Entomological Research最新文献

The red flour beetle, Tribolium castaneum, is an agricultural and storage pest with a global distribution. Studies have shown that eucalyptol has strong contact toxicity against larvae of this beetle, whereas odorant binding proteins (OBPs) are known to contribute to larval defenses against this phytochemical toxin. However, the mechanisms underlying the protective effect of insect OBPs against eucalyptol remain unclear. Here, TcOBPC02 from T. castaneum was cloned and characterized. Gene expression profile analysis showed that TcOBPC02 is highly expressed at early larval and early pupal stages. Additionally, tissue expression profiling revealed that, in the adult, TcOBPC02 was most highly expressed in the head, followed by the epidermis, whereas in larvae, TcOBPC02 was mainly expressed in hemolymph and the epidermis. These developmental stages and tissues that exhibit high TcOBPC02 expression are closely related to the detoxification of heterologous substances. Furthermore, the mRNA level of TcOBPC02 was significantly increased after exposure to eucalyptol, whereas TcOBPC02-targeted RNA interference increased the susceptibility of T. castaneum to eucalyptol, indicating that TcOBPC02 participates in the tolerance of this beetle to eucalyptol. Additionally, recombinant TcOBPC02 was expressed in Escherichia coli and isolated, enabling a straightforward fluorescence competition binding assay. In combination, these results have demonstrated that TcOBPC02 is required for defenses against phytochemicals in T. castaneum. This study provides a theoretical basis for understanding the mechanisms underlying the degradation of exogenous toxicants in insects and adds to the repertoire of potential target genes for pest control.

The impact of climate change on insects, particularly pollinators such as bees, butterflies, moths and hoverflies, has been the focus of numerous studies. In this context, recognizing a gap in research on pollinators in the Republic of Korea, we employed species distribution models (SDMs) to assess the potential impacts of climate change on 206 species of pollinating insects in the Republic of Korea under two climate change scenarios: SSP245 and SSP585. Our results showed that under the SSP245 scenario, two bee species are projected to increase by 24.3% on average, whereas five species will decrease by 61.3%. For butterflies, 12 species will increase by 144.6%, whereas 35 species will decrease by 86.1%. For hoverflies, six species will increase by 75.7% and 13 species will decrease by 68.8%. For moths, 37 species will increase by 131% and 96 species will decrease by 90.8%. Under the worst-case climate change scenario (SSP585), one bee species is expected to see its distribution range increase by an average of 161%, whereas six other species might experience a reduction of 73.2% on average. For butterflies, 15 species are projected to expand their range by an average of 157%, whereas 32 species could face an average decrease of 89.7%. In the case of hoverflies, ten species are anticipated to grow their distribution range by 117.9% on average, whereas nine species might decrease by an average of 90.8%. Lastly, for moths, 38 species are expected to expand their range by an average of 199%, whereas 95 species could contract their range by an average of 87%.

Despite the medicinal benefits of Pueraria lobata (kudzu), it stands as an invasive species that disrupts forest ecosystems, prompting the exploration of natural predators for its control. This study presents the first comprehensive report on Lema (Lema) diversipes, Pic, 1921, a beetle species that uses kudzu as its host, with significant implications for forest ecosystem dynamics. Detailed morphological descriptions and illustrations of its larva stage are provided for the first time. Additionally, partial sequences of mitochondrial cytochrome c oxidase subunit I, a domestic distribution map, and biological notes are included.

Insect C-type lectins (CTLs) play a vital role in recognizing and binding pathogen-associated molecules, such as carbohydrate moieties, to initiate immune responses. Although the characteristics of Bombyx mori C-type lectin 21 (BmCTL21), named BmLBP, have been reported, its molecular mechanisms, including expression patterns during immune responses and recognition and binding behaviors, remain poorly understood. Therefore, this study aims to explore the molecular characterization of BmCTL21 in innate immune responses. The findings reveal that BmCTL21 is upregulated in the fat body and subsequently transported to hemocytes, where it binds to the surface of Gram-negative bacteria during microbial infection. Additionally, BmCTL21 RNAi treatment leads to a decline in BmCTL21 expression, which results in the suppression of phenoloxidase activity. Moreover, recombinant BmCTL21 was found to recognize carbohydrates, such as lipopolysaccharide, mannan and N-acetyl-d-glucosamine, in a Ca²⁺-independent manner, and binds to the cell walls of Gram-negative bacteria, Gram-positive bacteria and fungi. In summary, this study offers new insights into the molecular mechanisms and functional behaviors of BmCTL21 in the innate immune response of silkworms.

