Insects最新文献

The native biodiversity of oceanic islands is threatened by human-driven disturbance and by the growing number of species introductions which often interfere with natural ecological processes. Here, we aim to evaluate the effect of anthropogenic disturbance on plant-pollinator interactions in the native forest communities of an oceanic island (Terceira, Azores, Portugal). We found that native species predominated in preserved sites compared to disturbed ones and that the extant plant-pollinator interactions were mostly dominated by generalist species. Dipterans, particularly hoverflies, emerged as the primary flower visitors, while introduced hymenopterans (Apis mellifera and Bombus terrestris) and native beetles were locally important, respectively, in disturbed and preserved sites. Human-driven disturbance seems to be responsible for the observed differences in flower abundance and species composition between sites and to drive changes in specific network metrics (namely nestedness, interaction strength asymmetry, and specialization), particularly in one of the study areas. Our findings also suggest that native generalist species provide ecological opportunities that can facilitate the establishment of introduced species through their broad interaction networks.

Honey robbing, which typically occurs during times of food scarcity, is a perilous foraging strategy for bee colonies and presents a formidable challenge in the realm of beekeeping. This article provides a comprehensive and multifaceted exploration of honey robbing, including the morphology, behavioral traits, timing, and scope of this phenomenon. This exploration elucidates the specific manifestations of honey robbing, offering readers a deeper understanding of its various facets. Next, this article investigates the root causes of honey robbing by examining both abiotic and biotic factors. The resulting harms are outlined, and corresponding preventive and control measures are suggested. Finally, the article succinctly summarizes the current obstacles in research related to honey robbing and outlines promising avenues for future exploration. The objective of this study was to elucidate the occurrence mechanism of honey robbing, ultimately aiming to contribute to the sustainable growth of the beekeeping industry.

Poultry litter waste management poses a significant global challenge, attributed to its characteristics (odorous, organic, pathogenic, attracting flies). Conventional approaches to managing poultry litter involve composting, biogas generation, or direct field application. Recently, there has been a surge of interest in a novel technology that involves the bioconversion of organic waste utilizing insects (known as entomoremediation), particularly focusing on black soldier fly larvae (BSFL), and has demonstrated successful transformation of various organic waste materials into insect meal and frass (referred to as organic frasstilizer). Black soldier flies have the capacity to consume any organic waste material (ranging from livestock litter, food scraps, fruit and vegetable residues, sewage, sludge, municipal solid waste, carcasses, and defatted seed meal) and convert it into valuable BSFL insect meal (suitable for animal feed) and frass (serving as an organic fertilizer). The bioconversion of poultry litter by black soldier flies offers numerous advantages over traditional methods, notably in terms of reduced land and water requirements, lower emissions, cost-effectiveness, swift processing, and the production of both animal feeds and organic fertilizers. This review focuses on the existing knowledge of BSFL, their potential in bioconverting poultry litter into BSFL meal and frass, and the utilization of BSFL in poultry nutrition, emphasizing the necessity for further innovation to enhance this sustainable circular economy approach.

The cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is an invasive polyphagous pest that has been reported in several tomato-producing Mediterranean countries. However, information regarding the impact of temperature variations on its potential damage and population dynamics on this crop is limited. The effect of four temperatures (20 ± 1 °C, 25 ± 1 °C, 30 ± 1 °C and 35 ± 1 °C) on the development, reproduction, and population growth parameters of P. solenopsis on tomatoes under controlled laboratory conditions was investigated using age-stage two-sex life tables. The increase in temperature caused a significant decrease in the developmental periods of all instars except eggs. The shortest durations of the life cycle (29.58 ± 0.28 days for females and 13.91 ± 0.25 days for males), the adult preoviposition period (APOP), and the total preoviposition period (TPOP) (APOP: 7.78 ± 0.09 days and TPOP: 18.33 ± 0.13 days) were obtained at 35 ± 1 °C. Fecundity varied with temperature, and the highest value was recorded at 30 ± 1 °C (183.29 ± 7.13 eggs/female). The highest average net reproduction rate (R₀) (154.24 ± 14.681 offspring/female), intrinsic rate of increase (r) (0.222 ± 0.0036 d^-1), and finite rate of increase (λ) (1.248 ± 0.00495 d^-1) were observed at 35 ± 1 °C. A simulation of population increase and structure under different temperatures over a period of 90 days revealed that the greatest expected population size was at 35 ± 1 °C, with the completion of four overlapping generations. The data from this study provide valuable information for adapted pest management approaches against P. solenopsis on tomato crops.

