Investigation was carried out on 48 different kinds of herb medicine in China and Japan for the purpose of isolating mite infestation. Fourteen families, 20 genera and 37 species, totaling 265 individuals of mites were isolated from 30 kinds of herb medicine in China. Among them, 16 species of Prostigmata and 14 species of Astigmata mites were obtained in the greatest numbers. Tarsonemus granarius was the dominant Prostigmata-species both in China and Japan. Haplochthonius simplex, Chryptostigmata, which is a household species, was abundantly obtained from Japanese samples. From the species composition obtained, it might be deduced that mite infestation of Chinese herb medicine occurs in storage houses.

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Spider toxins in the venom of Nephila clavata L. Koch were investigated and 4 kinds of closely related toxic components, JSTX-1,2,3 and 4,were chemically characterized as follows : JSTX-1,2,4-dihydroxyphenylacetyl-asparaginyl spermine; JSTX-2,N-(2,4-dihydroxyphenylacetyl-ornithyl-asparaginyl)-N'-(putreanyl-putreanyl) cadaverine; JSTX-3,N-(2,4-dihydroxyphenylacetyl-asparaginyl)-N'-(aminopropyl-putreanyl) cadaverine; JSTX-4,N-(2,4-dihydroxyphenylacetyl-asparaginyl)-N'-(arginyl-ornityl) cadaverine. The toxins inhibited glutaminergic neurotransmission in arthropods.

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Histopathological effects of an insect growth regulator, pyriproxyfen, on the larvae of Aedes aegypti were studied by treating with concentrations at 1 and 10ppb for 24 and 48hr. At the light microscopic level, vacuolation and inhibition of development of imaginal buds in various grades were seen. Electron microscopy revealed the lack of cuticular formation and vacuolation of epidermal cells. In the midgut and Malpighian tubules, disrupted mitochondria, abundant vacuoles and poorly-structured cytoplasmic organelles were observed. These findings suggest possible histolysis of the cells induced by pyriproxyfen.

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Each volatiles from Dermatophagoides farinae and D. pteronyssinus consisted of unique mixtures of monoterpenoid, that is, D. farinae contained nerylformate, neral, and geranial as monoterpenoids, among which neral (28.2%) was the major component. On the other hand the volatile of D. pteronyssinus was composed of nerylformate, neral, geranylformate and geranial, among which geranial (36.6%) was the major fraction. Both species were also characterized by their hydrocarbon profiles. The D. farinae hydrocarbon consisted of pentadecane (32.2%), while that of the D. pteronyssinus was a mixture of heptadeca-(Z, Z)-6,9-diene (21.8%) and (Z)-8-heptadecene. Although these profiles may be useful for identifying each species, no behavioral responses against those volatiles were detected such as the alarm pheromone and aggregation pheromone found in other related mites.

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Ancystropus notopteris sp. n. is described on the adult and immature stages. The males of all known species of Ancystropus except A. leleupi and the immature stages of A. kanheri, A. eonycteris, A. zeleborii and A. taprobanius are described or redescribed. Apomorphic characters of Ancystropus are evaluated, and are thought to have come out through sympatric speciations of mites on a few hosts independent of host speciations.

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In an attempt to predict the epidemic incidence of Japanese encephalitis in human population, a long-term surveillance on Culex tritaeniorhynchus, the vector of Japanese encephalitis virus, has been carried out at several observation stations in Toyama Prefecture since 1969. The numbers of the mosquito captured by the light trap had been decreasing since 1965 until 1977,and then began to reverse from 1978. This increasing trend appeared clear in 1982,although some decreases in the numbers were observed in 1984,1986 and 1988 in comparison with the previous years. The major cause of increase in the numbers of the mosquito may be attributed to the acquisition of insecticide resistance. Aerospray of agricultural pesticides or fungicides may not inhibit the appearance of the mosquito. In fact, the resistant/sensitive ratios for fenthion, fenitrothion and malathion of a resistant strain of C. tritaeniorhynchus, established in Toyama Prefecture, were 6,557,5,272 and 2,454,respectively. In an exposure experiment with the pesticide aerospray over a paddy field lethalities ranging from 7.6 to 71.6% were observed with the resistant strain of C. tritaeniorhynchus; these percentages could not be compared with the complete death of a sensitive strain.

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[in Japanese]

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[in Japanese]

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Ovitraps were used to carry out weekly surveys of Aedes albopictus at 58 locations in the residential areas of Tokushima City. The eggs of Ae. albopictus were dominant in traps at all locations, and were found from May through early December. Egg density was particularly high in hillside areas. The mean number of eggs per trap sharply increased in July and peaked in early August. The percentage of ovitraps in which eggs were found was also high during this period. A clear correlation between the mean number of eggs and the percentage of traps infested was observed, especially in hillside areas.

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Twelve human cases of ixodid tick-bite in Kochi Prefecture, Japan, since 1982 were recorded. Causative tick species were : Ixodes nipponensis (5 cases), Amblyomma testudinarium (3 cases), Haemaphysalis longicornis (3 cases), and I. ovatus (1 case).

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