Insects最新文献

Thirty-five genera and one hundred and two species of the tortricid tribe Olethreutini documented from Taiwan are listed, two genera and six species of which are newly recorded for China and two genera and eighteen species of which are newly recorded for Taiwan. Nine species are recorded in the mainland of China for the first time, which were endemic to Taiwan before this study. The local monographs of China and references are summarized with the examined specimens. The synonymies and geographic distribution in China are provided for each species, and a list of examined specimens is provided when applicable.

The development of reuse processes for plant by-products for both animal and human food offers numerous possibilities for quality-of-life improvements that align with a circular economy model. For this reason, we divided this study into two experiments. First, we designed a combined treatment consisting of laccase, ultrasound, and ascorbic acid to hydrolyze rice straw plant fibers and used the resulting feed as the basis for T. molitor diets. Second, we formulated diets with different inclusion levels (0%, 25%, 50%, 75%, and 100%) of rice straw and treated rice straw to assess their impact on larvae growth and diet digestibility. For each treatment, six replicates were employed: four for the growth-performance-digestibility trial and two for complementary uric acid determination tests. The combined laccase enzyme, ultrasound, and ascorbic acid treatment hydrolyzed 13.2% of the vegetable fibers. The diets containing treated rice straw resulted in higher larvae weight and a better feed conversion ratio; however, reaching 100% by-product inclusion values led to similar results between both diets. In conclusion, these treatments improve the potential of low-nutritional-value vegetable by-products as part of a T. molitor diet, opening the possibility of new methodologies for the use of recalcitrant vegetable by-products for insect rearing.

The insect gut harbors a diverse array of functional microorganisms that warrant further exploration and utilization. However, there is currently a paucity of research reports on the discovery of protease-producing microorganisms with industrial application value in the gut. Here, we employed microbial culturing to screen and identify the protease-producing microorganisms in the gut extract of Gryllotalpa orientalis. Based on morphological, physiological, and biochemical characterization, 16S rRNA sequencing, as well as ANI and dDDH values of whole genome, the protease-producing strains isolated from the insect gut were identified as Priestia aryahattai DBM-1 and DX-4, P. megaterium DX-3, and Serratia surfactantfaciens DBM-5. According to whole-genome analysis, strain DBM-5, which exhibited the highest enzyme activity, possesses abundant membrane transport genes and carbohydrate metabolism enzymes. In contrast, strains DX-3 and DX-4 not only have the ability to hydrolyze proteins but also demonstrate the capability to hydrolyze plant materials. Furthermore, strains that are closely related tend to have similar metabolic product gene clusters in their genomes. The screening and identification of protease resources are essential for the subsequent development and utilization of gut functional microorganisms and genetic resources in insects.

Seventy-five samples were collected from 15 beehives in the central highlands of Ecuador (Tungurahua-Chimborazo) to assess Africanization in managed bee populations using wing geometric morphometric and mitochondrial DNA analyses. The results indicated that when grouping the apiaries based on altitudinal floors into 2600-2800, 2801-3000, and 3001-3274 m above sea level, differences (p < 0.001) were observed. The morphotypes were similar in the first two floors, but the third indicated that altitude plays a crucial role in the differentiation of populations. When comparing with the pure subspecies, we found differences (p < 0.001); the nearest Mahalanobis distance was for Apis mellifera scutellata (D2 = 3.51), with 95.8% Africanization via father in the area. The maternal origin of all patterns belonged to lineage A (A. m. scutellata), with seven haplotypes. The most frequent haplotypes were A26 and A1; however, the A1q haplotype was not detected at the national level or in nearby countries. The identified haplotypes do not coincide with A4, which is predominant in South Africa and Brazil. The results indicate a double origin due to their presence in North Africa and the Iberian Peninsula. The formation of specific morphological groups within ecoregions is suggested.

Background: Food security is an increasingly pressing global issue, and by 2050, food production will not be sufficient to feed the growing population. Part of global food insecurity can be attributed to post-harvest losses, including quantity and quality losses caused by stored-product pests like insects. It is thus timely to find management strategies to mitigate these losses and counteract food insecurity. The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), a global stored-product pest with a wide range of food sources, was used in this study to assess repellency to a selection of essential oils.

Methods: Multiple behaviorally relevant methods were used to determine the efficacy of the essential oils in assays to pinpoint the most promising repellents. Experiments were used to assess individual and group behaviors with or without airflow and examined the behavioral variation in distance moved and the time spent away from the oil.

Results: It was found that exposure to essential oils and conditions of experimentation considerably influenced T. castaneum's behavioral response, but a clear candidate for repellency could not be chosen based on the collected data.

Conclusions: Follow-up research is needed to pinpoint repellents for integrated pest management practices to protect grains from stored-product pests and to justify their use in and around commodities.

The genus Laelius from China is revised for the first time and six species are recognized, including one new species as well as three new records. The new species, Laelius longus sp. nov., which is supported by both morphological and molecular analyses, is described and illustrated. Three new records, L. naniwaensis, L. nigrofemoratus, and L. yamatonis, are illustrated. A key to the Chinese species of Laelius is provided.

