Ghosh Anupam, Chandra Goutam
Department of Zoology, Bankura Christian College, Bankura.
J Vector Borne Dis. 2011 Jun;48(2):72-7.
In integrated vector management programmes, major emphasis is given on the application of biocontrol agents. In the present study, the hemipteran water bug, Laccotrephes griseus (Hemiptera: Nepidae) was evaluated to establish its functional response against the immature Culex quinquefasciatus Say in the laboratory.
Adult water bugs (L. griseus) were collected from different ponds in Bankura, West Bengal, India. Predation rate was determined in semi-field conditions. Functional response, regression equation analysis and rate of predation were also determined in the presence of an alternative prey.
The long-term predation experiment (up to 30 days) revealed that L. griseus is a very good predator of mosquito larvae. The functional curve analysis of L. griseus exhibited a Type II functional response. Their handling times and coefficient of attack rates were 29.37 min and 2.17 respectively. Regression equations showed that consumption rate was directly proportional to prey and predator densities and inversely proportional to the search area. The selectivity index, niche width and food breadth were also determined.
The present study revealed that L. griseus can consume a good number of mosquito larvae in the laboratory conditions. The long-term bioassay also indicates their predatory response against mosquito larvae in the semi-field conditions. The result of selectivity index, niche width and food breadth were also highest for Cx. quinquefasciatus. In these respects, the water bugs L. griseus are indicative of their release in the aquatic habitat where Cx. quinquefasciatus is the most dominant mosquito species.
在综合病媒管理计划中，主要重点在于生物防治剂的应用。在本研究中，对半翅目水生蝽类昆虫——灰华螳蝎蝽（半翅目：负子蝽科）进行了评估，以确定其在实验室中对致倦库蚊未成熟个体的功能反应。
从印度西孟加拉邦班库拉的不同池塘收集成年水生蝽（灰华螳蝎蝽）。在半野外条件下测定捕食率。在有替代猎物存在的情况下，还测定了功能反应、回归方程分析和捕食率。
长期捕食实验（长达30天）表明，灰华螳蝎蝽是蚊幼虫的优良捕食者。灰华螳蝎蝽的功能曲线分析呈现出II型功能反应。它们的处理时间和攻击率系数分别为29.37分钟和2.17。回归方程表明，消耗率与猎物和捕食者密度成正比，与搜索区域成反比。还测定了选择性指数、生态位宽度和食物宽度。
本研究表明，在实验室条件下，灰华螳蝎蝽能够捕食大量蚊幼虫。长期生物测定也表明它们在半野外条件下对蚊幼虫的捕食反应。对于致倦库蚊，选择性指数、生态位宽度和食物宽度的结果也最高。在这些方面，水生蝽灰华螳蝎蝽表明它们可释放到致倦库蚊为最主要蚊种的水生栖息地。
