Bulletin of Entomological Research最新文献

The family Streblidae is a significant grouping of dipteran insects within the superfamily Hippoboscoidea, which parasitizes the body surface of bats. With the global spread of bat-related pathogens in recent years, Streblidae has gained increasing attention due to its potential for pathogen transmission. A sample of Brachytarsina amboinensis was sequenced on the B. amboinensis were obtained, compared with available Streblidae mitogenomes, and the phylogeny of Hippoboscoidea was reconstructed. The results indicate that the mitochondrial genome of B. amboinensis exhibits a relatively high degree of conservation, with an identical gene count, arrangement, and orientation as the ancestral insect's genome. Base composition analysis revealed a strong bias towards A and T in the base composition. Selection pressure analysis indicated strong purifying selection acting on cox1. Pairwise genetic distance analysis showed that cox1 evolved at a relatively slow rate. Regarding phylogenetic relationships, the constructed phylogenetic trees using Bayesian inference and Maximum Likelihood methods supported the monophyly of the Hippoboscoidea, Glossinidae, Hippoboscidae, and Nycteribiidae clades, with high nodal support values. Our research confirmed the paraphyly of the families Streblidae. In the familial relations between Nycteribiidae and Streblidae, New World Streblidae share a closer kinship with Nycteribiidae. This contrasts with prior findings which indicated that Old World Streblidae share a closer kinship with Nycteribiidae. This study not only enhances the molecular database for bat flies but also provides a valuable reference for the identification and phylogenetic analysis of Streblidae.

Negative relationships between the parental age and offspring life history traits have been widely observed across diverse animal taxa. However, there is a lack of studies examining the influence of parental age on offspring performance using mites, particularly phytoseiid predators as subjects. This study explored the influence of maternal age on offspring life history traits in Amblyseius herbicolus (Chant) (Acari: Mesostigmata), a phytoseiid predatory mite reproducing through thelytokous parthenogenesis. We hypothesised that increased maternal age negatively impacts offspring traits, including developmental duration, body size, fecundity and lifespan. Amblyseius herbicolus was reared under controlled laboratory conditions, and the life history traits of offspring from mothers of varying ages were analysed using linear mixed-effect models. Our results showed that the increase in maternal age significantly reduced individual egg volume, but did not significantly affect offspring developmental duration, body size, fecundity or lifespan. These findings indicate that while older A. herbicolus females produced smaller eggs, the subsequent performance (i.e. body size, fecundity and lifespan) of offspring remained largely unaffected, suggesting possible compensatory mechanisms in the offspring or alternative maternal provisioning strategies. The results of this study offer useful insights into the reproductive strategies of phytoseiid predators and asexually reproducing species, enhancing our understanding of how maternal age affects offspring fitness. Further studies can examine how offspring of A. herbicolus from mothers of different ages perform under adverse environmental conditions.

Microorganisms symbiotic with insects, whether permanently or temporarily, play a crucial role in the nutrition, development, reproduction, defence, and metamorphosis regulation. In some Lepidoptera, oviposition-deterrent pheromones (ODPs) on egg surface were used by pregnant females to modify the behaviour of conspecifics to avoid excessive competition for limited resources. In this study, we constructed four different Spodoptera litura groups, including, OH, OA, SH, and OA, which either feed on different hosts or grow in different environments. The 16S rDNA libraries of microbes from the egg surface of the four groups were constructed and sequenced. According to alpha and beta diversity indices, the microbes in environments and diets considerably influenced the richness, diversity, and community compositions of the microbiota on egg surfaces. The quantity of the main ODP components and the corresponding oviposition-deterrent activity among four groups were significantly differed among the four groups. The result of this study revealed that altering of microbes in environments or diets considerably changed the contents of ODP and oviposition-deterrent activity. As ODPs impart oviposition-deterrent activity towards closely related species, the findings of this study suggest that we should pay more attention to the role of symbiotic microorganisms in changing the ability of insects, especially sympatric species, to occupy the optimal niche when developing novel pest-control strategies.

