|Budget Amount *help
¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1991 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1990 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1989 : ¥1,500,000 (Direct Cost : ¥1,500,000)
1. By the observations of the mating behavior of the Japanese beetle, Popillia japonica (P. j, ) and the yellowish elongate chafer, Heptophylla (H. 2), we recognized the sperm competition between adult males of these species, resoectively. Males of Pj. were often on guard of feamales long time from other males when male sex ratio was too high. 2. We found in some scarab beetls that a part of adult feamales could not fly because of lacking of their flight muscles that was flight muscle polymorphism. Females of H. p. which had not been the flight muscles utilized their fat bodies in their thoraxes for the development of their ovaries. 3. On the rearing of the soy bean beetle, Anomala rufocuprea (A. r.), in a laboratory, we could shorten their life cycle duration less than 1/2 times. We also obtained good results byusing the artificial diet to rear adults of this beetle. Furthermore we succeeded the larval rearing of H. p. by feeding with leaf litter and fresh carrot roots. 4. Existence of sex pheromone of virgin females of some scarab beetles such as lip., A. r. and the cupreous chafer, Anomala cuprea (A. c.) was investigated. As the results, males of the former two species were attracted to the females, but there was no evidence against A. c. 5. Effects of an insecticidal formulation of a entomoparasitic mould, Metarhizium anisopliae (M. a.) was examined against A. c. larvae under a laboratory conditions. The remarkable effect were recognized against eggs and 1st instar larvae. Also, A. c. larvae killed by Ma. had still strong infectivity after seven weeks. 6. Larvicidal effect of a entomogenous nematode, Steinernema kushidai (S. k.) against five species of scarab beetles were examined. As the results, S. k. could shown the effects on all of examined species. We also found that another nematode, S. feltiae had excellent control effect to the larvae of the scarab beetles by the mix treatment with chemical insecticides or surface active agents.