Five species of insects (Blattella germanica, Periplaneta fuliginosa, P. americana, Musca domestica and Megaselia spiracularis) were observed on the catalase deactivation with heating temperature and time passage. Additional tests were carried out on the same insects for 30 days of immersion in four kinds of liquids (10% sugar solution, 15% ethanol, soy sauce and vegetable oil). The experiment was carried out by a simple method of dropping 3% hydrogen peroxide on the crushed body. On the relation between heating and the catalase activity, the five species of insects retained the activity after heating at 65℃ for 60 minutes. Catalase activity was easily lost by heating at 80℃ in B. germanica, 90℃ in P. fuliginosa, and 90℃ in M. domestica. On the other hand, the activity in P. americana and M. spiraculartis was not lost at 90℃. These results show that the activity is different by insect species. On the immersion, all the five species of insects retained the catalase activity for long period (30 days) in 10% sugar solution, 15% ethanol, soy sauce and vegetable oil.

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The efficacy of toxic bait, which includes 0.005% flocoumafen, was tested against warfarin-resistant roof rats, Rattus rattus. Of 28 rats, 18 were killed after eating 8.3g/100g body weight of the bait in an average for 24 hours. Of the remaining 10 rats, nine were killed in 7.0 days with the bait of 9.9g in an average, which was supplied for 24 hours after a month of the 2nd supply. The fact suggests that flocoumafen has residual effect even after a month of inital supply. It is clear that flocoumafen is effective against warfarin-resistant roof rats but insufficient to kill all the rats with single supply.

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Eight to twenty-four sticky traps were placed for 6 to 8 days in each of 16 restaurants for measuring German cockroach populations. Mean population indices (catches/trap/day) ranged from 1.7 to 13.3 among the restaurants when total traps were included in the index calculation. When traps with individual indices less than 1 were excluded, the mean indices increased and ranged from 3.3 to 14.8. As the trapping method is not aimed to give absolute population estimates but to give relative estimates, it is desirable to exclude traps (or trap locations) with individual indices lower than a threshold level for controlling cockroaches. This procedure gives severe and clear mean indices in pre-treatment population surveys.

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[in Japanese]

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