伞裙追寄蝇对黏虫幼虫的寄生功能反应

Functional response of Exorista civilis to Mythimna separatalarvae

室内条件下研究了伞裙追寄蝇（Exorista civilis Rondani）对黏虫[Mythimna separata （Walker）]幼虫的寄生功能反应.结果表明,伞裙追寄蝇功能反应曲线在15～35℃内为HollingⅡ型,随着寄主黏虫数量的增加,伞裙追寄蝇寄生量呈上升趋势,当寄主数量增加到一定数量时,其寄生量趋于稳定.23℃时拟合方程为Na =0.803 3 N/（1＋0.803 3×0.015 4N）,1头伞裙追寄蝇雌蝇寄生1头黏虫幼虫所需时间为0.803 3 h.伞裙追寄蝇的自身密度对寄生有干扰作用,可用Hassell-Varley模型E=0.553 3 P-1.5655表示,由此公式可以得出,伞裙追寄蝇的发现域与其自身密度成反比增加,寄生蝇相互之间的干扰效应降低了寄生效能.

The parasitic functional response of Exorista civilis Rondani to Mythimna separata （Walker） larvae was observed in the laboratory. The results showed that the functional response belonged to Holling type 11 in a certain temperature range（15- 35 ℃ ）. The number of parasitized larvae increased with the increase of the larvae density, but the searching efficiency decreased with the increase of E. civilis and M. separata density. At 23 ℃, the functional response could be expressed as Na =0. 803 3 N/（1＋0. 803 3×0. 015 4 N）. The time spent in one host parasitized by single E. civilis was 0. 803 3 h. The density of E. civilis affected the parasitism to some extent and the interference fitted Hassell-Varley model, which could be well simulated as E = 0.553 3 P^-1 565 5, indicating that the discovery domain of E. civilis decreased with increasing density of itself. The interference between parasites weakened the parasitic function.