The change of activity associated with food deprivation in non-diapausing Cletus punctiger adults was studied with an actograph equipped with an infrared photo-electric switch. The activity was recorded and expressed as the number of intercepts of infrared beam. When the food was continuously available, the daily activity was low and there were few changes depending on the age. Also differences between the sexes were not conspicuous. The daily activity increased in the females soon after deprivation of food and it decreased soon after the food supply was resumed. This phenomenon was remarkable in the females more than 20 days after adult molt. The longer the time interval after food deprivation, the higher the activity in the photophase, especially in the latter half of the photophase. The activity in the scotophase was always low regardless of the presence of food.

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Glycoproteins were extracted and partially purified from heads of adults of the silkworm, Bombyx mori. Physiological activity of the glycoproteins was also examined using five different bioassay systems. The yield of the glycoproteins separated by ConA-Sepharose 4B affinity chromatography was about 43mg from 120g of the starting materials. The molecular weights of the main glycoproteins were 15, 000, 30, 000 and 50, 000 as determined by gel-filtration on Sephadex G-75. Neurohormonal activities (prothoracicotropic hormones, diapause hormone, eclosion hormone) were not detected in the glycoprotein fraction. Effect of the glycoprotein fraction on the ovarian development of isolated abdomens was investigated, but no gonadotropic action could be detected: the ovaries grew only when 20-hydroxyecdysone was injected into the isolated abdomens.

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Laboratory tests for the detection of egg, larval and pupal cannibalism by the larvae of Coccinella septempunctata bruckii were carried out. When no aphids were supplied, most of the eggs were attacked by larvae in each instar, and most of the first and the second instar larvae molted to the next stages only with eggs. When an adequate number of aphids was supplied, only the first and the second instar larvae attacked a few eggs, and the third and the fourth instar larvae never attacked eggs. When no aphids were supplied, larval cannibalism occurred frequently in the second, the third and the fourth instar larvae, but most of the first instar larvae were starved to death or attacked by other instar larvae, whereas, when an adequate number of aphids was supplied, larval cannibalism was minimal. Pupal cannibalism by the larvae did not occur except in one instance when no aphids were supplied.

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The apple snail, Pomacea canaliculata LAMARCK, was introduced into Japan in order to rear it for food. Since 1984, however, the snail become harmful to young lowland crops in the Kyushu district, in southwestern Japan. When irrigation water is removed from the paddy fields in autumn, the snails burrow into the ground at a depth corresponding to the height of their shells. In late December, 3 months after the removal of irrigation water, the survival rate of the snails buried underground was 80% or more, whereas that of the snails under dead grasses was about 40%. This difference was probably due to the difference in the degree of exposure to low temperature. The mortality of the overwintering snails gradually increased from mid-winter (January) to late winter (March). Snails kept in storage incubators at 0, -3, and -6°C died within 25, 3, and 1 day, respectively. These results suggest that in the temperate zone, the survival of overwintering snails is strongly affected by low temperatures below 0°C. Based on the field investigations made on April 19, the survival rate of the snails was about 20% in a nonirrigated paddy field but only 5% in a dry irrigation canal. Young snails with a shell height of 2-3cm seemed to have a greater tolerance to low temperatures compared with the mature ones with a size larger than 3cm. After transplanting of rice, overwintered snails gradually appeared on the surface of the field for a period of 1 month. In the field where rice and wheat are cultivated in succession, 4.1-6.8% of the snails which had been detected in the autumn were observed 17-28 days after transplanting of rice in mid-June.

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Three species of Henosepilachna beetles feeding on wild native host plants in fields were reared on cultivated potato plant under laboratory conditions. The rate of increase (=number of newly emerged females produced by an overwintered female) of H. vigintioctomaculata reared on potato was about 6-fold higher than that of the individuals reared on a wild host plant, Scopolia japonica, mainly due to the increase of the number of eggs laid per female. The rate of increase of H. niponica reared on potato was about one-sixth lower than that of the individuals reared on a wild host plant, thistle, due to the decrease of both the number of eggs laid per female and larval survival rate. The rate of increase of H. yasutomii reared on potato was about twofold higher than that of the individuals reared on wild host plants, blue cohosh and S. japonica, due to the increase of the number of eggs laid per female. There were no clear differences in the larval survival rates of H. yasutomii among food plants. Furthermore, the author attempted to determine whether these three wild populations of Henosepilachna beetles were able to switch from wild native plants to cultivated potato.

