Environmental Entomology最新文献

One of the main challenges in improving agricultural productivity is the prevalence of pests and diseases, which are highly sensitive to extreme weather conditions. The interaction between weather patterns and pest infestations significantly affects crop yield. Traditional statistical methods often struggle to capture the complex temporal and geographical dynamics of these interactions. However, employing multivariate cointegration has proven valuable for estimating such interactions and quantifying the extent to which various environmental conditions influence pest populations. The study further investigated impulse response functions, which revealed substantial impacts of temperature and relative humidity on pest populations through unit standard deviation shocks to endogenous variables. Specifically, this research examined the dynamic causal relationships between major pest occurrences and environmental variables in 3 groundnut-growing states of India-Andhra Pradesh, Gujarat, and Tamil Nadu, using cointegration and Vector Error Correction Model techniques. The analysis incorporated key environmental variables, including temperature, relative humidity, and rainfall. Results from the Johansen test indicated a strong long-term equilibrium relationship between pest populations and climatic conditions, confirming the presence of at least one cointegrating vector at the 5% significance level. Granger causality tests further revealed that temperature and relative humidity had a unidirectional causal influence on the pest occurrence. Additionally, impulse response analysis further revealed that shocks to temperature and relative humidity produced significant and persistent effects on pest incidence over time.

Old World climbing fern, Lygodium microphyllum (Cav.) R. Br., is one of the worst invasive weeds of natural areas of southern and central Florida, United States. The climbing fern forms thick mats that shade native shrubs and trees. Old World climbing fern invades the southern peninsula of Florida, where cost-effective, sustainable control methods are needed. Here, we report the results of greenhouse studies that examined the performance of Lygomusotima stria Solis & Yen larvae, a potential biological control agent of L. microphyllum. We examined the impact of larval feeding on the target weed when grown at a range of fertilizer and herbivore levels. Furthermore, we applied these treatments to guide post-release mass rearing protocols. The results indicate that larvae had greater survival when fed plants at the highest fertilizer level. Two generations of feeding by L. stria larvae decreased rachis weights at the lowest fertilizer levels and fiddlehead numbers. At higher fertilizer conditions, the plants were able to tolerate L. stria herbivory, resulting in no significant changes in plant tissue allocations. The increased larval survival when fed plants grown at high fertilizer levels will benefit both laboratory and field mass production of agents. By impacting rachises and fiddleheads, these results suggest this insect will impede the ability of L. microphyllum to climb substrates, especially in lower resource conditions.

The rapid growth of the global population has led to an alarming increase in waste generation, with landfills continuing to serve as the primary waste management solution in many developing countries. This surge in solid waste accumulation is putting immense pressure on landfill capacities, underscoring the urgent need for innovative waste management strategies, especially in regions still heavily dependent on traditional systems. This study investigates the potential of black soldier fly larvae to process 3 distinct types of landfill waste: food waste, aged landfill waste, and municipal solid waste sludge. Neonate larvae (0-1-day-old) were applied to 2.5 ± 0.02 kg of waste to assess key performance metrics, including waste reduction (% dry matter), survival rate (%), bioconversion rate (% dry matter), and waste conversion efficiency (% dry matter). The results revealed that black soldier fly larvae effectively reduced waste by 41.6-55.8%. However, across all treatment groups, the larvae exhibited low efficiency in converting waste into biomass. Notably, while performance comparisons with the control feed (commercial chicken feed) yielded predominantly adverse outcomes, the fresh waste treatment showed a marginally positive impact on waste reduction. These findings highlight the potential of black soldier fly larvae in landfill waste management while also identifying significant limitations in bioconversion efficiency. To optimize the application of black soldier fly larvae in sustainable waste management practices, further research is warranted to explore innovative pretreatment methods and other factors that could enhance their efficacy in biomass production.

The parasitoid wasp Aphelinus asychis Walker (Hymenoptera: Aphelinidae) has been shown to effectively control parthenogenetic Acyrthosiphon pisum Harris (Hemiptera: Aphididae) populations. However, its effectiveness against the sexual generation of aphids remains unclear. Additionally, secondary symbionts in aphids, such as Hamiltonella defensa and Regiella insecticola (both Enterobacterales: Enterobacteriaceae), may influence parasitoid success. This study investigated the parasitism performances of A. asychis among third-instar oviparous female, male, and viviparous females of A. pisum, as well as the effects of aphid density, parasitoid density, and aphid symbiont infections on parasitoid emergence and aphid mortality. The results showed that A. asychis exhibited high parasitism performance on third-instar male aphids, with parasitoid emergence and host mortality that were significantly greater than in viviparous and oviparous females. Increasing aphid density initially enhanced parasitoid emergence per-female, but efficacy plateaued at higher aphid densities, likely due to superparasitism and larval competition. Moreover, higher parasitoid densities increased aphid mortality but reduced per-female parasitoid emergence. Symbiont infection significantly reduced parasitoid success. Aphids uninfected with symbionts exhibited the highest parasitoid emergence, followed by those infected singly with H. defensa. Aphids singly infected with R. insecticola or co-infected exhibited the lowest parasitoid emergence. No additive protective effect was detected in aphids co-infected with H. defensa and R. insecticola, potentially due to shared defense mechanisms, a lack of synergistic benefits between coexisting symbionts, or competitive interactions. Our findings highlight the need to integrate knowledge of aphid reproductive biology, parasitoid behavior, and symbiont-mediated defenses to optimize biological control strategies targeting A. pisum.

