Entomological Research最新文献

Aedes aegypti is a mosquito species known for transmitting several diseases, with dengue fever being of utmost importance. Controlling the spread of dengue fever remains a significant global health challenge. Other diseases transmitted by Ae. aegypti include Zika virus, chikungunya, and yellow fever. Padina boryana algae were collected from the Red Sea coast south of Jeddah to evaluate the effectiveness of its alcoholic and aqueous extracts against Ae. aegypti mosquito larvae. The algae sample was washed, dried in the shade, processed, and subjected to aqueous and alcohol extraction using a rotary evaporator. The resulting extracts were tested for their larvicidal activity against Ae. aegypti mosquito larvae using standard bioassay techniques. The larval mortality rates were recorded, and the lethal concentration (LC₅₀ and LC₉₀) values were calculated.

The results revealed that both the aqueous and alcoholic extracts of P. boryana algae exhibited significant larvicidal activity against Ae. aegypti mosquito larvae. However, the alcoholic formulation demonstrated higher efficacy compared to the aqueous formulation. The LC₅₀ values for the alcoholic and aqueous extracts were 194.8 and 195.7 ppm, respectively. The LC₉₀ values for both extracts were 653.1 and 656.7 ppm, respectively. This indicates the effectiveness of Padina extracts as an effective pesticide against the larvae of the Ae. aegypti mosquito. Overall, the alcohol extract showed promising efficacy, indicating its potential as a significant component in developing effective mosquito control strategies.

Multiple physiological processes are involved in the interactions between the herbivore Dioryctria abietella and Pinaceae plants, with a key adaptation being the metabolic detoxification of host plant defensive substances. Moreover, the synthetic insecticides applied to control this coneworm are also shaping genes related to detoxification, such as the uridine diphosphate (UDP) glycosyltransferase (UGT) genes. Yet, the molecular mechanisms underpinning the resistance of D. abietella to toxic compounds remain unknown. In this study, we present an important UGT gene family involved in the detoxification mechanisms of D. abietella. Combining bioinformatic and transcriptomic approaches, a total of 37 UGT-coding genes were identified from the transcriptome of D. abietella, with 20 full-length sequences that shared high homology with UGTs found in other pyralid moths. These DabiUGTs were phylogenetically clustered into 12 subfamilies, with the three small clusters in the UGT33 and UGT40 clades mainly contributing to the size of the UGT gene repertoire in D. abietella. Expression profiles obtained from RNA sequencing (RNA-Seq), reverse transcription PCR (RT-PCR) and quantitative real-time PCR (qPCR) revealed that over half of DabiUGTs had a broad tissue expression profile, with 28, 28, 31 and 35 genes detected separately in antennae, legs, abdomens and reproductive tissues. Notably, DabiUGT20, DabiUGT25, DabiUGT28 and DabiUGT34 were all significantly enriched in the antennae. Several DabiUGTs had significant expression levels in reproductive tissues, including DabiUGT6, DabiUGT9, DabiUGT24, DabiUGT26 and DabiUGT32 in female accessory glands, DabiUGT15 in male accessory glands and DabiUGT25 in male testes. Altogether, our results identify candidate DabiUGTs for mediating olfaction and reproduction in D. abietella, warranting further investigation into the roles of DabiUGTs in pesticide resistance, odorant detection and reproduction.

