自然条件下昆虫染螨类群的初步调查

通过对我国13个省(区、市)自然条件下昆虫染螨情况的野外调查,结果表明,染螨昆虫有13目、50科。并报道了部分昆虫染螨率、染螨部位及其主要螨类类群(蜱螨亚纲3目、16科),还讨论了寄生螨对寄主及其体位的选择偏好性等现象。

川西南地区小型兽类体外寄生革螨调查报告

198 7年 7～ 10月和 1988年 4～ 11月在川西南地区共采集到鼠类体外革螨 37种 ,190 9只。本文记录了这些革螨的宿主动物、采集地以及各宿主动物的染螨率。主要鼠种如社鼠、大耳姬鼠、黑腹绒鼠、高山姬鼠和松田鼠的染螨率分别为 49 32 %、2 3 92 %、7 45 %、7 37%和 4 17%

Dechlorination of DDT and DDE by Dithionite in Dicofol Type DDTs-Contaminated Soil

Dicofol type DDTs-contamination is of great concern as environmental organochlorine pollutant. In the present study, dechlorination time-course ofp,p＇-DDT and p,p＇-DDE in dithionite treated waterlogged DDTs-contaminated soil, non-contaminated soil solution and citrate-bicarbonate buffer （0, 50, 100 mmol L^-1, dithionite） for 72 hrs was investigated based on residual amount of p,p＇-DDTs （p,p＇-DDT and p,p＇-DDE） analyzed by GC-ECD. The metabolites ofp,p＇-DDTs in dithionite treated non-contaminated soil solution, and citrate-bicarbonate buffer were detected by GC-MSD. The dechlorination time-course of p,p＇-DDT and p,p＇-DDE exhibited rapid dechlorination at the first 3.0 hrs, slow dechlorination after 3.0 hrs. For 50 mmol L^-1 dithionite treatments, the dechlorination ratios ofp,p＇-DDT and p,p＇-DDE were 36.42% and 35.08% respectively at 3.0 hrs. For 100 mmol L^-1 dithionite treatments, the dechlorination ratios of p,p＇-DDT and p,p＇-DDE were 58.62% and 57.39% respectively at 3.0 hrs in DDTs-contaminated soils. Significant differences of dechlorination ratio were also confirmed in dependence on dithionite concentrations, reaction systems and the chemical structure of DDTs. The dechlorination ratio ofp,p＇-DDT/DDE increased with the increasing of dithionite concentrations irrespective of reaction systems. Dithionite-induced dechlorination ratio of p,p＇-DDT was higher than that of p,p＇-DDE. The p,p＇-DDD （1,1-dichloro-2,2-bis（4-chlorophenyl）-ethane）, p,p＇-DDE and p,p＇-DDMU （1-chloro-2,2-bis（4-chloropheny）-ethylene） were identified to be metabolites ofp,p＇-DDT in buffer and non-contaminated soil solution, however, no metabolites ofp,p＇-DDE treated by dithionite were detected. The possible pathways explaining the dechlorination of p,p＇-DDT and p,p＇-DDE by dithionite were also proposed. Dithionite could be used to develop an effective and fast remediation option for DDTs-contaminated soils and sediments.

佛山口岸地区鼠类调查

〔目的〕 掌握佛山口岸近年鼠类变化情况 ,为指导口岸灭鼠工作提供科学依据。〔方法〕 采用笼捕法 ,对佛山口岸鼠类的种群构成、生境分布、季节消长和携带病媒昆虫的情况进行了调查。〔结果〕 共捕获鼠形动物 5 0 5只 ,隶属 2目 (啮齿目、食虫目 ) ,2科 (鼠科、等 ) ,6种 (褐家鼠、黄胸鼠、小家鼠、板齿鼠、黄毛鼠、臭 ) ,以臭为各生境优势种 ,占鼠类种群构成的 6 1.98% ,其次为褐家鼠占 19.6 0 %。年平均鼠密度 3.88% ,全年鼠密度高峰出现在 6月和 12月 ,分别为 5 .4 5 %和 6 .5 8%。鼠染革螨率为 2 5 .74 % ,染蚤率为 2 8.31% ;革螨指数 0 .2 6 ,蚤指数为 0 .2 8。〔结论〕 佛山口岸鼠密度高于 1%的无鼠害标准 ,要降低鼠密度除合理用药灭鼠外 ,还应加强口岸综合治理。