Journal of economic entomology最新文献

Pollination by insects is vital for global agriculture, with honey bees (Apis mellifera L.) being the most important pollinators. Honey bees are exposed to numerous stressors, including disease, pesticides, and inadequate nutrition, resulting in significant colony losses. This study investigates the use of drone brood to mitigate these problems. Drone brood, which is normally discarded during varroa mite (Varroa destructor, Anderson and Trueman) management, is rich in proteins, fats, and essential minerals. We compared drone brood with an already suggested pollen supplement (Tenebrio [Tenebrio molitor L.] flour). The results indicate that drone brood flour is a viable source of proteins, fats, and minerals and is potentially antimicrobial due to its high content of elements with known antimicrobial properties. It meets the nutritional needs of honey bees while mitigating the effects of varroa mites. The use of drone brood flour can provide high-quality beeswax, surplus of pollen, and improve bee health, which promotes sustainable beekeeping.

The yellow mealworm, Tenebrio molitor L., is one of the most important industrialized insects worldwide. As a poikilotherm, T. molitor requires a temperature-regulated environment for its farming. Currently, the farming of T. molitor uses temperatures between 29 and 31°C determined to be optimal for maximizing growth. This study was aimed to test and determine optimal temperature for T. molitor impacting all stages including their development, reproduction, and fitness. Pupae of T. molitor were exposed to 8 different temperatures (18, 21, 24, 27, 30, 33, 36, and 39°C). Developmental rates (=1/d to develop) were calculated at 8 temperatures and fitted in a poikilotherm model to determine the temperature with the highest developmental rate (developmental maximum, To). The developmental maximum was 33°C and the thermal maximum (tm) (lethal temperature) was 39°C. The biological and demographic parameters of T. molitor were compared at 3 favorable temperatures below the To (31, 29, and 27°C) to determine the fitness of T. molitor populations. Fecundity and egg viability were the highest at 27°C (5.25 eggs/female/d and 73.99%, respectively) and the lowest at 31°C (1.55 eggs/female/d and 27.14%, respectively). The shortest larval development time was observed at 27°C and the longest at 31°C (142.81 and 161.97 d, respectively). The highest fitness was observed at 27°C with a population doubling time of 32.78 d compared to 40.58 and 239.4 d at 29 and 31°C, respectively. In conclusion, 27°C is closer to the optimal temperature for T. molitor productivity than 29°C, thus reducing its farming energy needs.

Insects provide important pollination services for cops. While land use intensification has resulted in steep declines of wild pollinator diversity across agricultural landscapes, releasing managed honeybees has been proposed as a countermeasure. However, it remains uncertain whether managed honeybees can close the pollination gap of sunflower (Helianthus annuus L. [Asterales: Asteraceae]) in areas lacking wild pollinators, and how the benefits of honeybees to sunflower production are modulated by soil nutrients. We investigated the effects of 3 pollination treatments (open, self and hand pollination) on sunflower yield parameters. We also estimated the pollination efficiency of managed honeybees (Apis mellifera L. [Hymenoptera: Apidae]), and analyzed the effects of honeybee visitation and soil nitrogen on sunflower yield parameters. Insect pollinators contributed 73% of seed set and 69% of the weight of filled seeds per head in the open pollination of sunflowers, but large pollination deficits still existed. Insect pollination may enhance sunflower yield by augmenting the number and weight of filled seeds per head, but not by altering the total number of seeds. Except for the total number of seeds per head, yield parameters increased significantly with the number of honeybee visits. Low nitrogen accelerated the positive effect of honeybee pollination on sunflowers, and alleviated the negative effect of distance of beehives on honeybee visitation rate. We conclude that managed honeybees could be used to pollinate sunflowers in areas with the shortage of wild pollinators, and sunflower production may benefit from shortening the distance of beehives and lowing of nitrogen fertilizer inputs.

