Flies of the Colocasiomyia toshiokai species group depend exclusively on infl orescences/infructescences of the aroid tribe Homalomeneae. The taxonomy and reproductive biology of this group is reviewed on the basis of data and samples collected from Southeast Asia. The species boundaries are determined by combining morphological analyses and molecular species delimitation based on sequences of the mitochondrial COI (cytochrome c oxidase subunit I) gene. For the phylogenetic classifi cation within this species group, a cladistic analysis of all the member species is conducted based on 29 parsimony-informative, morphological characters. As a result, six species are recognised within the toshiokai group, including one new species, viz. C. toshiokai, C. xanthogaster, C. nigricauda, C. erythrocephala, C. heterodonta and C. rostrata sp. n. Various host plants are utilised by these species in different combinations at different localities: Some host plants are monopolized by a single species, while others are shared by two or three species. C. xanthogaster and C. heterodonta cohabit on the same host plant in West Java, breeding on spatially different parts of the spadix. There is a close synchrony between fl ower-visiting behaviour of fl ies and fl owering events of host plants, which indicate an intimate pollination mutualism.

Anoplophora glabripennis (Asian longhorned beetle) is a wood-boring pest that can inhabit a wide range of healthy deciduous host trees in native and invaded areas. The gut microbiota plays important roles in the acquisition of nutrients for the growth and development of A. glabripennis larvae. Herein, we investigated the larval gut structure and studied the lignocellulose activity and microbial communities of the larval gut following feeding on different host trees. The larval gut was divided into foregut, midgut, and hindgut, of which the midgut is the longest, forming a single loop under itself. Microbial community composition and lignocellulose activity in larval gut extracts were correlated with host tree species. A. glabripennis larvae fed on the preferred host (Populus gansuensis) had higher lignocellulose activity and microbial diversity than larvae reared on either a secondary host (Salix babylonica) or a resistant host (Populus alba var. pyramidalis). Wolbachia was the most dominant bacteria in the gut of larvae fed on S. babylonica and P. alba var. pyramidalis, while Enterococcus and Gibbsiella were the most dominant in larvae fed on P. gansuensis, followed by Wolbachia. The lignocellulose-degrading fungus Fusarium solani was dominant in the larval gut fed on different host trees. Functional predictions of microbial communities in the larval gut fed on different resistant host trees suggested that they all play a role in degrading lignocellulose, detoxification, and fixing nitrogen, which likely contribute to the ability of these larvae to thrive in a broad range of host tree species.

The two-spotted spider mite, Tetranychus urticae, is an important mite pest worldwide. It often leads to reduced crop yields or poor marketability of the produce and has already developed resistance to many acaricides. In this study, the pathogenicity of the entomopathogenic fungus (EPF), Acremonium hansfordii, to T. urticae and its side effects on the predatory mite Neoseiulus barkeri were compared. The toxicity of A. hansfordii was evaluated on T. urticae at 1.0×104, 1.0×106, 1.0×108 conidia/mL concentrations and predatory mite N. barkeri at 1.0×108 conidia/mL under experimental conditions at 25±1°C, 75±5% RH and 16L: 8D photoperiod. The effects of EPF on the development of the F0 and F1 generation of predatory mites were also assessed at 1.0×108 conidia/mL concentration. The results showed that the corrected mortality of T. urticae at three tested concentrations were 36.67%, 53.67% and 66.33% within 11d, and the median lethal time were 14.39 d, 9.84d and 7.99d, respectively. The corrected mortality of N. barkeri was only 3.9% after 11d at 1×108 conidia/mL concentration. Some hyphae of A. hansfordii were detected on the surface of treated T. urticae but not on N. barkeri body after 7d. After N. barkeri females were treated with 1.0×108 conidia/mL, the preoviposition period of the F0 generation was prolonged 1.56 times and the other life history parameters have no significant differences; similar patterns were also shown in the F1 generation. A. hansfordii showed strong pathogenicity against T. urticae but did not significantly adversely influence N. barkeri. Therefore, the combination of A. hansfordii and N. barkeri has the potential to be used for the control of T. urticae in the future.

The present study was conducted to evaluate sublethal effects of B-azolemiteacrylic on the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). Female adults of T. urticae were exposed to LC10 and LC30 of the acaricide, and the effects on treated females and their offspring were evaluated. The results showed that the fecundity of F0 female adults treated with LC10 and LC30 of B-azolemiteacrylic was reduced by 30.9 and 39.2%, respectively. Longevity and oviposition period of the females were significantly reduced as well. The developmental duration of egg and deutonymph stage of the F1 generation were not significantly different from that of the control. The protonymph stage after LC30 treatment lasted significantly longer, whereas the larva, deutonymph and female stage were significantly shorter than the control. The oviposition period of the F1 generation was significantly shortened, the fecundity of each female decreased significantly, and the ratio of female-to-male was reduced too. Moreover, the average generation period of T. urticae after LC10 and LC30 treatments was shorter than that of the control, and the net production rate (R0), intrinsic rate of increase (rm) and finite rate of increase (λ) were all reduced by 33.3, 7.5 and 1.9% (LC10 treatment) and by 51.3, 14.8 and 3.6% (LC30 treatment), respectively. The population doubling time was prolonged by 7.5 and 14.8% after LC10 and LC30 treatments, respectively, compared with the control. These results indicate that B-azolemiteacrylic may effectively inhibit the development rate of the F0 and F1 populations of T. urticae, which will help design integrated strategies for the comprehensive control of T. urticae and rational use of pesticides in the field.