Bioeconomy would be a beneficial solution for funding through the rational use of finances and human resources in order to achieve better productivity and fruitfulness of mosquito control programs. Synthetic insecticides are widely used to repress mosquitoes. However, it instigates problems such as insecticide resistance among mosquitoes such as developing resistance, bio-accumulation, and ecosystem destabilization. Natural plant-based products are a healthy alternative to use as mosquito larvicides. The country has to spend a considerable cost for buying synthetic insecticides too. Therefore, the present study was undertaken to evaluate larvicidal efficacy of Garcinia zeylanica, Garcinia quaesita, and Coleus hadiensis against Aedes aegypti mosquito larvae. Fresh leaves of plants were collected, and the aqueous crude extract was prepared. Phytochemicals were extracted using refluxing technique. A concentration series of crude extract of leaves were prepared separately from 20 to 100 mg/L. Batches of each containing 100 third instar larvae of Ae. aegypti were used for larval bioassays. Ae. aegypti mosquito larvae were evaluated in accordance with the guidelines of World Health Organization. The experimental setup was repeated four times at each concentration. Probit analysis was used to evaluate the relationship of mortality with the concentration of aqueous crude extract. The G. zeylanica and G. quaesita leaf extracts showed a dose-dependent effect against Ae. aegypti larvae after the 24 and 48 h exposure period. Interestingly, C. hadiensis did not show any dose-dependent effect against A. aegypti mosquito larvae. The percentage mortality rates have shown a significant variance among different concentrations (P = 0.000). The recorded LC₅₀ and LC₉₀ for aqueous crude extract of G. zeylanica were 27.167 and 52.861 g/L, respectively, and LC₅₀ and LC₉₀ for aqueous crude extract of G. quaesita were 36.841 and 76.036 g/L, respectively, after 24 h of exposure period. The G. zeylanica and G. quaesita plant's high larvicidal activity is supported by the presence of phytochemicals such as saponins, steroids, flavonoids, and phenol, which showed combination effects in terms of larvicidal action to mosquito larvae. Hence, there is a potential of G. zeylanica and G. quaesita aqueous leaf extracts as a key source for the development of an environment-friendly plant-based larvicide against Ae. aegypti. Hence, this warrants vector control entities to re-think “biological wealth for economic prosperity” with environmentally friendly country-wide control approaches for medically important disease vectors.

Nilaparvata lugens, the brown planthopper (BPH), is a serious pest species. BPHs cause significant damage to rice plants in Korea as well as other countries in East and Southeast Asia. As BPHs cannot survive winter in Korea, they annually migrate into Korea from foreign countries. The BPHs found in Korea are believed to originate from China, but most BPHs in China are also known to originate from Southeast Asia. To understand the origin of Korean BPHs, we conducted a genotyping-by-sequencing (GBS) study. We sampled BPHs from five locations in Korea and five countries in Southeast Asia and analyzed the GBS and sequencing results using various methods based on the f statistics and admixture graph analyses. We confirmed that the domestic BPHs shared a greater genetic drift than the BPHs from Southeast Asian populations over several years, implying that a continuous genetic substratum of Korea exists. This genetic substratum is genetically closer to BPHs from the southern part (Thailand and Cambodia) of Southeast Asia than to BPHs from the northern part (Bhutan, Myanmar and Laos) of Southeast Asia. In addition, direct gene flows from Southeast Asia seem possible, so Korea is considered a hotspot where diverse BPH populations mix. Therefore, the origin of Korean BPHs extends beyond China and as far as southern Southeast Asia. This result will help to understand and control the population dynamics of the Korean BPH population.

Traditional pesticide formulations have some shortcomings, including limited efficacy and the usage of huge amounts of insecticide, which has a negative impact on the environment. Using nano-pesticide formulations reduces the amount of pesticide applied, minimizing pest control expenses and environmental contamination. As a result, this study was conducted to develop a microemulsion formulation containing emamectin benzoate or beta-cyfluthrin with improved morphology, droplet size, emulsion stability, and persistence of foam. Moreover to assess the efficacy of the developed microemulsion in comparison to the convention alone against the Egyptian cotton leaf worm, Spodoptera littoralis (Boisd.) under both laboratory and field conditions. The results showed that the optimum conditions for emamectin benzoate microemulsion was 2% active ingredient, 5% (w/w) ethyl acetate, and DMF (3:2), 3.5% (w/w) Geronol ff4 and Etocas 35 (6:1), 5% (w/w) ethanol, and 86.5% (w/w) water, while for beta-cyfluthrin, a 5.0% active ingredient, 15% (w/w) Solvesso 100 and ethyl acetate (2:1), 7.0% (w/w) Geronol ff4 and Etocas 35 (6:1), 10% (w/w) ethanol, and 68% (w/w) water. Under laboratory conditions, emamectin benzoate was more toxic than beta-cyfluthrin to Spodoptera littoralis second and fourth instar larvae. Emamectin benzoate was more effective that beta-cyfluthrin against Spodoptera littoralis in the field, whether as a microemulsion or a commercial product. Thus, microemulsions of tested insecticides with better formulation qualities may be more effective than traditional ones in controlling cotton leaf worm.

Park H-J, Kwon M-J, Lee GW, Cho YH (2024) Gamma ray-irradiated fibroin protein from B. mori protects against TNF-α-induced oxidative stress and inflammation in human skin keratinocytes through NF-κB and Nrf2 signaling pathways. Entomological Research. 54: e12719.