Bt has been applied as a gene source for insect-resistant transgenic crops, which represents efficient control of insect pests. In this study, we evaluated the pesticidal specificity of one Bt maize strain, DBN9936, that expresses Cry1Ab protein in Spodoptera litura larvae. The results showed that this Bt maize is active against the younger larvae while causing a sublethal effect on older larvae. To further assess the biological responses of S. litura under sublethal Cry1Ab exposure, the relative concentrations of Cry1Ab in different tissues of fifth instar larvae were investigated, indicating that Cry1Ab is transported along the gut and out of the body via excretion or into the hemocoel and lead to sequestration by molting. Furthermore, the result of ultrastructural observation in sublethal Cry1Ab-treated midgut, namely an increase in lysosome number, with the lysosomal activity activation simultaneously provides a strong indication that lysosome plays an active role in response to sublethal Cry1Ab exposure.

Chlorophorus Chevrolat, 1863, one of the most species-rich genera of Clytini, comprises 36 subgenera and 302 species/subspecies, with some species being of significant economic importance. To assess the monophyly and subgeneric system of this genus, we newly obtained mitochondrial genomic data from 21 species of Chlorophorus via high-throughput sequencing and reconstructed the phylogeny of this genus using ML and BI methods. The mitochondrial genomes of all sequenced Chlorophorus species were found to comprise 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and one non-coding region (control region, CR), reflecting a highly conserved gene arrangement. The mitochondrial genomes of the 21 Chlorophorus species range from 15,387 bp to 15,779 bp in length, and all exhibited AT bias. Analysis of the non-synonymous and synonymous substitution rates revealed that ATP8 has the highest evolution rate, whereas COI has the lowest. Further, phylogenetic analyses were performed based on different datasets (13 PCGs + 2 rRNAs, 13 PCGs + 2 rRNAs + 22 tRNAs, PCG123, PCG12) using maximum likelihood (ML) and Bayesian inference (BI) methods. The results indicate that Chlorophorus is monophyletic, but the subgenera Humeromaculatus Özdikmen, 2011; Immaculatoides Özdikmen, 2022; Brevenotatus Özdikmen, 2022; and Chlorophorus (s. str.) Chevrolat, 1863, are not monophyletic. Based on the comparison of male genitalia, we found that the sclerites of the endophallus may exhibit phylogenetic signals for the genus.

Spotted wing drosophila (SWD) is a pest that causes damage due to the female laying eggs under the skin of ripe fruit, from which a larva emerges, causing its collapse and reducing its commercial value. Due to the importance of this pest, monitoring its population is the starting point for any control program; however, there is no early monitoring plan within management tasks, nor are there studies on behavior, the optimization of traps, or their baits. This research proposes the evaluation of a monitoring system with encapsulated baits and adhesive traps that allow effective control. The encapsulated bait was selected after evaluating three options in olfactometric tests in the laboratory; the most attractive bait was WVM, with 70% of visits to the stimulus and 30% to its control, unlike SAG I and SAG II, whose values did not exceed 40% attraction. Among the expected results is the availability of a new format of attractive bait for SWD with a better release rate over time, and the information obtained will allow the generation of SWD population curves for the area, which is essential for decision-making. This study will contribute from the perspective of nanomaterials, insect biology, agricultural entomology, and pest monitoring.