The yellow mealworm, Tenebrio molitor, L., can be an important component of the circular economy because of its ability to transform a variety of agricultural wastes and byproducts into valuable livestock feed. Analysis of their ability to endure toxins coupled with their potential to transfer contaminants to higher trophic levels is not complete. Fumonisins, produced primarily by Fusarium verticillioides (Hypocreales: Netriaceae) (Sacc.) Nirenberg (1976), are mycotoxins likely to be encountered by T. molitor in corn and other grain byproducts. Tenebrio molitor larvae were reared on a simulated diet of corn and other grain byproducts treated with a range of maximum recommended fumonisin B1 levels for different livestock feeds. We observed that T. molitor were able to survive, grow, and reduce by excretion and metabolism their retained fumonisin B1 levels by up to 99.7% compared to the diet they consumed. Unknown metabolic processes were inferred from the significantly reduced content of fumonisin B1 in the frass (63.1% to 73.2%) as compared to the diet and by the first report of long-chain acylated fumonisin B1 derivatives in insect frass.

Invasive species pose a threat to ecosystems and humans worldwide, which is exacerbated by climate change, causing the expansion of species distributions. Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae) causes leaf drying and shedding in eucalyptus trees, forming blister-like galls that negatively impact the growth of the trees. Closterocerus chamaeleon (Hymenoptera: Eulophidae) is a recognized parasitoid of O. maskelli. This study used the MaxEnt and CLIMEX models to predict the potential distribution under current and future climate scenarios for O. maskelli and its natural enemy, C. chamaeleon. The MaxEnt model result indicated that isothermality was the most critical factor predicting the distribution of O. maskelli, while the mean temperature of the driest quarter was the most critical factor predicting the distribution of C. chamaeleon. Under current climate conditions, the CLIMEX model predicted a wider potential distribution for O. maskelli and a smaller distribution for C. chamaeleon than the MaxEnt model. MaxEnt and CLIMEX prediction results indicated that South America and Africa were suitable for O. maskelli and C. chamaeleon. The MaxEnt model indicated that under SSP245 climate conditions, the potentially suitable regions for these species expanded, while under the SSP126 climate scenario, the region contracted significantly. The CLIMEX model indicated that under the A1B and A2 climate scenarios, the marginally suitable areas increased, while the moderately and highly suitable areas decreased. This study provides a theoretical basis for creating early monitoring, quarantine, and control methods for invasive pests.

Exploring the effects of different solvent extracts from Lepista nuda [(Bull. ex Fr.) Cooke] on the lifespan and reproductive capacity of Drosophila melanogaster (Diptera: Drosophilidae), the extracts of the fruiting body and mycelium of L. nuda were prepared using water, 75% ethanol, and petroleum ether, and the active components were identified. These extracts were then incorporated into culture media and administered to D. melanogaster. The impact of the extracts from different solvents on the life span and fertility, and the contents of ecdysone (20E), juvenile hormone (JH), and vitellogenin (Vg), as well as the effects of autophagy gene, 20E synthesis gene Halloween, 20E receptor gene ECR, JH methyltransferase gene JHAMT and Vg gene Yolk1 transcripts were analyzed. The extracts from the fruiting body and mycelium of L. nuda can reduce lifespan, a phenomenon associated with the varied expression of 15 compounds across 6 distinct groups. The average survival time of female fruit flies was lower than that of the male fruit flies. Fertility had also been significantly reduced, indicating a positive correlation between lifespan and fertility. In addition, with the extension of cultivation time, the content of 20E, JH, and Vg, as well as the transcripts of Halloween, ECR, JHAMT, and Yolk1 in the L. nuda fruiting body extract treatment group, all significantly decreased. Among the 3 solvent extracts, phenylalanine, citric acid, quinic acid, and punicalagin in the L. nuda aqueous extract exhibit the most potent collective toxicity toward fruit flies. The insecticidal properties of these compounds function by modulating autophagy and the expression of insect hormones.

Tawny crazy ants (TCAs), Nylanderia fulva (Mayr) are an invasive species that develops extremely large populations that overrun landscapes. Control measures frequently rely on spraying contact insecticides, which often are inadequate. To provide insights for utilizing baits for their control, TCA foraging behavior was examined on liquid ant bait formulations that contained either fast-acting dinotefuran or slow-acting disodium octaborate tetrahydrate (DOT), and the impacts of these baits were assessed. Bayesian modeling of counts from time-lapse photography of TCA feeding on the baits and a control of sucrose solution in the field revealed strong evidence of similar foraging intensities between the control and the DOT bait and less foraging intensity on the dinotefuran bait. TCA abundance on the dinotefuran bait peaked within 8 h, then diminished to smaller feeding bouts over the 3-day study. In contrast, foraging on the DOT and control remained consistently high before bait depletion. The impact of the fast and slow-acting baits in field plots were based on TCA nest sizes and TCA abundance on sausage lures. Bayesian modeling predictions revealed nest sizes declined over the 2 months with bait present while the control had large nests. Abundance on the lures in the dinotefuran plots declined from the start of the study, while with the slow-acting DOT bait, declines in abundance were not lower than the control plot until 30 days after baiting was initiated. Further refinements in baiting with liquid baits containing fast and slow acting active ingredients may provide fast and sustained control of TCA.