This study evaluates the effects of various artificial diets on the development of Zophobas atratus larvae. Artificial diets containing various concentrations of agar were also investigated for their ability to reduce death rates during the early stages of larval development. Our results indicated that larvae fed artificial diets experienced a slightly longer developmental period but achieved significantly higher weights. Notably, wheat bran + fish meal 6% resulted in the highest weight gain; however, wheat bran + fish meal 6%, wheat bran + fish meal 5% + ginseng leaf 1%, and wheat bran + fish meal 4% + ginseng leaf 2% yielded higher death rates. The diet with 4% agar resulted in the shortest developmental period, whereas that with 3% agar produced the highest weight gain. However, considering death rates, the diet with 2% agar provided the most balanced outcome across developmental time, weight gain, and survival, making it the most suitable diet for Z. atratus larvae. In conclusion, wheat bran + fish meal + agar 2% artificial diet is more suitable for Z. atratus larval development than wheat bran, leading to greater weight gain, shorter development periods, and higher adult emergence rates. Additionally, this diet showed the potential to reduce the dust issues and labor demands associated with wheat bran usage. Our findings suggest that wheat bran + fish meal + agar 2% could be an effective artificial diet for the optimal development of Z. atratus larvae.

This study explores the diversity and distribution of spider populations across urban and natural-semi natural habitats in Gongju-si, South Korea. This study aims to investigate the ecological dynamics of spider populations across different habitat types and assess their implications for urban planning, particularly in terms of maintaining biodiversity through habitat heterogeneity and informed urban development strategies. Employing methodologies such as sweeping, manual collection, and pit-fall traps, the research identifies 128 spider species and evaluates alpha and beta diversity, nestedness, and species interactions using advanced statistical and ecological tools. The findings indicate significant variations in spider diversity across different habitats, with urban areas exhibiting notable biodiversity despite human influences. Natural habitats, especially forests, demonstrate higher biodiversity and more intricate species interactions. Nestedness analysis reveals distinct community structures across habitats, while association rule learning highlights complex interspecies relationships. The study underscores the importance of maintaining habitat heterogeneity and incorporating ecological principles in urban planning to support biodiversity. It offers valuable insights into the roles of various habitats in ecological networks, emphasizing the necessity for balanced urban development and effective conservation strategies.

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a destructive pest of Zea mays (maize) and other agricultural crops. The synthetic insecticides predominantly used against this pest lead to pest resistance, environmental contamination and health hazards. This study evaluated nanoformulated aqueous extracts of some promising local plant species against third instar larvae of S. frugiperda under laboratory and field conditions. The initial screening bioassay showed highest larval mortality with a 20% extract of Nicotiana tabacum L. (66.67%), followed by Azadirachta indica A. Juss. (53.33%), Withania somnifera L. (46.67%), Melia azedarach L. (40%) and Dodonaea viscosa Jacq. (33.33%). The two most effective plant extracts (A. indica and N. tabacum) were further nanoformulated with silver nitrate (AgNO₃) and bioassayed against S. frugiperda larvae using different concentrations. The results showed that these nanoformulated extracts caused significant larval mortality, with LC₅₀ (lethal concentration that kills 50% of the population) and LT₅₀ (lethal time to kill 50% of the population) values of 37.36 and 28.21% at 72 h, and 52.19 and 33.25 h at 80% concentration, respectively. Field experiments on Zea mays L. (maize) plants showed maximum larval reduction by nanoformulated A. indica extract (48%), followed by N. tabacum extract (36%), whereas 80% and 20% larval reduction was noted for the positive (SuperLock®, emamectin benzoate and tebufenozide) and the negative (water) controls, respectively. Furthermore, characterization of both silver nanoparticles-based plant extract formulations was performed using ultraviolet–visible (UV–vis) spectroscopy, Raman spectroscopy and scanning electron microscopy (SEM) techniques, which confirmed the formation of silver nanoparticles. It is concluded that nanoformulated plant extracts can be an effective alternative to synthetic pesticides in combatting S. frugiperda and other lepidopteran pests.

