Decrease of catalase activity in dead body samples of Drosophila flies occurred during a quick test for their catalase activity in hydrogen peroxide solution. The activity largely or completely disappeared within four to six hours of immersion of the insects in the test solution. Two or four immersion times of 15 minutes (total 30, or 60 minutes) decreased catalase activity more strongly than a single immersion of 30 or 60 minutes in the solution. Practical application of this quick method, therefore, should be limited to the first immersion treatment of samples in test solution.

View full abstract

Wing type pheromone trap of Indian meal moth has been used effectively for early detection at food processing plants, warehouses and grain storage facilities. Two tests were conducted to reveal the relationship of the trapped number of moths and hatched moths from breeding cages in a 30m³ room. (1) For 12 days, 15-80 moths (sex ratio unidentified) after hatched 0.5-1.5 days were released and captured by pheromone trap every day. An average 31.0% of the Indian meal moths were captured, and 58.4% of moths had died on the floor. (2) Indian meal moths (sex ratio identified) were released and captured for 3-5 days. From 5 trials, 44.3% of the released moths were captured and 55.7% died. The trapping rate of males was 57.6%. The reason for the high mortality rate of moths seemed to be the high temperature (high 40-low 23℃) in the room in summer.

View full abstract

[in Japanese]

View full abstract

The purpose of this study was to elucidate the mechanism by which the Indian meal moth, P. interpunctella, invaded wrapped dried figs and to study its biology on dried figs. Two film-wrapped dried figs were placed in a plastic container (15 cm in diameter, 6 cm deep) together with 2 mg of eggs and 10 last-instar larvae (20 days old) of P. interpunctella, respectively. The plastic containers were kept at 24±1℃, 70%RH and 16L8D. The number of invading larvae and newly emerged adults from the dried figs were recorded. Last-instar larvae could not invade the dried figs covered with wrapping film, whereas newly-hatched larvae could. It appears that newly hatched larvae invaded the dried figs through gaps in the wrapping film. The developmental period from first-instar larvae to adults of P. interpunctella was found to be 63.8±3.5 days (males, N=12) and 69.6±3.9 days (females, N=12) at 24±1℃, 70%RH and 16L8D on dried figs. The adult emergence rate was 83.3% in this experiments.

View full abstract

Mosquitoes were collected in Yokohama to elucidate the seasonal and local distribution, as a part of researches to survey the invasion of Yokohama by West Nile virus. CDC light trap combined with dry ice were settled to gather adult mosquitoes in each of 18 parks in 18 wards, two parks and two public institutions in the harbor area during the period from June to October, 2004. The total number of mosquitoes captured was 9,184, and they were divided into 6 genera, 12 species. The dominant species captured were Aedes albopictus (51.2%), followed by Culex pipiens complex (37.1%) and Ochlerotatus japonicus (8.0%). Culex pipiens complex was observed at each of 22 points, throughout the research period, but number of individuals exceeded in harbor area. On the other hand, Aedes albopictus and Ochlerotatus japonicus were collected mainly in parks of 18 wards.

View full abstract

[in Japanese]

View full abstract