All species of the Scelionidae (Hymenoptera) are the egg-parasitoids of insects or spiders, and some of them are important for pest control. In Japan, 33 genera and 70 species of the family were recorded, but I presume a few hundred species are distributed in the country. The faunal survey of parasitic wasps in agricultural lands is important to utilize them for insect pest management and to investigate their biodiversity in "Satoyama". This is the first report on a generic composition of Scelionidae in the Tokai district, Japan. To collect insects, Malaise traps, emergence traps, and yellow pan traps were set in various farms, paddy fields, fallow fields, and riverbanks. These traps were also set in secondary summer-green forests to compare with the scelionid fauna in agricultural lands. In this study, about ten thousand specimens were examined, and 34 genera of Scelionidae were identified. The ratios of scelionid specimens to parasitic Hymenoptera in agricultural lands were larger than those in forests. The number of genera in agricultural lands was more than that in forests. Moreover, most of genera caught in agricultural lands held a lot of individuals. Therefore, the biodiversity of Scelionidae in agricultural lands is not less than that in forests. It is assumed that the richness of Scelionidae in agricultural lands is caused by the abundance of grasshoppers and crickets, which are the hosts of most of Scelionidae.

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Life cycles of two aphelocheirid species, Aphelocheirus vittatus and A. nawae, were investigated in Kinki district, Honshu, Japan, from 1996 to 1999. Aphelocheirus vittatus, widely distributed in Kinki district, is estimated to be univoltine in middle reaches of the Kamo River, Kyoto Prefecture, but in upper reaches of the river it may take two years to complete its life cycle. Aphelocheirus nawae, only known currently from the Muko River, Hyogo Prefecture, in Kinki district, is also revealed to have a one-year life cycle in middle reaches of the river. The adults of these 2 species are estimated to live for at least one year and females lay eggs from spring to early autumn. Based on the laboratory rearing, the effective cumulative temperature was 1,789 degree-days(dd) (developmental zero: 10.2℃) for development from oviposition to adult emergence in A. vittatus, and 2,000dd (8.2℃) in A. nawae, respectively. These two species inhabited fast flowing and oxygen-rich waters of pH 7-10. They were also observed to live on a sandy river bed scattered with gravels (cobbles), and partly with some submerged plants which may provide shelters or habitats for benthic invertebrates possively preyed on by these bugs.

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Feeding preference of the proturan species Nipponentomon nippon (Yosii) was studied under laboratory conditions on three pathogenic fungi, Fusarium oxysporum Schlecht.: Fr., F. solani (Mart.) Sacc. and Cylindrocarpon destructans (Zinssm.) Scholten, and one saprotrophic fungus, Pestalotiopsis sp. N. nippon feeds on all of these fungi indiscriminatingly, although P. sp. is not a preferred food for the fourth instar larva. Some new features of its feeding behavior, including the restriction of "pump" movement in the abdominal segments VIII-XII during the feeding, are described. It is observed that N. nippon feeds on baker's yeast in a mushy state. This observation suggests that its feeding habits also involve "suspension feeding" reported in the collembolan species.

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Pupation of the three-spot grass yellow, Eurema blanda arsakia (Fruhstorfer), on Cassia surattensis was observed in Ishigaki Island, Japan. Larvae showed marked gregariousness in all stages and the strong negative geotropism and the agressive behaviour against physical contacts in the wandering stage, so that almost all of the larvae pupated in rows along the underside of twigs of the canopy whose leaves had been entirely fed on. Although the mass of the brown pupae was very conspicuous and looked like plant seeds as a whole, almost all of the pupae were not attacked by birds or other predators, and adults emerged successfully about one week after. In the laboratory, the soldier bug, Eocanthecona furcellata, attacked the larvae similar to other non-toxic lepidopterous larvae, suggesting E. blanda is edible also for birds. It is inferred that the pupae of E. blanda collectively mimic some kind of plant parts in a group to avoid predation by birds.

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