Heat waves, brief periods of unusually high temperatures, are increasing in frequency and intensity globally. Such extreme weather events can alter plant chemistry, disrupting species interactions that contribute to pest suppression or increase their performance. Yet, most heat wave studies focus on pairwise interactions, leaving us with a poor understanding of how complex agroecosystems respond to temperature extremes. We addressed this knowledge gap by simulating an experimental heat wave in the field on potato plants (Solanum tuberosum L.) and the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), in the presence or absence of their mutualistic microbial symbionts and another pest, the potato aphid (Macrosiphum euphorbiae (Thomas)). We assessed beetle performance alongside changes in volatile organic compounds (VOCs) and glycoalkaloids from host plants. Beetle performance declined in the absence of their microbial symbionts and under aphid competition, but this effect was reversed under heat wave conditions. These results corresponded with a downregulation in glycoalkaloids, suggesting that potato prioritizes heat stress response over herbivore attack by divesting resources from the production of defensive compounds. The heat wave strongly affected VOCs composition, reducing emissions of multiple compounds while increasing others, but these changes were not directly linked with CPB performance. Overall, our results demonstrate that heat wave effects on crop-pest dynamics are dependent on the agroecological context and mediated by specialized metabolites. Importantly, under dual herbivore pressure, potato crops appear to prioritize coping with heat over defending against pests, underscoring the urgent need for pest management strategies that account for extreme climate events.

Dung-breeding flies of pastured cattle have substantial economic impacts on livestock production. To prevent losses, many producers use insecticidal fly treatments which have off-target impacts on beneficial pasture insects such as coprophagous and predatory dung-inhabiting beetles. These insects suppress pasture pest fly populations either through resource competition or direct predation of fly eggs and larvae in the dung. Feed-through insecticides such as insect growth regulators (IGRs) are thought to have fewer harmful off-target impacts because they target immature fly stages in the dung. However, impacts on the larval development of dung beetles are not well understood. The aim of this study was to analyze dung beetle and pest fly populations on grazing beef farms using feed-through insecticides for pest fly management. Between May and September in 2022 and 2024, populations of horn flies, face flies, and stable flies were counted on cattle, and dung-inhabiting Coleoptera populations were surveyed on pastures. The abundance and diversity of dung beetles (Scarabaeidae: Onthophagus and Aphodius spp.) and the abundance of predatory dung insects (Hydrophilidae and Staphylinidae) were significantly lower on farms using feed-through insecticides compared to farms not treating. Horn fly populations rarely exceeded economic thresholds without the use of feed-through insecticides, implying treatment was unnecessary. Face fly populations mostly exceeded economic thresholds even on farms using feed-through insecticides-indicating treatments were not adequately controlling their populations. The use of feed-through insecticides over the whole season is therefore not an integrated approach to controlling flies on pastures and puts other beneficial organisms in the pasture agroecosystem at risk.

In the years immediately following its introduction in 1986, the Russian wheat aphid Diuraphis noxia (Kurdjumov) became a significant pest of wheat in the western United States. In recent years, however, there have been few reports of economically damaging populations and lower numbers of Russian wheat aphid collected in suction traps. Here, we present evidence that the existing natural enemy complex may significantly reduce Russian wheat aphid populations even if no single species can be shown to be highly effective. In this study, we used 3 exclusion cage treatments (fully caged, partially caged, and uncaged plots) to explore the effects of the existing natural enemy complex on Russian wheat aphid populations in winter wheat in 3 fields across a north-south gradient in eastern Colorado: Fort Collins (northeastern Colorado), Akron (eastern Colorado), and Lamar (southeastern Colorado). Natural enemies were collected and identified. Fewer aphids and symptomatic wheat tillers were found in the uncaged treatment and partially caged treatments than in the caged treatment, which excluded the possibility of natural enemy attack on aphids, suggesting that natural enemies were responsible for suppressing Russian aphid populations in the open cage treatments. Predators were collected on both early and later growth stages of wheat, whereas parasitoids were found only on the later growth stage. Together, these findings suggest that the natural enemy complex is responsible for reducing Russian wheat aphid abundance among different dryland agroecosystems and climatic conditions.

