草间小黑蛛对菜蚜和温室白粉虱捕食功能的比较

室内研究了草间小黑蛛(Erigonidium graminicolum)雌成蛛对菜蚜(Lipaphis erysimi)和温室白粉虱(Trialeurodes vaporariorum)的捕食功能,结果表明,草间小黑蛛对菜蚜成蚜、若蚜及温室白粉虱1龄至2龄初若虫的捕食功能反应属于HollingⅡ型。瞬间攻击力(a)分别为0.689 2、0.538 6、0.512 6,日最大捕食量(1/Th)分别为33.23、9.57、9.35头。草间小黑蛛有较强的种内干扰反应,随着捕食者密度的增大,捕食作用率相应降低;对菜蚜成蚜的捕食作用率(E)与自身密度(P)的函数关系式为E=0.202 6P-0.343 0。相互干扰可降低草间小黑蛛对菜蚜的寻找效应,但对其捕食量影响不大。菜蚜和温室白粉虱若虫的混合种群中草间小黑蛛偏嗜菜蚜。

Predacious Function Research on Erigonidium graminicolum to Lipaphis erysimi and Trialeurodes vaporariorum

The predacious function of Erigonidium graminicolum to Lipaphis erysimi and Trialeurodes vaporariorum was studied in the laboratory.The results showed that all the functional responses for E.graminicolum to the larvae of L.erysimi and the 1st~2nd instars larvae of T.vaporariorum could be described by the Holling modelⅡ.The moment attack(a) were 0.689 2,0.538 6,0.512 6 and the largest preying amount per day(1/Th) were 33.23,9.57,9.35,respectively.Inter-specific interference of spider was found in the experiment.The predation rate of E.graminicolum decreased along with the increase of predator density.The relationship between predation ratio(E) and the spider density(P) was described by equation E=0.202 6P-0.343 0.Mutual interference in the spiders could reduce the searching efficiency of E.graminicolum,however,had little affection on preying amount.When given the mixed populations of the larvae of L.erysimi and the 1st~2nd instars larvae of T.vaporariorum,the spiders were observed to prefer the former.