Pyrops candelaria is one of the common pests of fruit trees, but the research on the pathogenic microorganisms it may carry is very limited. Therefore, it is essential to reveal the pathogenic microbes it carries and their potential hazards. This study found a new virus from the transcriptome of P. candelaria, which was first reported in P. candelaria and named PyCaV (Pyrops candelaria associated virus). RACE and bioinformatics assay revealed that the full length of PyCaV is 10,855 bp with the polyA tail, containing a single open-reading frame (ORF) encoding a polyprotein consisting of 3171 amino acid (aa). The virus has a typical iflavirus structure, including two rhv domains, an RNA helicase domain (HEL), a 3C cysteine protease domain (Pro), and an RNA-dependent RNA polymerase domain (RdRp). Further phylogenetic analysis revealed that this virus belongs to family Iflaviridae and sequence alignments analysis suggested PyCaV is a new member in an unassigned genus of family Iflaviridae. Further in-depth analysis of the virus infection showed that PyCaV is distributed throughout the whole P. candelaria, including its head, chest, and abdomen, but more PyCaV was identified in the chest. The distribution of PyCaV in different parts of P. candelaria was further explored, which showed that more PyCaV was detected in its piercing-sucking mouthparts and chest viscera. Statistical analysis showed that the PyCaV infection was affected by time and location.

Cowpea mild mottle virus (CPMMV, genus Carlavirus, family Betaflexividae) is an economically important virus infecting soybeans in Brazil, where it was initially identified in 1983. CPMMV is transmitted by the whitefly, Bemisia tabaci, and occasionally by seeds. Over the last three decades, the most invasive B. tabaci Middle East-Asia Minor 1 (MEAM1), and lately the Mediterranean (MED) cryptic species, have replaced the indigenous species in Brazil, with MEAM1 being predominant. In this study, we investigated the transmission properties of CPMMV by MEAM1 and MED, and their distribution in major soybean-growing areas in São Paulo State. Our results from transmission assays with a single insect revealed that MED is a more efficient vector compared to MEAM1, transmitting the virus within a two-minute inoculation access period. B. tabaci MEAM1 is still the predominant whitefly species in São Paulo State, but MED was also identified in different places, mainly in mixed infestations with MEAM1. Some areas transitioned to a predominance of MED over the three years, while others, where MED had previously been detected, showed a reduction in the insects during the same period. Understanding the transmission dynamics of CPMMV and the distribution of its vectors is crucial for implementing effective management strategies to control the virus spread and protect soybean crops. Further research into the mechanisms driving the shifts in whitefly species dominance and CPMMV distribution will be essential for sustaining soybean production in Brazil.

The Colorado potato beetle (Leptinotarsa decemlineata) is a major pest of potato crops. While Knickkopf (Knk) genes are essential for insect cuticle formation, their roles in pests like L. decemlineata remain unclear. This study aims to identify and characterize Knk genes in L. decemlineata and explore their functions in larval development and cuticle integrity. We used genomic and transcriptomic databases to identify LdKnk-family genes, validated through RT-PCR and RACE. Gene expression was analyzed at various developmental stages and tissues using qRT-PCR. RNA interference (RNAi) and Transmission electron microscopy (TEM) were applied to determine the functional roles of these genes. Four LdKnk-family genes were identified. Spatio-temporal expression analysis indicated significant gene expression during larval molting and pupal stages, especially in the epidermis. RNAi experiments showed that silencing LdKnk and LdKnk3-5' led to reduced larval weight, cuticle thinning, and increased mortality, while LdKnk3-FL knockdown caused abnormal cuticle thickening and molting disruptions. LdKnk2 knockdown increased epicuticle and endocuticle thickness without visible phenotypic changes. The study highlights the essential roles of LdKnk-family genes in maintaining cuticle structure and integrity, suggesting their potential as targets for RNAi-based pest control.

In this study, we present the first attempt at a molecular phylogenetic analysis of the entire family of Cordulegastridae involving 60% of its known species. Our analysis is in favor of reclassification of the members of the family into four genera: (i) the monophyletic genus Anotogaster Selys, 1854, with the number of known species reduced by three synonymizations; (ii) the genus Cordulegaster Leach in Brewster, 1815 including all members of the boltonii group and, as a preliminary solution, the American species C. virginiae Novelo-Gutiérrez, 2018 and, very tentatively, C. diadema Selys, 1868. The bidentata group forms a genus of its own, for which we restored the name Thecagaster Selys 1854, stat. rev. Cordulegaster pekinensis McLachlan in Selys, 1886, currently considered as Neallogaster pekinensis, was placed by us in Thecagaster as well. The genus Neallogaster Cowley, 1934 needs further investigation involving all remaining species listed in it. The genus Zoraena Kirby, 1890, stat. rev., was recovered to accommodate the remaining American species of Cordulegaster. We synonymized three species of Anotogaster: Anotogaster gregoryi Fraser, 1923 = Anotogaster xanthoptera Lohmann, 1993, syn. nov.; Anotogasterkuchenbeiseri (Förster, 1899) = Anotogaster antehumeralis Lohmann, 1993, syn. nov.; Anotogaster kuchenbeiseri (Förster, 1899) = Anotogaster cornutifrons Lohmann, 1993, syn. nov., based on examination of the existing type specimens. The type of specimens of A. klossi Fraser, 1919 = A. flaveola Lohmann 1993 syn. confirm., were also examined, and their synonymy was confirmed. The isolated populations of A. sieboldii (Selys, 1854) from the archipelagos of Okinawa and Amami Oshima in Japan, respectively, should be regarded as separate species, which will be described elsewhere. Furthermore, we suggest the synonymization of Cordulegaster parvistigma Selys 1873 syn. nov. with Thecagaster brevistigma (Selys 1854) comb. restaur.