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To analyse the effect of fertilization of grass on the survival and growth of the armyworm, Pseudaletia separata WALKER, and the interaction between armyworms and a wolfspider, Pardosa laura KARSH, field and pot experiments were carried out. Fertilization of orchardgrass, Dactylis glomerata L., increased the nitrogen contents, height and density of the grass. Survival and growth rate of the armyworms increased with increasing grass nitrogen contents due to fertilization. Although the armyworms occurring on non-fertilized grass walked about more actively than those on fertilized grass, the larval mobility had little effect on the degree of wolfspider's predation. The wolfspiders on non-fertilized grass preyed on a larger number of larvae of the armyworm than those on fertilized grass. For the same level of fertilization, the wolfspiders occurring on short or sparse grass preyed on a larger number of larvae than those on tall or dense grass. These results suggest that fertilization of grass increases the survival rate of the armyworm due to the increase of the grass nitrogen contents as nutrient for the larvae, as well as the increase of grass height and density which interfere with the wolfspider's predation.

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The adult emergence of the box-tree pyralid, Glyphodes perspectalis collected from four localities in Japan showed the geographical cline for overwintered generation. The Tokyo-Chiba population had three generations per year, and the adults appeared from mid-May to late June, from late July to late August and from late August to mid-September. The theoretical developmental zero and the total effective temperature for development in the summer generations (second and third broods) were 11.6°C and 55.0 day-degrees for the egg period, 10.1°C and 365.0 day-degree for the larval period, 12.0°C and 128.9 day-degrees for the pupal period and 8.1°C and 38.5 day-degrees for the preoviposition period, respectively. Thus G. perspectalis required about 610 to 620 day-degrees above 10.5°C to complete a summer generation. In the overwintered generation (the first brood), on the other hand, these values were 10.1°C and 238.1 day-degrees for the larval period and 10.9°C and 142.0 day-degrees for the pupal period, requiring about 350 day-degrees above 11.0°C for the first adult emergence.

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The content of calcium in the A-, H-, F- and L-soil layers was high, but that of phosphorus in the soil layers was low. While the content of nitrogen in the soil layers decreased in the lower layers, the sodium content tended to increase. The content of the six elements in plants was N>K>Ca>Mg>Na>P, in the descending order. The content of Ca, Mg, and Na in the forest ecosystem of Hokkaido was lower than that in Oita Pref. The content of P and N increased with the ecological niche of the food chain, while that of K and Mg tended to decrease. The content of P and N in the herbs of the damp plains was higher compared with that of the grassland in Oita Pref. The content of P, N, and K in Pteridophyta of the grassland was higher than that of the damp plains. BHC residues in the forest ecosystem of Iwamizawa decreased with the ecological niche of the food chain.

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The content of elements in the H- and F-soil layers (cryptomeria pure forest and cryptomeria, white cedar, andromeda and hydrangea mixed forest) was in the order of calcium>magnesium>sodium>potassium>nitrogen=phosphorus. On the other hand, the content was in the order of K>N>Ca>Mg>Na=P for the herbs; N>Ca>K>Na=P for the trees. However, the content of N, K, P and Na (the content of each element was almost the same) was higher than that of Ca and Mg for insects. The content of N, Mg and P in the herbs near the craters was high compared with that in areas at a lower elevation the amount of BHC residues decreased in the order of L-layer>F-layer>H-layer and the amount of BHC residues in trees decreased near the creaters.

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Histological studies of pea-aphid embryos and larvae showed that the wing buds and myoblast of muscles were present in all the embryos as well as the 1st and 2nd instar larvae. In the 3rd instar larvae, wing buds and myoblast of muscles were developed into the alate form. Indirect flight muscles in alate virginoparous females began degenerating at the start of reproduction. In the alate males, the indirect flight muscles did not degenerate even up to 49 days after the final moult. During 1 to 9days after the final moult, the flight activity in the alate virginoparous females was very high but it decreased at the start of the reproduction period. In the alate virginoparous females which lived for about 10 days after the final moult under starvation conditions, the indirect flight muscles did not degenerate and they flew very well throughout their life period.

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Development of larval ovaries in the brainless male pupae of the silkworm, Bombyx mori, was induced by the injection of 20-hydroxyecdysone or prothoracicotropic hormone. Number of eggs which developed in the brainless male pupae ranged from 55 to 57. The eggs in the brainless male pupae developed without accumulation of vitellogenin which was normally formed in the eggs produced by the females. It was shown that ecdysteroids or prothoracicotropic hormone and pupal environment are necessary for oogenesis to take place.

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