Bombyx mori (Lepidoptera: Bombycidae) is an important economic insect, which mainly feeds on mulberry leaves and is widely used in many research fields. The growth and development of silkworm larvae are easily affected by the use of chemical insecticides such as novaluron, a benzoylurea insecticide. However, the effect of novaluron exposure on the reproduction of silkworms has not yet been studied. In this study, the effect of trace novaluron on the oviposition of silkworms and histopathological changes were first evaluated, and then the gene expression level changes after novaluron exposure were also determined by employing qRT-PCR. It was found that the number of eggs and the hatching rate of eggs in silkworms decreased significantly after feeding on leaves with a trace amount of novaluron (p ≤ 0.01). Furthermore, novaluron exposure could affect the development of ovary tissue by reducing the number of oocytes and oogonia in the ovaries of silkworms fed with novaluron. In addition, the transcription levels of genes related to ovary development (Vg, Ovo, Otu, Sxl-S and Sxl-L) and hormone regulation (EcR and JHBP2) showed varying degrees of downregulation at 24 h, 48 h, and 72 h after novaluron treatment (p ≤ 0.05). Therefore, we speculated that novaluron can affect the energy metabolism, ovary development, and egg formation of silkworms, thus leading to reproductive disorders of silkworms after novaluron exposure.

The large-scale insect rearing sector is expected to grow significantly in the next few years, with Hermetia illucens L. (black soldier fly, BSF) playing a pivotal role. As with traditional livestock, it is essential to improve and ensure BSF welfare. A starting point can be an adaptation of the Five Freedoms framework. Feed availability must be optimized to meet larvae nutritional needs (freedom from hunger) while maximizing substrate conversion efficiency. Similarly, rearing density needs to be optimized to ensure well-being, particularly in large-scale operations. In this study, Control (commercial laying hen feed) and Omnivorous substrates (vegetable and meat) were used as dietary regimes. In the first trial, three feeding rates were tested: 50, 100, and 200 mg feed/larva/day; in the second trial, three rearing densities were evaluated: 5, 10, and 15 larvae/cm². Performance parameters, including final larval weight, final frass biomass, growth rate, substrate reduction, feed conversion ratio, larval length, survival rate, larvae chemical composition, and process optimization, were studied. Our results show that a feeding rate of approximately 90 mg feed/larva/day in the Omnivorous diet and 175 mg feed/larva/day in the Control diet, along with a rearing density of 5 and 7.57 larvae/cm², respectively, in the Omnivorous and Control diets, produced optimal growth performances ensuring larval well-being. This outcome offers valuable insights for implementing good welfare practices in the insect farming sector and optimizing rearing management and efficiency.

Camel bot fly (Cephalopina titillator) larvae cause myiasis in domesticated and wild camels, resulting in significant economic losses to the camel industry and posing a serious global public health concern. To date, only one mitochondrial genome (mitogenome) of C. titillator isolated from the Alxa Bactrian camel has been reported. Herein, C. titillator was isolated from the Junggar Bactrian camel to assemble a complete circular mitogenome with a length of 16,552 bp encoding 13 protein-coding genes, 22 tRNA genes, and two rRNA genes. The mitogenome showed a high A + T content (73.31%), positive AT-skew (0.12), and negative GC-skew (-0.34) base composition patterns. All protein-coding genes (PCGs) employed ATG, ATA, ATT, GTG, or TCG as the start codons and TAA, TAG, or single T as the stop codons. Similar to other parasites in the Oestridae subfamily, the mitogenome was structurally conserved, with genes retaining the same order and direction as those in the ancestral insect mitogenome. The phylogenetic analysis clustered this species with the Oestrinae, showing that the subfamily did not exhibit monophyly. C. titillator isolated from the Junggar Bactrian camel was found to be a sister lineage to that isolated from the Alxa Bactrian camel. Despite the lack of data on the mitogenome of C. titillator isolated from dromedaries in the Middle East, phylogenetic analysis of C. titillator isolated from Xinjiang revealed one distinct lineage of the Xinjiang camel nasal bot fly. In conclusion, this study reports the complete mitogenome of Xinjiang C. titillator for the first time, providing valuable data for future studies on the phylogenetic relationships in this subfamily.