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Functional diversity research enhances our understanding of ecosystems and both their functioning and their responses to environmental variations. This study investigated the biological trait responses of benthic invertebrate communities to various environmental conditions in estuarine habitats. We analyzed benthic macroinvertebrate communities in freshwater and estuarine environments to compare their characteristics between estuary sites with and without artificial barriers. Moreover, we combined taxonomic analyses (species richness, abundance, and four community indices) with functional diversity indices and biological trait analyses. The major results are as follows: (i) the most important environmental factors shaping species distribution in estuarine habitats were salinity and electrical conductivity; (ii) comparing functional diversity indices, tidal estuaries revealed that seawater intrusion induced changes in species distribution and the dispersion of benthic macroinvertebrates; (iii) the presence or absence of artificial barriers in estuaries affected biological traits owing to the influence of specific functional strategies of certain species. Consequently, the presence or absence of artificial barriers in estuaries can lead to significant changes in habitat connectivity and functional diversity related to ecosystem functions. These findings indicate that the presence of artificial barriers can significantly influence the ecological dynamics of estuarine ecosystems, thereby affecting species distribution, functional diversity and habitat connectivity. Understanding these effects contributes to a more comprehensive understanding of ecosystem functionings, as it complements existing taxonomic findings and integrates information about the functional aspects of diverse ecosystems.

This study was designed to explore differences in the competitive effects of wandering spiders under different cicada–spider ratios in tea plantations, and to provide a basis for the use of predatory wandering spiders for rational biological control. The population dynamics of Empoasca onukii and its natural enemies, the wandering spiders, were investigated in plantations of six tea cultivars, namely Anjibaicha, Huangshandayezhong, Longjing 43, Nongkangzao, Pingyangtezao and Wuniuzao, on the peak day of E. onukii emergence. Competition among wandering spiders under different cicada–spider ratios was analyzed using the gray correlation method and the competition coefficient method, and the results were then combined to derive a competition intensity index, which was then used to verify the accuracy of the results obtained. The results showed that the competition coefficients and competition intensity indices for low cicada–spider ratios were greater than those for high cicada–spider ratios on the peak day of E. onukii feeding, the differences between the two were significant at the t_0.20 level, and the most competitive wandering spiders at low and high ratios were Clubiona japonicola and Clubiona reichlini, respectively, indicating that the cicada–spider ratio had some influence on the competitive effect of the wandering spiders. The results provide a scientific basis for the study of competition between species of wandering spiders and the utilization of competitive wandering spiders against E. onukii for the protection of tea crops.

Deficiency of vitamin D3 has been found to be associated with an increased risk of developing some common diseases and death. However, the exact effect of vitamin D3 intake along with a high-protein diet and its optimal intake is unclear. The purpose of this work is to evaluate the beneficial effects of vitamin D3 on longevity using the Drosophila model. Vitamin D3 did extend lifespan on a high-protein diet, but above a certain concentration, it had the opposite effect in males. Our data suggest that the effect of vitamin D3 on longevity is diet-dependent and concentration-dependent.

Waste treatment using black soldier fly (BSF; Hermetia illucens L.) larvae is an emerging technology that reduces livestock manure disposal. This study aimed to evaluate the effect of different growth stage BSF larvae on the decomposition potential (Experiment 1) and characteristics (Experiment 2) of pig manure. BSF larval instars were randomly divided in three groups according to their developmental stage, with three replicates per group, using a randomized block design. Each treatment group consisted of 1 kg of 2nd, 3rd, or 4th instar BSF larvae added in 10 kg of pig manure (Group 1, 2, or 3, respectively). In Experiment 1, 2nd and 3rd instar BSF larvae treatments resulted in greater decomposition levels of pig manure compared with 4th instar BSF larvae groups. In Experiment 2, BSF larvae improved the nutrient content of manure, leading to an increase in the total nitrogen levels and a decrease in total carbon content and C:N ratio, rendering it suitable for use as an organic fertilizer. In addition, the increased N levels of treated BSF manure were not related to lower pH levels. BSF larvae can greatly reduce ADF and NDF pig manure contents as a result of the larvae's waste reduction potential. Overall, BSF 3rd instar larvae have proven to be a useful tool for the sustainable management of pig manure by strongly increasing its decomposition ability and can be an organic fertilizer for agricultural purposes that reduce ADF and NDF contents through composting.