Solenopsis invicta Buren (Hymenoptera: Formicidae), also known as the red imported fire ant (RIFA), is currently established in many Southern and Central Californian regions. RIFA can be managed using various insecticides, but in recent decades, granular baits have become a standard and effective management tool. To improve and maintain effective RIFA management programs, researchers and pest control experts need to perform careful population monitoring before and after treatments. Despite the availability of various RIFA monitoring methods, many are challenging to perform and are extremely time-consuming. Counting mounds is an easier-to-perform method but may not be reliable in certain places and for detecting low-density populations. Other methods of field sampling and laboratory counting can be cumbersome, destructive, and highly time-consuming. In this article, we are providing research data on a new, fast, and nondestructive field technique for RIFA monitoring using density (ants/ml) measurements. These measurements can be converted into counts and eventually to indices. On average, the density of RIFAs inside our measuring cylinder was 130.8 ± 2.3 ants/ml (Mean ± S.E.). A strong positive and statistically significant correlation was found between the volume of RIFA workers and the number of ants (r = 0.92, P < 0.001).

The solitary bee Osmia excavata (Hymenoptera: Megachilidae) is a key pollinator managed on a large scale. It has been widely used for commercial pollination of fruit trees, vegetables, and other crops with high efficiency in increasing the crop seeding rate, yield, and seed quality in Northern hemisphere. Here, a high-quality chromosome-level genome of O. excavata was generated using PacBio sequencing along with Hi-C technology. The genome size was 207.02 Mb, of which 90.25% of assembled sequences were anchored to 16 chromosomes with a contig N50 of 9,485 kb. Approximately 186.83 Mb, accounting for 27.93% of the genome, was identified as repeat sequences. The genome comprises 12,259 protein-coding genes, 96.24% of which were functionally annotated. Comparative genomics analysis suggested that the common ancestor of O. excavata and Osmia bicornis (Hymenoptera: Megachilidae) lived 8.54 million years ago. Furthermore, cytochrome P450 family might be involved in the responses of O. excavata to low-temperature stress. Taken together, the chromosome-level genome assembly of O. excavata provides in-depth knowledge and will be a helpful resource for the pollination biology research.

Point mutations in the acetylcholinesterase-1 gene (ace-1) have been associated with resistance to OPs in many insects. However, the presence and function of ace-1 mutations associated with OP resistance in Helicoverpa armigera (Lepidoptera: Noctuidae), a significant lepidopteran pest damaging a wide range of crops, remain largely unexplored. This study investigated resistance to the OP insecticide phoxim in 12 field populations of H. armigera from northern China in 2022, revealing low levels of resistance (2.5- to 6.7-fold). Using an amplicon sequencing approach, we screened for ace-1 mutations in 13,874 moths collected from 114 populations collected between 2006 and 2022. We found 3 amino acid substitutions (A201S, G227E, and F290V) potentially related to OP resistance. The mean frequencies of A201S, G227E, and F290V mutations were 0.0032, 0.0001, and 0.0001, respectively. To assess these mutations' role in OP resistance, we expressed wild-type and mutant AChE1 proteins in Sf9 cells. Biochemical characterization revealed a 3.1-fold and 3.3-fold increase in the I50 of chlorpyrifos-oxon for A201S and F290V mutants compared to the wild-type enzyme, correlating with a 2.9-fold and 2.7-fold decrease in the Ki value. No enzyme activity was observed in the G227E mutant, indicating that only A201S and F290V confer insensitivity to chlorpyrifos-oxon. Our study demonstrates that amplicon sequencing is an effective method for large-scale screening of resistance-associated point mutations in field populations of H. armigera and potentially other insect pests. It also identifies A201S and F290V in AChE1 as potential point mutations conferring OP resistance in field populations of H. armigera.