In December 2017 the Venetian Region (local Authority), financed the creation of the Operational Group (OG) 'Serinnovation', within the framework of the Rural Development Plan supported by the European Community. The OG aims at coordinating and spreading innovation in sericulture through mechanisation of processes and centralisation of some rearing steps, the use of waste as by-products and traceability to promote local productions. The project acts on perceived quality by increasing the added value, through production cost efficiency, and on the recovery of the waste material for further applications (circular economy). The final target was to develop a niche-process to obtain traceable 'Made-in-Italy' silk for the luxury market and non-textile applications. A first strategy to increase the efficiency of the process was to build an automatic leaf cutting machine to prepare the feed for the first three instars of the silkworm (Bombyx mori Linnaeus). This new machine - based on a patent - was validated through several tests and compared with the cutting system previously used. The study was completed by a bioassay of production and survival rate associated with the introduction of this innovation. The results showed that labour saving is in the order of 10% compared to a semi-manual process, the leaf quality is not affected, survival of larvae and silk production are not significantly different from the control. This methodology is proposed as a study case for other similar mechanisation processes in entomological production, as the impact of innovations on insect physiology should be carefully considered.

Invasive species threaten biodiversity on a global scale. The success of invasions depends on the species' adaptation to the different environmental conditions of new territories. Studies show that invasive insects present evolutionary changes in wing morphology in areas they are introduced to in response to abiotic conditions. In the last decade, the Asian Drosophila nasuta fly invaded and spread widely throughout Brazil. This insect has preferences for conserved environments and is related to the likely reduction in the abundance of native drosophilids in the Atlantic Forest. Ecological niche modelling analyses showed that rainfall and temperature are the main factors which delimit the geographic distribution of this species. Herein, we verified the existence of significant differences in the wing sizes of D. nasuta in Brazil and evaluated the influence of abiotic factors (rainfall and temperature) on the observed patterns. We conducted 11 measurements on the right-side wings of 240 D. nasuta males collected in the Amazon Forest, Caatinga, Cerrado and Atlantic Forest. Statistical analyses revealed the existence of two groups: one with larger wings, which brought together samples from locations with the lowest temperatures; and one with smaller wings, which corresponded to places with a hotter climate. One explanation for this result is the fact that large wings favour greater heat capture by flies in colder climates, increasing their survival chances in these environments. These rapid evolutionary changes in D. nasuta in this first decade of invasion in Brazil reveal the enormous adaptive potential of this species in this megadiverse country.

The fruit fly Ceratitis capitata is a successful generalist due to the trade-off between different variables in its life history traits. The present study aimed to assess some life history traits of C. capitata recovered from peach, plum and fig, three key host species, under the climatic conditions of an irrigation oasis in the arid province of San Juan, Argentina. Pupal abundance, sex ratio and morphometric parameters such as pupal and adult weight, pupal volume, wingspan and head-caudal length were influenced by the host in which the larvae were reared. Sexual maturity, measured as the peak of calling (pheromone emission), was homogeneous on the sixth and seventh days after emergence, but males recovered from fig showed early calling activity on the third day after emergence. The plasticity of C. capitata to adapt its life history traits to specific nutrient variations within the larval environment allows it to colonise and establish populations where key hosts, as those studied here, are available. The knowledge of the interactions between host fruit trees and C. capitata populations provides helpful information for planning the management of local orchards and urban fruit plantations within irrigation oases, taking into consideration the concept of key hosts as peach and fig.

