similar to those found amongst larvae. However, the number of species was greater in adults than in larvae at the same locations. Larval information showed Phyllophaga community structure changed over time. Our findings will contribute to a better understanding of Phyllophaga's ecology in maize.

We present a short review of the biology, diagnostic characteristics, and invasiveness of the Oriental hornet, Vespa orientalis. We also performed an analysis of the shape of the forewings (geometric morphometrics) of different geographic groups along their native distribution and their potential geographical distribution using the MaxEnt entropy modeling. Our results show a wide potential expansion range of the species, including an increase in environmentally suitable areas in Europe, Asia, and Africa but more especially the Western Hemisphere, where the species was recently introduced. The geometric morphometric analysis of the forewings shows that there are three different morphogroups: one distributed along the Mediterranean coast of Europe and the Middle East (MEDI), another along the Arabian Peninsula and Western Asia but excluding the Mediterranean coast (MEAS), and one more in northern Africa north of the Sahara and south of the Mediterranean coast (AFRI), all of which show differences in their potential distribution as a result of the pressure from the different environments and which will also determine the capacity of the different morphogroups to successfully invade new habitats.