Eastern flower thrips (Frankliniella tritici, Fitch) and soybean thrips (Neohydatothrips variabilis, Beach) are vectors of soybean vein necrosis virus (SVNV) and have increased in importance since the detection of the SVNV in 2008 in Arkansas. Understanding the factors that influence the timing and extent of these insects' activity, along with their predators such as the insidious flower bug (Orius insidiosus, Say), could contribute to improved management. Here, we compiled monitoring data between 2020 and 2023 from the American Midwest Suction Trap Network and examined associations between the timing of early and late activity, cumulative activity density, weather, landscape composition, and host plant phenology. We found that the activity of Eastern flower thrips began earlier, and insidious flower bug activity occurred later when conditions were warmer. In contrast, the activity of soybean thrips began earlier when there was higher edge density in the landscape but was not coincident with the timing of soybean bloom, suggesting an important role for noncrop host plants in early activity of these insects. Despite becoming active later, soybean thrips had greater cumulative activity density where it was warmer, a discordance suggesting the importance of migration in their overall abundance. Suction trap captures might therefore reflect the influences of local conditions as well as migratory movements on soybean thrips activity. Soybean thrips and insidious flower bug cumulative activity densities were also found to be positively correlated, suggesting that insidious flower bugs may be opportunistically utilizing soybean thrips as prey. Continued regional monitoring of these insects could be used to improve vector management.

Ecological niche modelling provides a tool for making a priori predictions of habitat suitability for biological control agents. Current approaches may be limited by available data but improved by the incorporation of physiological data. Alligatorweed, Alternanthera philoxeroides (Mart.) Griseb. (Caryophyllales: Ameranthaceae), is controlled across much of its introduced range in the United States of America by the alligatorweed flea beetle, Agasicles hygrophila Selman and Vogt (Coleoptera: Chrysomelidae); however, insufficient control is observed at temperate latitudes. Investigations into alligatorweed thrips, Amynothrips andersoni O'Neill (Thysanoptera: Phlaeothripidae), indicate that they are more cold-tolerant with a broader predicted range. The upper limit of the chill injury zone (ULCIZ) and the sum of injurious temperatures (SIT) are measures that can be used to compare relative cold tolerance among biocontrol agents. Here we propose a method for integrating these parameters with weather data to predict overwintering mortality. The ULCIZ and SIT of Am. andersoni and Ag. hygrophila were experimentally determined, then habitat suitability for each species was modeled using the proposed method and 20 yr of weather data. ULCIZ was -2.94 and 4.52 °C, and SIT was 307.19 and 251.27 for Am. andersoni and Ag. hygrophila, respectively, indicating that Am. andersoni begins accumulating chill injury at a lower temperature than Ag. hygrophila and does so at a slower rate. Using this method, 91.8% of Al. philoxeroides's range in the USA was predicted to fall within highly or moderately suitable habitat for Am. andersoni, compared to 15.9% for Ag. hygrophila. Ranges predicted by the proposed method are similar to previous correlative ENMs.

This study evaluated the efficacy and shelf life of a locally developed viral prototype product based on Hyphantria cunea granulovirus (HycuGV-Hc1) for the control of the fall webworm (Hyphantria cunea Drury; Lepidoptera: Arctiidae), a polyphagous pest commonly observed in the Black Sea and Marmara regions of Turkey, under field conditions. The field trials were conducted in Trabzon, in the Eastern Black Sea Province, during 2022 and 2023. The viral formulation was tested on mulberry, hazelnut, and walnut host plants against Hyphantria cunea larvae at 2 × 108, 2 × 107, and 2 × 106 occlusion body (OB)/ml concentrations. AGREE 50 WG (Commercial Product), which contains 50% Bacillus thuringiensis as the active ingredient used in Turkey against H. cunea was used as a comparison. At the highest concentration, the mortality rates were recorded at 85.42%, 80.85%, and 79.59% for mulberry, hazelnut, and walnut plants, respectively. When comparing the control groups across different plants, the most damage was observed on the mulberry plant. Comparable efficacy was observed with the commercial B. thuringiensis pesticide. In the shelf-life study, formulations prepared for different periods (0, 6, and 12 mo) were found to have similar mortality effects. The local viral prototype product displayed significant potential for controlling Hyphantria cunea in the field condition at 7 d after application.