Oxygenated terpenes separated from healthy Pinus densiflora wood are attractive to the cerambycid beetle, Monochamus alternatus, while the healthy pine is unattractive to it. Thus, the attractiveness of the pines appears to be masked by an unknown substance occurring in the healthy pine. A key compound (-)-germacrene D, was isolated from the steam distillate of healthy pine leaves by reduced-pressure distillation, HPLC and TLC. In an olfactometer chamber, the oxygenated terpenes elicited flight response in the female beetle, but (-)-germacrene D in combined use diminished the attractiveness. The inhibitory activity was also confirmed in a linear tube olfactometer. The locomotory response of the female was released by a mixture of (+)-juniperol and (+)-pimaral-attractants isolated from the healthy pine. However, the female ceased her locomotory movements when (-)-germacrene D was added to the attractant odor. Therefore, (-)-germacrene D functioned as a ;masking substance, i.e., an agent inhibiting the locomotory movements toward the attractant source.

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The effects of varying water contents in sawdust serving as ovipositing medium on the oviposition factors of the cupreous chafer, Anomala cuprea, were investigated at 25°C and 16L-8D photoregime under laboratory conditions. the proportions of sawdust to water were adjusted to 1:0.5, 1:1, 1:2, 1:3 and 1:4 by weight. the optimum condition for maximum lifetime fecundity, short preoviposition period, long oviposition period and long adult longevity for both male and female adults was 1:2. A significant correlation between lifetime fecundity and longevity of the females was observed at 1:0.5 and 1:1 and also between lifetime fecundity and oviposition period at 1:1 and 1:3. Lifetime fecundity was not correlated with preoviposition period at any of the water contents tested. Females were capable of egg laying until their death, but the oviposition time interval could not be ascertained at different water contents. Hatchability of the eggs laid at each water content was more than 90% except at 1:0.5. There was no significant difference in the daily food consumption by adults at different water contents. Moreover, the amount of food consumed each day was more or less uniform throughout the lifetime and the insects were capable of feeding until death irrespective of water content in the sawdust.

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Different wing-forms (brachypters and macropters) of the whitebacked planthopper, Sogatella furcifera, were selected for 12 generations and correlated responses of several life history traits, wing length, and flight propensity to this selection were examined. A positively correlated response to wing-form selection was observed in nymphal developmental time, but no consistent response was observed in either fecundity or adult longevity. a significant reduction in forewing length was detected in response to selection for brachyptery. The flight propensity of macropters in the brachypterous line measured by the flight mill technique was significantly lower than that recorded in the control line. These results suggest that selection for brachypetery not only influences the incidence of brachypters but also acts to decrease the forewing length and flight propensity of macropterous individuals of the brachypterous line.

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In a 3-min methanol wash of field-collected millipede, Nedyopus patrioticus patrioticus (ATTEMS, 1898), the following four components were identified by GLC, HPLC, GC/MS and NMR as possible defense substances: benzaldehyde, phenol, p-cresol and mandelonitrile, among which p-cresol was the major component in adults (282 μg on average in males and 300μg in females), and was found in trace amounts (0.2 μg on average) in the nymphal stages. This is the first case among Polydesmida millipedes whereby a large amount of -cresol was contained as the adult specific compound and phenol as the female biased one. Hydrogen cyanide was also detected from this species.

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When larvae of the Akita strain (bivoltine, 39°N) of Chlorops oryzae MATSUMURA were reared on rice-plant seedlings younger than the 4 leaf stage under LD12:12 or 14:10, most pupated 25 days after hatching. Under long day conditions (LD15:9), by contrast, most larvae failed to pupate and remained in the first or second larval stage 25 days after hatching when reared on 7-leaf-stage seedlings. On the other hand, larvae of the Aichi strain (trivoltine, 35°N) reared on rice seedlings of the 5 leaf stage or younger grew fast under both short and long days. Larval development was delayed under an intermediate day (LD14:100. This suppression of larval development in the Aichi strain became more marked as the rice plants aged. These results suggest that larval development in the first generation of the bivoltine strain and the second generation of the trivoltine strain is retarded by photoperiodic and host-plant conditions. This retarded development in the early larval stage may be regarded as diapause mediated by food plant and photoperiod.

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Pseudoregma bambucicola, an Asiatic eusocial aphid, shows a typical life cycle of host-alternating aphids in Taiwan. It sexually reproduces on primary host trees and parthenogenetically produces offspring including sterile soldiers on secondary hosts. However, in southern Japan where this aphid species is thought to have been artificially introduced with secondary host plants and where there are no candidates for primary host plants, the apterous virginoparae propagate parthenogenetically throughout the year on the secondary host, still producing numerous alate sexuparae in autumn. In the present study, I collected 18 wing-padded aphids in winter and the following spring and, by rearing them, ascertained that these abnormal individuals grew not to sexuparae but to adult virginoparae which produce "normal" first-instar larvae and soldiers on the secondary host. This suggests that natural selection favors some wing-padded aphids to abandon flight probably due to the high mortality of alate immigrants, supporting the idea that the alates may play no significant role but may be produced by phylogenic inertia in Japan.