Euphorbia L. includes 2055 species with native range of this genus being cosmopolitan. In the present study, we assessed pollen morphology of 18 species of this genus occurring mostly in northern Pakistan. Pollen morphology of Euphorbia species is poorly investigated for its taxonomic significance. Here, we examined quantitative characters, including polar diameter, equatorial diameter, P/E ratio. Exine thickness, colpi length, and width were also examined. Among the qualitative characters, pollen shape, type, exine sculpturing, and aperture features were determined. The main aim of this study is to determine and investigate the foraging behavior of the honeybees that interact with Euphorbia species. The current finding will be helpful in melissopalynological analysis for developing beekeeping practices and can be used in the authentication of honey. Pollen quantitative traits applied through a multivariate analysis and diverse sampling also improve botanical and geographical characterization of a particular region. In addition, it is concluded that some palynomorphs of Euphorbia species may contain secondary compounds and can promote signs of toxicity in honeybees. However, the beekeepers wrongly correlate the fact that milky latex from Euphorbia taxa has burning and skin irritation effects on other animals, particularly humans, with honeybee deaths, which might be due to other factors. Our observations indicate with the sense that actual forage plants may not poison their pollinators and honeybees might occasionally be dead due to unidentified factors. We have suggested that beekeepers should attempt to identify the root causes for occasional bee deaths in the area.

The green peach aphid Myzus persicae Sülzer is a major insect pest of cruciferous plants, including vegetables such as Chinese cabbage. The objective of the present study was to determine the effects of sublethal afidopyropen and spirotetramat concentrations on the survival and reproduction of M. persicae. In addition, we used an electrical penetration graph (EPG) to study the feeding behavior of M. persicae on Chinese cabbage leaves treated with various concentrations of afidopyropen, spirotetramat and sulfoxaflor. The results showed that sublethal concentrations (LC₁₀ and LC₃₀) of afidopyropen and spirotetramat significantly decreased adult longevity and fecundity. However, sulfoxaflor had no significant effects. Several population parameters, including the net reproductive rate (R₀), intrinsic rate of increase (r_m), mean generation time (T), finite rate of increase (λ), and doubling time (DT), were significantly decreased only at the LC₃₀ of spirotetramat. According to the EPG feeding behavior analyses, when all three insecticides were applied at LC₃₀, the nonpenetration (NP) waveform significantly increased. The above results can be used as basic data for the well-planned use of insecticides.

Many types of livestock waste can be treated with insect larvae; however, in-depth research on the decomposition ability of Protaetia brevitarsis seulensis (PBS) larvae and the characteristics of manure after treatment with PBS is extremely limited. Therefore, this study examined the decomposition ability and survival rates of different instars of PBS larvae and their effects on the characteristics and pathogen counts of pig manure. Two treatments were designed: 1 kg of second instar or third instar PBS larvae per 10 kg of pig manure. Pig manure did not affect the decomposing capacity and survival rates of the two PBS larval instar groups (P > 0.05). However, the decomposition abilities of the different PBS larval instar groups on days 2, 7 and 8 significantly differed (P < 0.05). Over time, the changes observed in pH, moisture, total nitrogen, acid detergent fiber (ADF), neutral detergent fiber (NDF) and hemicelluloses did not significantly differ (P > 0.05) between treatments using second or third instar PBS larvae. On day 15, both total nitrogen and NDF significantly differed (P < 0.05) between the two treatment groups. During the experimental period, no significant (P > 0.05) change in Escherichia coli or Salmonella counts was observed in pig manure treated with different PBS larval instars. Our findings suggest that the decomposition abilities and survival rates of larvae and pig manure characteristics and pathogen counts do not differ for different PBS larval instar stages.