The dispersal 3rd-stage larvae (L_IIIs) of B. lignicolus began to occur after 3 to 5 months on the fungal mat of Botrytis cinerea without being subcultured and constituted almost 100% of the surviving nematodes after 10 months. However, extended monoxenic culturing of the nematodes brought about a decrease in the survivability under the starvation and consequently decreased the production of the L_IIIs. Addition of fatty extracts from larvae and pupae of a cerambycid beetle. Monochamus alternatus, gave rise to an increase in surviving nematodes and in the L_IIIs after being left without subculture. The molting of the L_IIIs in water to the dispersal 4th-stage larvae (L_IVs) was positively correlated to the developmental stages of the beetle at the collection time of worms. However, most of L_IIIs, which had been left in the pupal chambers for 20 days after the removal of the insects, molted into the prpagative 4th-stage larvae (L₄s), irrespective of the pupation of the insect. L_IIIs and L_IVs were both still viable after 100 days under starvation. The live L_IVs were recovered from dried cadavers of adult beetles after 6 months. The L_IIIs seem to be relatively better able to surive under starvation, whilst the L_IVs under dryness.

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Based on a logistic model of population growth and Poisson-binomial model for frequency distribution of matings between sterile and normal insects, a simple model was presented to simulate population processes under mass-relases of sterile melon flies. Constants used in the model were determined according to the results of population studies made in Kume Is., Okinawa. It was suggested that, under the conditions assumed here, a 2 : 1 ratio of mature sterile males and normal males in an isolated target area was enough to result in eradication of the melon fly within one year.

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Hunting spiders Oxyopes selatus and O. bodius are common in young pine plantations.The number of 3rd-instar larvae of Lymantria dispar captured by a spider was affected by the hunger of predator and the number of prey, but not exceeded three in 10 days. In a pine plantation, one spider killed less than one 3rd-instar larvae of L. dispar. No aggregation to prey densities was observed. The number of spiders in pine plantations was seemingly determined through dispersal, predation by natural enemies and other factors, and it was not sufficiently large to cause high mortality in macrolepidopterous caterpillars. The role of the spiders in determing the density of the caterpillars was considered as follows. (1)Mortality caused by the predation was negligibly small and inversely density-dependent.(2) Though, when small number of caterpillars was there on a tree, it would be exterminated on the tree. (3) And as the result, the distribution pattern of the caterpillars seemed to become contagious. (4) The spiders, however, could not control the local occurrence of the caterpillars

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A diet consisting of drone honey bee brood provided an adequate nutrition for larvae of an aphidophagous coccinelid, Harmonia axyridis PALLAS. These beetles, however, could not grow on the diet lacking a fraction which is hot-water soluble, cationic and not adsorbed on active charcoal. A defined mixture of minerals could substitute for this fraction. The mineral requirements for the larval growth of the beetle wre thus elucidated and shown to be substantial, especially for potassium.

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A. glomeratus obtained from P. rapae crucivora collected in Kyoto cannot develop in P.melete because of the hemocytic defense reaction of this host. Experiments were conducted to find out whether mass oviposition can weaken this defense reaction. In the experiments, larvae of P. melete were attacked by several parasitoid females at a time. It was found that mass oviposition did not always weaken the reaction, but parasitoids egressed from a few host larvae. These parasitoids were used in a second experiment to determine if they could successfully parasitize P. melete larvae.Parasitoids obtained from A. crataegi adherbal collected in Sapporo can develop in P.melete. One generation of these parasitoids were raised in P. melete and the same experiment was carried out to test how successfully they could parasitize P. melete larvae.The results fail to support the assumption that rearing the parasitoids in P. melete larvae has the effect of selecting a strain which can develop in P. melete.

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Investigation was made at two groves (Kasedo and Kawatoko) of "Kuroshima-mikan", a native citrus on Nagashima, Kagoshima Prefecture, in order to determine the most desirable relation between the pests and their predators in citrus groves.Of the predators, Saula japonica feeding on the arrowhead scale, citrus red mite, etc. was the largest in number and Pseudoscymnus hareja feeding on the arrowhead scale, aphids, etc.was next. These two species amounted to about 60% of the total. Of the pests, the arrowhead scale was dominant and there were many species, but none whose population was noticeably high. The population of citrus red mite was far below the control threshold.The population of Saula japonica was very high and that of Unaspis yanonensis was somewhat higher at Kasedo where the grove was darker, not windy, and humid. But the populations of some predators were higher at Kawatoko which was lighter, windy, and dry. Thus both the pest and predator seem to choose a habitat condition.The population of the arrowhead scale was higher at the grove of "Kuroshima-mikan"than at the orchard of natsudaidai cultivated and sprayed in Hagi; that of citrus red mite was far below the control threshold. The predator fauna was moer rich both in species and individual numbers at the grove of "Kuroshima-mikan"than at the orchard cultivated but unsprayed in Nago. The abundance of fauna seems to contribute to control the population of arrowhead scale below a certain point and to keep the citrus red mite at an extremely low density.

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Male-produced scents were analyzed, their function was studied, and mating behavior was described in Leucania separata. The male scents contained benzyl alcohol in high concentration until the third night after emergence. Five other scent components, including benzaldehyde, benzoic acid and n-butyl alcohol, were also detected. In tests in whcih hair brushes and antennae were excised and hair-brush pouches were sealed, no direct relation between the male scents and mating behavior was found. Similar biological results were also obtained for Mamestra brassicae.

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The eupyrene sperm bundles and apyrene spermatozoa were ejaculated simultaneously into the copulatory pouch. The former were separated and took a curved shape at about 30 minutes after ejaculation and the latter shrunk immediately after ejaculation. The seminal receptacle consists of two chambers; one is termed the large lobe to which the accessory gland belongs and the other which protrudes from the large lobe is the small lobe. The eupyrene spermatozoa mainly migrated from the copulatory pouch into the large lobe, while the apyrene spermatozoa mainly migrated into the small lobe through the large lobe forming several masses. The masses of apyrene spermatozoa dispersed soon after. As the degeneration of the apyrene spermatozoa in the small lobe gradually proceeded, the eupyrene spermatozoa in the large lobe migrated into the small lobe. When a considerable number of the apyrene spermatozoa in the seminal receptacle degenerated, the adult females began oviposition. The present observation suggests that the apyrene spermatozoa plays a certain benefical role to assist the eupyrene spermatozoa in the process of fertilization.

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When the 5th-instar larva of the silkworm, Bombyx mori L., was fed with methyl 6, 7-dioxo-5α, 10α-podocarpa-8, 11, 13-trien-15-oate (compound A-11), the instar period was prolonged and silk productivity increased. The relationship between the method of administration and the specific quality of cocoon were examined.

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Description of a newly discovered granulosis virus of the peach fruit moth Carposina niponensis and histopathological observation of the infected larva were reported in this paper.The oval capsules were approximately 480 nm long and 300 nm wide, while the virus rods were 265 nm long and 40 nm wide. Light microscopic observations of the infected larvae suggested that the fat body, tracheal matrix, Malpighian tubule, epidermis and midgut were the tissues susceptible to the virus. A cross-transmission test of the virus to larvae from four Tortricidae species, Adoxophyes sp., A. orana fasciata, Archippus breviplicanus, and Homona magnanima, was unsuccessful.

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