RNA Interference in the Egg Parasitoid, Trichogramma dendrolimi Matsumura.

The egg parasitoids, Trichogramma spp, are recognized as efficient biological control agents against various lepidopteran pests in agriculture and forests. The immature stages of Trichogramma offspring develop within the host egg, exhibiting remarkable diminutiveness (approximately 0.5 mm in adult length).

The identification and expression pattern of the sex determination genes and their sex-specific variants in the egg parasitoid Matsumura (Hymenoptera: Trichogrammatidae).

wasps are egg parasitoids of agricultural lepidopteran pests. The sex of is determined by its ploidy as well as certain sex ratio distorters, such as the endosymbiotic bacteria spp. and the paternal sex ratio (PSR) chromosome.

Posterior concentration of during the early embryogenesis of the host dynamically shapes the tissue tropism of in host wasps.

Introduction: The bacterial endosymbiont, spp. induce thelytokous parthenogenesis in certain parasitoid wasps, such as the egg parasitoid wasps spp. To complete the cycle of vertical transmission, displays efficient transovarial transmission by targeting the reproductive tissues and often exhibits strong tissue-specific tropism in their host.

Wolbachia-infected Trichogramma dendrolimi is outcompeted by its uninfected counterpart in superparasitism but does not have developmental delay.

Background: Wolbachia infection increases the superparasitism frequency of Trichogramma females and provides an opportunity for horizontal intraspecific transmission. However, superparasitism may lead to interstrain competition between Wolbachia-infected Trichogramma offspring and their uninfected counterparts. This study investigated the outcome of interstrain intrinsic competition between Wolbachia-infected thelytokous strain (W) and uninfected bisexual strain (B) of Trichogramma dendrolimi.

-Driven Memory Loss in a Parasitic Wasp Increases Superparasitism to Enhance Horizontal Transmission.

Horizontal transmission of the endosymbiont, , may occur during superparasitism when parasitoid females deposit a second clutch of eggs on a host. may increase the superparasitism tendency of Trichogramma wasps by depriving their memory. To test this hypothesis, we investigated the effects of conditioning experience and memory inhibitors (actinomycin D [ACD] and anisomycin [ANI]) on memory capacity, and expressions of memory-related genes ( and ), and superparasitism frequency of -infected (TDW) and uninfected (TD) lines of Trichogramma dendrolimi after conditioning with lemon or peppermint odor.

Penetrance during Wolbachia-mediated parthenogenesis of Trichogramma wasps is reduced by continuous oviposition, associated with exhaustion of Wolbachia titers in ovary and offspring eggs.

Background: Thelytokous Wolbachia-infected Trichogramma wasps are superior to bisexual uninfected wasps regarding biological control programs. However, continuous oviposition weakens the parthenogenesis-inducing (PI) strength of Wolbachia. Whether this reduced PI strength relates to decreases in the titer of Wolbachia in the ovary and offspring eggs of Trichogramma remains unclear.

Evaluation of Sensitivity to Phoxim and Cypermethrin in an Endoparasitoid, Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), and Its Parasitization Efficiency Under Insecticide Stress.

Insecticides can have consequences for beneficial arthropods. Insect parasitoids can contact insecticides through direct exposure spray droplets or residues on crop foliage. Here, we focus on better understand the response of Meteorus pulchricornis (Wesmael), a parasitoid wasp of lepidopteran pests, and its detoxification mechanisms on stress caused by phoxim and cypermethrin.

Phylogenetic signals in pest abundance and distribution range of spider mites.

Background: Attributes of pest species like host range are frequently reported as being evolutionarily constrained and showing phylogenetic signal. Because these attributes in turn could influence the abundance and impact of species, phylogenetic information could be useful in predicting the likely status of pests. In this study, we used regional (China) and global datasets to investigate phylogenetic patterns in occurrence patterns and host ranges of spider mites, which constitute a pest group of many cropping systems worldwide.

Effects of temperature and superparasitism on quality and characteristics of thelytokous Wolbachia-infected Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) during mass rearing.

Thelytokous Wolbachia-infected Trichogramma spp. are widely used egg parasitoids against lepidopteran pests in biological control programs. Wolbachia may manipulate host wasps for superparasitism and is sensitive to temperature.

Co-occurrence of thelytokous and bisexual Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) in a natural population.

Trichogramma dendrolimi is one of the most successful biocontrol agents in China. However, an inundative condition is necessary to obtain acceptable parasitism effect. A good solution to this is the application of its thelytokous counterparts which unfortunately are scarce in field.

Gradual, temperature-induced change of secondary sexual characteristics in infected with parthenogenesis-inducing .

Intersex is an intermediate stage of sexual differentiation in insects. Determining intersex morphology and the cause of its production will aid in the understanding of the mechanism of sexual differentiation in insects. In this paper, -infected ( ) that shows thelytokous parthenogenesis were used as subjects.

Mitochondrial variation in small brown planthoppers linked to multiple traits and probably reflecting a complex evolutionary trajectory.

While it has been proposed in several taxa that the mitochondrial genome is associated with adaptive evolution to different climatic conditions, making links between mitochondrial haplotypes and organismal phenotypes remains a challenge. Mitonuclear discordance occurs in the small brown planthopper (SBPH), Laodelphax striatellus, with one mitochondrial haplogroup (HGI) more common in the cold climate region of China relative to another form (HGII) despite strong nuclear gene flow, providing a promising model to investigate climatic adaptation of mitochondrial genomes. We hypothesized that cold adaptation through HGI may be involved, and considered mitogenome evolution, population genetic analyses, and bioassays to test this hypothesis.

Incidence of Facultative Bacterial Endosymbionts in Spider Mites Associated with Local Environments and Host Plants.

Spider mites are frequently associated with multiple endosymbionts whose infection patterns often exhibit spatial and temporal variation. However, the association between endosymbiont prevalence and environmental factors remains unclear. Here, we surveyed endosymbionts in natural populations of the spider mite, , in China, screening 935 spider mites from 21 localities and 12 host plant species.

[Prokaryotic expression of trigeminy artificial fusion gene of Leptospira interrogans and the immunogenicity of its products].

Objective: To construct lipL32/1-lipL21-OmpL1/2 fusion gene of Leptospira interrogans and its prokaryotic expression system, and to identify the immunogenicity of its products.

Methods: PCR using linking primers was applied to construct lipL32/1-lipL21-OmpL1/2 fusion gene and a prokaryotic expression system of the fusion gene was then established using routine genetic engineering technique. SDS-PAGE was used to examine output of the target recombinant protein rLipL32/1-LipL21-OmpL1/2.