The incidence of pupal diapause in the flesh fly, Boettcehrisca peregrina (Robineau-Desvoidy), was examined in 11 colonies originating from Japan (3 colonies), Vietnam (1), Sri Lanka (4), Indonesia (2) and Papua New Guinea (1). The Japanese, Vietnamese and Papua New Guinean colonies entered pupal diapause in response to a short-day photoperiod at 20℃, but there was a difference in diapause incidence among them. Diapause incidence in two Japanese colonies, Bp (Tokyo) and Bp (Mie), was 100% under 13L : 11D and 12L : 12D, respectively. Although the latitudinal difference was only 0.8 degree between the original localities of these colonies, they showed a large difference of 1hr 20 in in their 50% critical photoperiod of diapause incidence. Maximum diapause incidence in other colonies was 20% in Bp (Nabekawa) of Japan, 3% in Bp (Lai Chau) of Vietnam and 35% in Bp (Boroko) of Papua New Guinea. The remaining colonies, Bp (Sri A), Bp (Sri B), Bp (Adams), Bp (forest) of Sri Lanka, Bp (Luwuk) and Bp (Toili) of Indonesia did not enter diapause at any of the photoperiods examined (9L : 15D-16L : 8D). The relationship between maximum diapause incidence and latitude are discussed with 23 colonies including 12 previously studied. A population having 50% diapause incidence was estimated to be found at a latitude of 27 to 28°N in Japan.

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Tripteroides ponmeki sp. n. of the subgenus Rachionotomyia is described from specimens collected in Khammouane Province, Lao PDR. The larva of this species differs significantly from other species of the subgenus in having unique modifications in head seta 1-C which is stout with many hairs apically and thoracic setae 6-M and 7-T which are not stout and not spinose and without basal arm. The description includes illustrations and photographs of the adults, male and female genitalia, pupa and fourth-instar larva. The larva breeds mainly in bamboo internodes in rain forests.

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The female sex pheromone of the house dust mite Dermatophagoides farinae was identified as 2-hydroxy-6-methylbenzaldehyde (HMB). Sexual activity was induced by exposing 5-50 ng doses of synthetic HMB, while its content was estimated to be 6.47±0.69 ng per female and 0.77±0.30 ng per male. We concluded that the apparent response of males only towards females is attributed to ca. 8.4-fold difference in the HMB content between both sexes.

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Lactate dehydrogenase (LDH) activity is generally detected by reversible reaction using a combination of a substrate and a coenzyme, that is lactate and NAD (NAD-dependent LDH), or pyruvate and NADH (NADH-dependent LDH). In Anopheles stephensi larvae, NAD-LDH and NADH-LDH activities were high and were easily detected after polyacrylamide gel electrophoresis (PAGE), while in Culex pipiens molestus larvae, NADH-LDH could be detected, but NAD-LDH showed very low activity. According to enzyme histochemical studies, Cx. p. molestus had NAD-LDH at the same localities as An. stephensi did, but its activity was very low. NAD-LDH activity of Cx. p. molestus larvae is, therefore, greatly inhibited by the LDH-inhibitor, which is present in the cytosol of the gastric caeca and midgut, and also in the haemolymph. Among the eight mosquito species examined, LDH-inhibitory activity was highest in the species with low NAD-LDH activity, such as Cx. p. molestus. The LDH-inhibitor was seen to specifically inhibit NAD-LDH activity. Although lactate accumulated in An. stephensi larvae, both NAD-LDH and NADH-LDH were active in this species. While in Cx. p. molestus larvae, although neither lactate nor pyruvate was accumulated, NAD-LDH activity was very low. The LDH-glycolysis could be less active. These results suggested that Cx. p. molestus larvae use some other glycolysis.

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Seven Japanese serows, Capricornis crispus, with clinical signs of mange were used for parasitological and histopathological examinations. Five of the seven animals examined were positive only for Chorioptes mites. On the other two animals, however, a mixed infestation with Sarcoptes scabiei and Chorioptes mites was observed. This Chorioptes mite was proposed as a new species, Chorioptes japonensis Takahashi et Nogami, sp. nov. Histopathologically, parakeratotic and hyperkeratotic crusts were observed in the epidermis, and many cross-sections of S. scabiei mites were also found in the focal thickened stratum corneum. Chorioptes mites were observed on all Japanese serows examined from 1975 to 1997. However, S. scabiei were only observed on the two animals examined in 1996 and 1997. Before then, S. scabiei were not observed.

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