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Oxya chinensis formosana from Okinawa Is. responded to photoperiod in various ways at 25°C. The nymphal duration was shorter at LD12:12 than at LD14:10. The number of nymphal stadia was 5 or 6 in the male and 6 in the female at LD12:12, but 6 in the male and 6 or 7 in the female at LD14:10. Females reared at LD14:10 throughout post-embryonic development oviposited later than those reared at LD12:12 throughout the study and those transferred from LD12:12 to LD14:10 (or vice versa) on adult emergence. Some eggs entered diapause when incubated at 25°C irrespective of the parental photoperiods. the incidence of egg diapause was lowered by an increase in photoperiod from LD12:12 to LD14:10 on adult emergence. These results suggest that a ;majority of the population have a heterodynamic life cycle with a short-day type photoperiodic response controling both nymphal development and reproduction, and also with diapause in a portion of the eggs.

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Athalia japonica (Hymenoptera: Tenthredinidae) showed an intermediate type of photperiodic response curve for diapause induction, when stationary photoperiods were employed. Photoperiods ranging between LD 13:11 and 14:10 stimulated continuous development. Even under these photoperiods, however, more than one third of the individuals entered diapause at 20°C and 25°C. also, when field grown larvae which were expected to enter diapause were brought into the laboratory in October, many emerged instead of entering diapause. Therefore, the possibility that A. japonica uses changing photoperiod as a cue for a developmental program was examined. Insects exposed to LD 15:9, which usually induces 100% diapause, for the first 4 days, were transferred to LD 12:12, which also usually induces 100% diapause. They were kept under LD 12:12 till cocoon formation, at which time they were transferred to LD 16:8. This transfer resulted in the lowest rate of diapause ever observed in the laboratory. The transfer, however, had to be made early during the larval stage to avert diapause, and the effect gradually decreased with later transfer. Transfer in the reverse direction was not effective at all.

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Two liquid formulations containing Bacillus thuringiensis serovar japonensis strain Buibui toxin were evaluated in the field for control of Japanese and oriental beetle larvae. One formulation stopped in late sporulation phase where greater than 90% of the cells lysed contained free protein toxin crystals (parasporal inclusions) and live spores. A second formulation contained B. thuringiensis serovar japonensis strain Buibui toxin expressed in killed recombinant Pseudomonas fluorescens. both formulations demonstrated the ability to significantly reduce Japanese and oriental beetle larval populations in turfgrass compared to untreated controls. The B. thuringiensis formulation was more effective than the first prototype of the genetically engineered P. fluorescens, but the potential for development of this technology was clearly demonstrated.

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Unidirectional incompatibility is known in the kanzawa spider mite, Tetranychus kanzawai KISHIDA. Crosses between females from kudzu and males from either tea, pear or hydrangea were incompatible and resulted in no female offspring, while the reciprocal crosses were compatible and produced normal progeny with a female-biased sex ratio. Of these populations, the tea, pear and hydrangea populations were found to be infected with Wolbachia, which has been previously shown to alter reproduction in arthropods. Wolbachia was identified using PCR assays for a 770-bp fragment of the ftsZ gene and an 890-bp fragment of the 16S rDNA. Compatibility between females from the kudzu population and males from either of the antibiotic-treated tea, pear or hydrangea populations was not restored even when the latter were treated with tetracycline and rifampicin. PCR assays did not reveal any Wolbachia DNA in mites that were treated with antibiotics. Therefore, T. kanzawai appears to harbor a neutral strain of Wolbachia which does not cause the incompatibility seen in Drosophila spp.

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Three albino females were discovered in a field population of Panonychus osmanthi, the albinism being a result of spontaneous mutation. To determine the genetic control of the albinism, standard genetic crosses were conducted. Apparently the albinism was recessive to the normal pigmented trait and was under monogenic control. albino mites with reddish eye-spots were obtained when pigmented hybrid females obtained from crosses between the albino and normal strains were either kept virgin or mated to males with various phenotypes. The eye-spots of albino females were not passed onto the next generation irrespective of the male phenotype. These results suggested that some pigment precursor possessed by pigmented females is responsible for the appearance of the eye-spots. Hybrid females resulted in a reduction in hatchability in F₂ eggs and a distortion of the female: male ratio. These phenomena might be explained in terms of the difference in mortality between haploid and diploid eggs: i.e., crosses between hybrid females and pure albino males without eye-spots resulted in the death of about 50% of both haploid and diploid eggs, whereas crosses between hybrid females and either normal males or eye-spotted albino males resulted in the death of about 50% of haploid eggs but did not cause the death of diploid eggs.

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