The insecticidal action of phytoecdysones, i.e. ponasterone A, ecdysterone, inokosterone and cyasterone was investigated for various insects. The high insecticidal action was found when phytoecdysones were acted on the body surface of Chilo suppressalis larvae, Pluttella xylostella larvae and Culex pipiens molestus larvae. However, Musca domestica larvae and Pieris rapae crucivora were tolerant against the substances. The insecticidal acitivity for the rice stem borer larvae varied with the developmental stage. That is, the nondiapausing final instar larvae were more sensitive against the phytoecdysone than the 3rd instar and the diapausing larvae.

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From laboratory rearings at constant tempertures and the analysis of light-trap records, it was ascertained that the relation between temperautre and velocity of non-diapause development of Hyphantria cunea was linear between 14°C and 26°C. The calculated threshold of development was about 10°C for completing the whole immature period, but the values for egg and pupal stages were somewhat higher. The thermal constant was 750 to 850 day-degrees to complete non-diapause development. H. cunea is, however, considered to be practically unable to complete its life cycle at 12°C because of high mortality. Temperatures near 30°C are also unfavourable for the development. Short days that induce pupal diapause may have a little effect on the relation between temperatuers and larval development. It was sugested that hot summer in the middle part of Japan would be an unfavourable condition for the life of Hyphantria cunea.

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The author has already demonstrated the exstence of the attractive factor for mosquito oviposition in the pulluted field water. The attractans were separated by gas-chromatography and preliminary attempts of the chemical identification were made. Four compounds from the neutral fraction of the ehter-extract were found to be attractive, while, the phenolic, basic and acidic fractions were highly stimulative for mosquito oviposition. Two out of the four attracrive compounds were found only in the summer waters when Culex pipiens pallens bred aboundantly. Further bioassay on the semiquantitative bases revealed that these four compounds were effective to the extremely low concentrations to C. p. fatigans as well as C. p. pallens but not to Aedes aegyti.Using the infrared and mass spectroscopies the chemical structures of the three attractive compounds were presumed to be 2-butoxyethanol, a saturated open chain ketone and a toluic acid ester with a fairly long unsaturated alcohol, repsectively. The attractiveness of the first compound commercially obtained was, however, controversial.

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Electrophoretic separation in agar gel on various enzymes of silkworm tissues was carried out. The intestine had generally intense bands of various enzymes moving toward the anode. Fat body, integument and ovary showed active bands of some enzymes such as malate dehydrogenase and glucose-6-phosphate dehydrogenase. However, clear band could not be detected in the blood. Malate, α-glycerophosphate, and lactate dehydrogenases, leucine aminopeptidase, proteinase and alkaline phosphatase occurred in multiple forms, whereas only one positively migrating band was detected in silkworm tissues for isocitrate and glucose-6-phosphate dehydrogenases. Regarding zymograms of extracts from intestine, the staining intensity of dehydrogenating enzymes generally decreased with the progression of development. On the other hand, in zymograms of hydrolytic enzymes the high staining intensity at the last larval stage fell at the prepupal and early pupal stage and rose again at the middle pupal stage.

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In the cabbage bug the kind of enzymes in the salivary gland, the effect of hydrogen-ion conentration on salivary amylase activity, and the developmental changes in relation to the appearance of salivary protease and amylase were studied in vitro. Amylase and pectinase activities were found, but neither protease, invertase, α-glucosidase nor celulase was detected late in August. The salivary amylase was active within the range of pH 5.0∼8.0 with an optimum activity between 6.0 and 7.0. Its activity was very low in the second instar nymph and relatively high in the third, fourth, and fifth instar nymphs, reaching a miximum at the fourth instar. In the hibernated adult the activity was relatively high late in May and thereafter it lowered gradually. Late in June it was rather lower than that of the nymphs from the 3rd to 5th instar and similar to that of adult of the first generation obtained late in August. No salivary protease was detected at any developmental stage.

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In the pervious paper (MIYASHITA, 1968), it was reported that the daily food consumption of Lycosa T-insignita during the last instar and adult stages showed great changes with advanes of developmental stages, age in days, and reproductive activities. The present experiment was conducted in order to ascertain whether or not the daily food consumption in another species, Lycosa pseudoannulata, also changed with the similar pattern observed in L. T-insignita.

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