Insects最新文献

Stored-product mites are important pests of stored products, while their presence in storage and processing facilities has a significant effect on public health. On the other hand, inert materials are promising alternatives to conventional pesticides in stored product protection and have provided very good results against storage insects. These formulations can be applied either directly on the product or on surfaces, as dusts or as slurry formulations. In the current paper, we review the factors that affect the efficacy of inert dusts, emphasizing in diatomaceous earths, against stored-product mites. Hence, we address the different biotic and abiotic factors that affect the acaricidal effect of inert materials against different mite species, but also the complexity of such an application, that often arises from the simultaneous presence of plant-feeding mites with their mite predators. Finally, we provide some insights for further research directions.

Cadmium in agricultural soils has emerged as a substantial threat to crop health and yields through its bioaccumulation along the food chain, with further repercussions for the growth, development, and population dynamics of herbivorous insects. In this study, potted potato plants were treated with Cd²⁺ solutions at concentrations of 0 mg/kg, 30 mg/kg, 60 mg/kg, 90 mg/kg, and 120 mg/kg. Colorado potato beetles (Leptinotarsa decemlineata) were fed on potato leaves exposed to these varying concentrations of cadmium, and the effects on their growth and development were assessed. The results revealed that: 1. The developmental period, pupal stage, and pre-oviposition period of the first-instar larvae of L. decemlineata feeding on cadmium-contaminated leaves was significantly prolonged, while both the lifespan and fecundity were reduced. 2. Key population parameters, including the innate rate of increase (r), finite rate of increase (λ), net reproductive rate (R₀), and gross reproduction rate (GRR), were evidently lower in cadmium-exposed L. decemlineata, while the average generation time did not show a significant difference. 3. Cadmium exposure also resulted in a remarkable reduction in survival and reproductive rates at specific life stages, along with an increase in the incidence of deformations in newly emerged adults. These findings underscore the detrimental effects of cadmium on both crop health and pest populations. This study holds valuable implications for more effective implementation of pest control strategies in the future, offering robust scientific evidence to support the safeguarding of food security.

Earias insulana Boisd. (Lepidoptera: Nolidae) is a major pest of cotton and other crops in Egypt, and the widespread use of insecticides has led to resistance. This study evaluates, for the first time, the bioactivity of Croton tiglium (Malpighiales: Euphorbiaceae) oil and its nano-emulsion (CTNE) against 25 newly hatched larvae of E. insulana Boisd. We assessed their biological effects across different developmental stages and performed histological and ultrastructural examinations. Gas-liquid chromatography (GLC) identified several bioactive compounds in C. tiglium oil crushed dry seeds, including fatty acids, hydrocarbons, and sterols. CTNE showed excellent quality with a zeta potential of -17.7 mV, an average particle size of 54.28 nm, and spherical droplets of 42.42 nm in diameter. The LC₅₀ values for C. tiglium oil and CTNE were 9.02% and 2.70%, respectively. Both treatments significantly impacted the biological characteristics of E. insulana Boisd., including reduced larval and pupal weight, lower adult emergence, decreased fecundity, and increased mortality. Histologically, there was epithelial cell hypotrophy and detachment, while ultrastructural damage included chromatin condensation, nuclear envelope folding, and mitochondrial damage, indicating apoptotic degeneration. These findings suggest C. tiglium oil and CTNE as potential, safe alternatives to chemical insecticides.

In this paper, we present a review of stridulating species of aphids of the Macrosiphini genus Uroleucon (Hemiptera, Aphididae) and include 13 species. The most characteristic feature of the reviewed species is the presence of unusual aphids' peg-like sensilla distributed on the hind tibia, which are rubbed against the surface of the siphunculi. A new aphid species-Uroleucon remaudiereisp. nov., living on Asyneuma persicum and Michauxia laevigata (Campanulaceae) in Iran-is described and illustrated based on the apterous and alate viviparous females. The new species is differentiated from other morphologically similar congeners. An identification key for apterous viviparous females of all Uroleucon species living on Campanulaceae and sound-producing species of the genus Uroleucon are provided. Additionally, a scanning electron microscopy analysis of the apterous and alate viviparous females of this species was made to elucidate the features of the general morphology, antennal sensilla, and stridulatory apparatus for the first time.

