著者
真喜屋 清 石黒 虎男 高橋 美和子 大橋 昭任 竹下 三喜男 彭城 郁子
出版者
産業医科大学学会
雑誌
産業医科大学雑誌 (ISSN:0387821X)
巻号頁・発行日
vol.8, no.1, pp.39-46, 1986-03-01

水田皮膚炎の原因となる烏類住血吸虫セルカリアの中間宿主ヒメモノアラガイについて, 乾燥した水田の稲株で越冬する集団, 初夏の水田で越冬貝がら発育した大型貝集団および産卵後に生じた新生貝集団の水田内における分布様式を明らがにすると同時に, 越冬集団の分布を左右する土壌水分量および土壌粒子の組成との関連について解明した. 越冬貝, 大型貝および新生貝の各集団とも水田内では均一に分布せず負の二項型に適合する集中性の不均一な分布をし, 集中度は新生貝>越冬貝>大型貝個体群の順に強かった. 分布様式と集中度から考えると, 翌春水が張られた後稲株から出た越冬貝集団がこの水田の中央部寄りで成熟, 産卵後に分散して行き, 水田周縁部に集まったものと考えられた. 秋の繁殖期に産出された稚貝は, 土壌水分のより多い場所を選び稲株の地下茎に潜入することによって, 乾燥した冬の水田で生きのびるものと考えられ, また,水分の多い場所の土壌はそうでない場所に比べて細砂の割合が高く, 粗砂の少ない組成をしていた.(1985年11月5日 受付)
著者
彭城 郁子 須藤 千春 伊藤 秀子
出版者
日本衛生動物学会
雑誌
衛生動物 (ISSN:04247086)
巻号頁・発行日
vol.41, no.3, pp.227-234, 1990
被引用文献数
3 4

Some factors that affect the occurrence and termination of quiescence in nymphs of Dermatophagoides farinae, were examined. The mites aggregating on the rims and covers of culture bottles were collected when the mite populations were increased. They were kept at 25℃, 75% relative humidity (RH), without food. After 1 month, about 20% of the mites passed into quiescent state, and a half of them remained quiescent for 5 months at 25℃, 75% RH, and further 5 months at room temperature. Most of the quiescent mites were protonymphs. They were glued to the substrate such as covering filter paper. Quiescence in half of the 8-week-aged nymphs terminated when they were disturbed by being separated from the substrate, pretreated at 5℃ for 1 week, and then incubated at 25℃, 75% RH. But the nymphs did not moult by pretreatment of 10,18,and 25℃ for 1 week. The nymphs in age of 20-week or more moulted even when they were continuously incubated at 25℃ and 75% RH, if separation from the substrate was made. The moulting rates depended on age in the nymphs; the older the nymphs, the faster the moulting. However, the nymphs glued onto the substrate remained quiescent. Moulting of nymphs with age of 22-week or more was suppressed by incubating them at lower temperatures than 25℃, or lower than 55% RH. The contact of the quiescent nymphs with water for 3hr enhanced moulting even when they were incubated at 33% RH. These results suggest that quiescence in nymphs of D. farinae observed in the present study might also involve a very similar phenomenon to diapause.