The acceptability and the toxicity of four rodenticides and quinine hydrochloride in albino rats were evaluated using the modified Osaka University Type Skinner-Box with two food-levers. The total food-lever pressing activity (counts and time) in poison baits containing thiosemicarbazide, bisthiosemi, phenylthiourea and sodium monofluoroacetate decreased considerably, whereas that in the bait containing quinine hydrochloride increased. In the case of quinine hydrochloride the switch of the lever already preferred during the control period occurred during a preference test to plain and poison baits. In the case of other poisons, however, such phenomena did not occur. All the rats tested for four rodenticides died but other rats tested for quinine hydrochloride survived. As the acceptability of poison baits was evaluated on the basis of integrated data on the lever pressing activity, the change in lever preference to one pair of levers, the amount of poison baits eaten in the old and the modified types of the Skinner-Box, mortality, speed toxic action, and gustatory effectiveness, acceptability of poisons employed is evaluated as follows: fair-MFA, BS and TSZ, moderate-PTU, and low-quinine hydrochloride.

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In November, 1983 a large number of exotic millipedes, Chamberlinus hualienensis Wang, swarmed on the surface of the soil at Yagibaru, Kitanakagusuku-son, located in the central part of the mainland of Okinawa. The outbreak was the first case in Okinawa and the species was a new species of milliped found on fauna in Japan. Wang first described the species collected from Haulien, Taiwan. The outbreaks were observed twice a year. Larvae occasionally occured from April to June, which fell in the rainy season, and the adults swarmed constantly from October to December for mating. Population densities during the outbreak were estimated at 100,000〜1,000,000 millipedes which swarmed at night. Since 1983, the exotic millipede has expanded its distribution from 1 area to 74 areas, covering 22 son (villages) of which 33 son where on the mainland of Okinawa.

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Helminthological survey on roof rats, Rattus rattus, was carried out o on rats captured from urban buildings in Tokyo. Helminths were detected from 84 out of 200 roof rats autopsied, and seven species were obtained from the infecected rats, including the nematodes of Capillaria hepatica, Nippostrongylus brasiliensis, Protospirura muris, Syphacia muris, and the cestodes of Cysticercus fasciolaris, Hymenolepis nana and H. dimininuta. A fragment of German cockroach, Blattella germanica, which may be an intermediate host of P. muris, H. nana and H. diminuta, was detected in the small intestine of a rat. Plant materials and animal materials in stomach contents of roof rats captured in a building located Shinjuku in Tokyo, were 65.0% And 17.2% in volume, respectively. Main plant materials were cereals and their products.

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[in Japanese]

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Contact effectiveness of insecticide often fluctuates due to the characteristics of the substrate treated with insecticidal formulations. The effect on the toxicity of two insecticides, fenitrothion and permethrin, applied on the different substrates were evaluated against female adults of the German cockroach, Blattella germanica (L.) by continuous contact method. Six substrates including plywood, cotton cloth (adhered on plywood), and blicks as the porous materials and stainless steel, tiles, and varnished plywood as the non-porous ones were chosen for this purpose. As a whole, both insecticides treated on the non-porous substrates showed the higher effectiveness than those treated on the porous ones. However, the effectiveness of fenitrothion seemed to vary greatly among the substrates when compared with permethrin. In the tests with permethrin, the residual effectiveness increased with the day's lapse, presumably due to a blooming effect of the insecticide. Repeated use of insecticidal residues reduced the effectiveness more in the non-porous substrates than those in the porous ones. Decreasing volume of the spray from 50ml to 25ml per square meter did not affect the effectiveness on the non-porous materials.

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Influence of the position and number of pheromone traps (NEW-SERRICO, Fuji Flavor Co. Ltd.) on the number of adult cigarette beetles, Lasioderama serricorne F. was studied in a flour mill to evaluate the effectiveness of the use of the traps for the control of the beetles. A pheromone trap was placed at a height of 1.5m every 50m² in 1989. Two traps were placed every 30m² in 1990 at a height of 1.5 and 3.0 in the same site, respectively. The number of adults captured was counted every two weeks and the traps were renewed every month. Fewer adults were captured per trap in May and June 1991 than in 1989. The number of adults captured by the traps at a height of 1.5m was correlated with that at a height of 3.0m (r>0.916, α=0.01). On the other hand, the number of adults captured varied markedly among the sites. These results indicate that pheromone traps can be used to reduce the population size at least in the early period of occurrence of the cigarette beetles and that the effect of the horizontal position of the pheromone trap on the number of adults captured is more significant than of the vertical position.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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