Honey bees transform nectar into honey through a combination of physical and chemical processes, with the physical process primarily involving the evaporation of excess water to concentrate the nectar. However, the factors affecting evaporation efficiency, such as evaporation duration, cell type, and bee species, remain incompletely understood. This study aimed to examine how these factors affect nectar evaporation efficiency during honey production. We measured the sucrose content in solutions subjected to combined active and passive evaporation, as well as passive evaporation alone. The results showed that eastern honey bee (EHB; Apis cerana) colonies were more efficient at concentrating sucrose solutions in worker cells than in drone cells under both combined active and passive evaporation conditions, as well as passive evaporation alone. Conversely, western honey bee (WHB; Apis mellifera) colonies exhibited greater efficiency in drone cells. Additionally, EHB colonies were more effective than WHB colonies in converting sucrose into fructose and glucose. Under passive evaporation, EHB colonies required at least 48 h to significantly concentrate the sucrose solution, while WHB colonies achieved similar concentrations in just 24 h. Sucrose content increased with the duration of passive evaporation. These findings provide insights into how honey bee colonies can efficiently produce mature honey during periods of abundant nectar flow.

The nomenclatural and taxonomic issues regarding the thread-legged bug genera Pleias Kirkaldy, 1901 and Bagauda Bergroth, 1903 are reviewed, and Pleias is concluded to be the valid name of the genus. A comprehensive review of Pleias is conducted, resulting in 18 new combinations and two new synonymies [P. aelleni (Villiers, 1970) comb. n., P. atypica (Ghate, Boyane & Joshi, 2019) comb. n., P. avida (Bergroth, 1903) comb. n., P. brunnea (McAtee & Malloch, 1926) comb. n., P. cavernicola (Paiva, 1919) comb. n., P. creppei (Lhoste, 1939) comb. n. = Bagauda gilletti Miller, 1956 syn. n., P. ernstmayri (Kulkarni & Ghate, 2016) comb. n., P. furcosa (Ribes, 1987) comb. n., P. gigantea (Lhoste, 1939) comb. n., P. lucifuga (McAtee & Malloch, 1926) comb. n., P. monodi (Villiers, 1972) comb. n., P. similis (Wygodzinsky, 1966) comb. n., P. smithersi (Wygodzinsky, 1966) comb. n., P. splendens (Distant, 1906) comb. n., P. strinatii (Villiers, 1970) comb. n., P. tenebricola (Horváth, 1910) comb. n., P. wagneri (Villiers, 1949) comb. n. = B. eriksoni Miller, 1954 syn. n., and P. zetteli (Rédei, 2005) comb. n.]. The bibliographies, diagnosis, and known distribution records are presented for all described species, and three new species [P. fashengisp. n. (from Yunnan, China), P. serratasp. n. (from Sabah, Malaysia), and P. trimaculatasp. n. (from Sulawesi, Indonesia)] are described. The identification keys to the African and Asian species of Pleias are provided. The systematic relationships, distribution, and ecology of the genus are discussed.

Inwardly rectifying potassium (Kir) channels regulate essential physiological processes in insects and have been identified as potential targets for developing new insecticides. Flonicamid has been reported to inhibit Kir channels, disrupting the functions of salivary glands and renal tubules. However, the precise molecular target of flonicamid remains debated. It is unclear whether flonicamid directly targets Kir channels or acts on other sites involved in the activation of transient receptor potential vanilloid (TRPV) channels. In this study, we observed that flonicamid is more toxic to flies than its metabolite, flumetnicam. This higher toxicity is difficult to reconcile if nicotinamidase is the active target, as flonicamid does not inhibit nicotinamidase. An alternative explanation is that flonicamid and flumetnicam may have distinct targets or act on multiple targets. Furthermore, reducing the expression of three individual Kir genes in the salivary glands of D. melanogaster significantly decreased the flies' susceptibility to both flonicamid and flumetnicam. The double knockdown of Kir1 with Kir3 or Kir2 with Kir3 further reduced the flies' sensitivity to both compounds. These findings confirm the involvement of Kir channels in mediating the toxic effects of flonicamid on flies. Overall, this study offers new insights into the physiological roles of insect Kir channels and flonicamid toxicity.

