Hybridization of Papilio helenus L. female and P. polytes L. male was studied. By hand-pairing it was possible to obtain hybrids between P. helenus and P. polytes. 15 male and 14 female hybrids were obtained in this investigation. The male hybrids were intermediate in appearance between two parental forms. Two female forms appeared among the hybrids. These forms were 8 cyrus-like (non-mimetic) form and 6 polytes-like (mimetic) form. The brood of P. polytes included two forms in female, f. cyrus and f. polytes in breeding the offspring.The gene controlling a mimetic form derived from P. polytes appeared in hybrids.

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On the basis of two males, an interesting new species having white forewing with broad fuscous lines, Mythimna (Mythimna) leucomelaena, is described from Papua New Guinea. The male genitalia of a similar species, Mythimna (Mythimna) tessellum (Draudt, 1950) known from China, are described also.

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A new genus, Gasterostena gen. nov., and two new species, viz. Gasterostena vietnamica sp. nov. and G. ikedai sp. nov. are described and figured from Vietnam.

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To understand the mortality rates and associated factors of overwintering larvae of the nymphalid butterfly, Sasakia charonda, we counted the number of dead larvae in the following categories of plots on the floor of a coppice from late November to the end of March; plots covered with mesh nets to prevent predation by natural enemies, a plot where fishing sinkers were put on dead leaves used as an overwintering site by larvae to prevent the leaves from being moved by any physical factors such as wind, and a control plot. To estimate the moving distance of dead leaves used by overwintering larvae, we put lead sinkers of the equivalent weight of one, two, or three larvae on dead leaves, which were marked on one side with paint, and set on the floor of the coppice in late November. Then the distance the dead leaves moved was measured at the end of March in the following year. To reveal the cold hardiness of the larvae during the first half of the overwintering season, the larval survival rates when the rearing temperature was lowered from 5℃ to 0℃, -5℃ and -10℃, gradually or rapidly, were investigated. To estimate the effects of frequency of water supply to the dead leaves used by larvae on larval survival, the survival rates were researched by varying the water supply, i.e. supplying water every day, once in four days, seven days, fifteen days, thirty days, or not at all. From these results, we examined the mortality factors of the larvae of S. charonda during overwintering.

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As an incipient step to clarify gall-feeding habits in Lepidoptera of Japan, field sampling of three distinct types of galls in addition to field observation was conducted in the Kinki district, central Japan. The collected galls were reared in the laboratory to examine cecidophagous lepidopteran fauna. 1) In spinous twig-galls on Quercus acutissima (Fagaceae) trees by the gall wasp Trichagalma serratae (Ashmead) (Cynipidae, Hymenoptera), over half of the gall clumps (58.3-100%) were attacked by lepidopteran larvae. Four lepidopteran species, Characoma ruficirra (Hampson) (Noctuidae), Andrioplecta pulverula (Meyrick) (Tortricidae), Anatrachyntis japonica Kuroko (Cosmopterygidae) and Hypatima sp. (Gelechiidae), eclosed from the galls. The latter two species are first records from plant galls. A. japonica larvae fed on the lignified gall tissues and attacked larval cells of the gall wasps. Whether the larva of Hypatima sp. fed on the gall tissues or not was unclear. 2) From oval stem-galls on the herb Achyranthes japonica (Amaranthaceae) by the gall midge Lasioptera achyranthii Shinji (Cecidomyiidae, Diptera), Amaya stellata Butler (Noctuidae) larvae were found. A. stellata larvae fed on the epidermis of the galls, with infestation rates being only 0-3.5%, and therefore little affected gall midge larvae. 3) From spherical fruit-galls on the liana Ampelopsis brevipedunculata (Vitaceae) by the gall midge Asphondylia baca Monzen (Cecidomyiidae, Diptera), Nippoptilia vitis (Sasaki) (Pterophoridae) adults eclosed. A N. vitis larva could complete its growth in one gall. When larval attack was prior to eclosion of the gall midge, the midge larva died of the destruction of the gall by N. vitis. The infestation rate by N. vitis was 52.9%.

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Larvae of the satyrine butterfly Lethe dina feed on blades of bamboo grass Sasa veitchii var. hirsuta whose blades have a two-to-four-year life span. I studied age class preference by L. diana. Both current-year blades and blades from previous years were used as oviposition sites by adult L. diana and as food by larvae. The ratio of young to old blades used changed seasonally, and these ratios were consistent with the ratio of young to old blades in available bamboo grass bushes during each season, i.e. neither adults nor larvae showed a preference for any age class of blades. Larvae grew better when they were fed young blades compared to old blades, so the fitness of L. diana would increase if young blades were selected. It is thought that L. diana is not particular about leaf age because it cannot discriminate between young blades and old blades.

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In copulation, most Lepidoptera unite with their abdomens end-to-end, their heads pointing in opposite directions, and their forewings making slopes to both sides like a roof. We call it "roof type" copulation. However, the slope of the roof varies according to differences in length of the body and size of the wings. In a typical case "female's wings cover male's wings (FCM)" or conversely "male's wings cover female's (MCF)". In these cases, the female always occupies the upper side with her head pointing upward during copulation on inclined slope or vertical surface. We call this "female dominant (FD)". "Male dominant (MD)" is possible but very exceptional. Females always keep the position FD with very rare exception. In the case of wing arrangement, FCM is apparently dominant, but often MCF occurs under natural condition. We classify copulation in Lepidoptera, especially nocturnal moths, into five postures as follows: Subtype 1-Typical roof type (RT); Subtype 2-1-V-shaped posture (VSP); Subtype 2-2-Face-to-face posture (FFP); Subtype 3-1-Horizontal wing posture (HWP); and Subtype 3-2-Butterfly posture (BP). All subtypes may be derived from a primitive RT; Subtype 1 is the true RT in the strict sense. In Subtype 2, the heads of both sexes point upward when resting on inclined slope or vertical surface. VSP is V-shaped copulation, in which the male approaches the female laterally, hence their bodies make a V shape. In FFP, the male later on moves to his partner's ventral side and assumes face-to-face posture. In HWP, as the wing size becomes larger, and the abdomen size becomes slender, the slope of RT is reduced gradually, finally becoming almost horizontal. If during copulation, the pair's wings are held horizontally, we call it HWP. And in BP, the pair's wings are held upright on their backs.

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