Phytoplasmas are phloem-limited bacteria that are primarily transmitted by hemipteran insects and are emerging threats to Camptotheca acuminata Decne plants due to their associations with a witches' broom disease. Despite numerous studies, there has been no report on insect transmission of phytoplasma among C. acuminata. Here, transmission characteristics of the leafhopper, Empoasca paraparvipenis Zhang and Liu, 2008 and the phytoplasma in plant leaves through PCR quantification are described. The interaction between C. acuminata-phytoplasma and insect vectors was examined by analysing the impact on the life characteristics and progeny population in a temperature-dependent manner. Phytoplasma-infected C. acuminata plant exhibited symptoms including shorter internodes, weak and clustered branches, shrunken and yellowed leaves, and red leaf margins. The acquisition and transmission time of bacterial-infected third-instar nymphs of insect vectors were 10 (11.11%) and 30 min (33.33%), respectively. A single insect vector can infect a plant after 72 h of feeding, and the incidence rate of disease increases with the number of insects following 11-100% from single to 20 insects. The development time of the infected insect vectors (1-3 instars) was significantly shorter than that of the healthy insects, and the development duration of instar individuals was longer. In progeny populations, the higher the phytoplasma concentration (88-0% for 1-5 instars nymph, female and male adults), the shorter the development time and the longer the adult lifetime (both male and female). These findings provided research evidence of phytoplasma transmission by insect vectors; however, further investigation of the mechanisms for prevention and management of phytoplasma diseases is needed.

Understanding why animals choose one food over another is one of the key questions underlying the fields of behaviour ecology. This study aims to test if ladybird beetle, Propylea dissecta Mulsant (Coleoptera: Coccinellidae) can forage selectively for nutrients in order to redress specific nutritional imbalances to maximise their fitness. We hypothesised that the presence of more food choices leads to bad decisions in terms of their food selection which ultimately negatively affects the mating and reproductive parameters of P. dissecta. To test this, we first manipulated the predator's nutritional status by rearing them in five separate dietary groups from first instar larvae to newly emerged adult stage. Thereafter, we tested their food choice between five different foods, i.e. Aphis craccivora Koch, Aphis nerii Boyer de Fonsclombe, conspecific eggs, heterospecific eggs and mixed pollen grains, equidistantly placed in a Petri dish. Based on the food choice of the newly emerged adults, they were reared on the chosen diet for 10 days. Thereafter, adults were paired with their opposite sex (collected from stock culture reared on A. craccivora) and mating and reproductive parameters were recorded. Our results suggested that the variety of food did not affect the food choice of ladybird beetle, P. dissecta. They tend to choose their natural diet, i.e. aphid in each dietary regime. We found that previous dietary regime, i.e. larval dietary regime, significantly influences the mating and reproductive parameters of both the male and female except for the time to commence mating by the male. Food choices of adult beetles were found to significantly influence the time to commence mating, average fecundity and per cent egg viability in males and only mating duration in females. Our findings suggest that P. dissecta consistently made optimal decisions when facing various food choices. They consistently preferred their natural and preferred food choice over others, indicating a strong food selection behaviour.

Bagrada bug, Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae), is an invasive pest of cole crops in the United States. Because it also feeds on widespread weeds and persists in natural habitats surrounding crop fields, conventional control strategies are often ineffective at providing long-term control. One egg parasitoid, Gryon aetherium Talamas (Hymenoptera: Scelionidae), is a promising biological control candidate because of its ability to parasitise B. hilaris buried eggs. Recently, adventive populations of G. aetherium were recovered from sentinel eggs in California along with a native egg parasitoid, Ooencyrtus californicus Girault (Hymenoptera: Encyrtidae). A better understanding of these parasitoid species' spatial preference for foraging and their possible competitive interactions will help evaluate their host suppression potential. We compared the foraging abilities of these two parasitoid species for eggs deposited below and above ground. We also investigated the effect of interspecific competition on host suppression and the ability of O. californicus to parasitise eggs previously parasitised by G. aetherium. G. aetherium parasitised naturally and manually buried eggs, whereas O. californicus did not. In another experiment, O. californicus parasitised eggs glued to cards, but not in the presence of sand. Results suggest that G. aetherium may be negatively affected by the presence of O. californicus, and there was a slight but significant reduction in total host mortality when the parasitoids were present together. However, the inability of O. californicus to forage in soil likely limits negative interactions between these two species, and the two parasitoids may ultimately complement each other.