Habitat fragmentation and land use changes threaten neotropical habitats and alter patterns of diversity at forest edges. Like other arthropod assemblages, neotropical fruit-feeding butterfly communities show strong vertical stratification within forests, with some recent work showing its potential role in speciation. At forest edges, species considered to be forest canopy specialists have been observed descending to the forest understory, with the similarity in light conditions between the canopy and understory strata at edges hypothesized to be responsible for this phenomenon. We conducted a study using standardized sampling to document and quantify this edge effect, characterize edge and forest strata, and estimate the relative contributions of temperature and light conditions to changes in nymphalid butterfly stratification at forest edges. We found strong evidence of an edge effect in these butterflies and confirmed strong differences in light and temperature, showing that the edge understory differs little from forest canopy conditions. Of 41 species common to both forests and edges, 28 shifted to have a lower canopy probability at the edge, and our model detected a decrease in canopy probability of 0.165. Furthermore, our analysis indicated the relative abundance of canopy taxa increased at the edge, and the tribes Haeterini and Morphini were especially sensitive to edge effects. However, the analyses here did not clearly implicate temperature or light magnitude in causing changes in neotropical nymphalid vertical stratification at forest edges. Instead, our results point to other mediator variables as being important for changes at tropical forest edges. From our data, edge-responsive species can be separated into two different categories, which likely relates to their resilience to anthropogenic disturbance. We also note that structural causal models have a potential place in future work on tropical conservation, given they can provide causal estimates with observational data.

Farmed edible insects are considered a potential resource to help address food security concerns toward the year 2050. The sustainability (e.g., lower environmental impact), nutritional (e.g., high-quality proteins, essential amino acids, fiber, unsaturated fats, vitamins, and minerals) and health (e.g., antioxidant, antihypertensive, anti-inflammatory, antimicrobial, and immunomodulatory) benefits are the main reasons for the rise in interest for insects as alternative protein sources for food and feed production. Thus, edible insects can address the future global protein demand of an ever-increasing world population. In this context, several aspects related to their sustainability have been explored and addressed from an environmental perspective. This review describes the rationale for using insects as alternative protein sources and provides a comprehensive viewpoint, integrating economic, environmental, and social aspects into their sustainability framework toward addressing food insecurity concerns. For example, edible insects offer a more sustainable protein source comparable to, or even better than, that of conventional livestock. Considering their sustainability advantages, insects are noted for their lower impact on natural resources (e.g., water and agrarian land) and lower greenhouse gas emissions (e.g., carbon dioxide and methane). From a socioeconomic point of view, edible insects have lower production costs compared to conventional animal protein sources because of their high feed efficiency conversion, rapid growth rate, and short life cycles. Currently, the market for edible, farmed insects is becoming a significant economic activity that not only meets the needs of industry and consumers but also supports the ability of future generations to maintain a secure and sustainable community.

The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and khapra beetle, Trogoderma granarium E. (Coleoptera: Dermestidae) are primary stored-grain insect pests. Differences in certain biological and physical parameters of both pest species and wheat genotypes were investigated under laboratory conditions. Zinc (Zn)-biofortified (Zincol-2016 and Akbar-2019) and conventional (Arooj-2022, Nawab-2021, Dilkash-2021, Bhakkar Star-2019) wheat genotypes were used in this study. Zn-biofortified genotypes outperformed the conventional ones, with significant differences observed in fecundity, percent adult emergence, total developmental duration, percent grain damage, and weight loss of both insect species. The results further revealed that the fecundity of R. dominica and T. granarium were lowest on Akbar-2019 in both the free-choice test (42.50 and 33.17) and no-choice test (35.50 and 32.50), respectively. Similarly, percent adult emergence of both insect species was also lowest on Akbar-2019 in both the free-choice test (69.78 and 70.28%) and no-choice test (67.38 and 70.71%). The total developmental period also showed significant variation among the tested genotypes. The longest developmental period was recorded in Akbar-2019, i.e., 44.33 and 58.83 days, for R. dominica and T. granarium, respectively. Similarly, percent grain damage (13.23 and 10.33%) and weight loss (3.62 and 2.12%) were found to be minimum in Akbar-2019 for both pest species, respectively. Additionally, a positive correlation was observed between grain moisture content and damage parameters, suggesting that the higher moisture content may aggravate the percent grain damage and weight loss. These findings indicate that the nutritional qualities of Zn-biofortified wheat genotypes negatively affected the development of both insect species; thus, it can be an efficacious approach not only for ensuring food security but also for protecting grains against storage pests.