近几十年来,公会捕食(IGP)引起了特别的关注,从理论和实践的角度来看。本文讨论了两种赤眼蜂(卵寄生虫)之间的干扰竞争-一方面,外在相互作用(即,雌性T.achaeae和油菜之间的间接竞争),另一方面,两个物种的幼虫之间的内在相互作用。此外,由于双重机制,T.achaeae比十字花菜更好的竞争者-前者充当后者的兼性高寄生虫,专门考虑寄生关系以及通过寄主摄食呈现捕食活动,与未寄生的卵相比,它优先考虑先前被十字花菜寄生的卵。这两种机制都取决于猎物密度,这通过功能响应的变化(即,在不同猎物密度下攻击的猎物数量之间的关系)初始阶段,攻击目标数量双曲线增加,然后达到渐近线,反映捕食者的处理能力),在没有竞争的情况下(瞬时搜索率a'=9.996±4.973天-1,处理时间Th=0.018±0.001天),到类型I(即,寄生率随着宿主密度的增加而线性增加,直到达到最大寄生率,当存在干扰竞争时,瞬时搜索率为a\'=0.879±0.072天-1,处理时间为Th≈0)。这些结果表明,该物种具有更大的死亡潜力,T.achaeae,在与其他物种竞争的条件下,在这种情况下。基于此,讨论了它们对寄生虫生物防治害虫的影响。
Over recent decades, intraguild predation (IGP) has attracted special attention, both from the theoretical and practical standpoints. The present paper addresses the interference competition between two Trichogramma species (egg parasitoids)-on the one hand, the extrinsic interactions (i.e., the indirect competition between female T. achaeae and T. brassicae), and on the other, the intrinsic interactions between the larvae of both species. Furthermore, T. achaeae is a better competitor than T. brassicae due to a dual mechanism-the former acts as a facultative hyperparasitoid of the latter, exclusively considering parasitism relationships as well as presenting predation activity by host feeding, which gives preference to eggs previously parasitized by T. brassicae over non-parasitized eggs. Both mechanisms are dependent on the prey density, which is demonstrated by a change in the functional response (i.e., the relationship between the numbers of prey attacked at different prey densities) of T. achaeae adult female-it changes from type II (i.e., initial phase in which the number of attacked targets increases hyperbolically and then reaches an asymptote, reflecting the handling capacity of the predator), in the absence of competition (an instantaneous search rate of a\' = 9.996 ± 4.973 days-1 and a handling time of Th = 0.018 ± 0.001 days), to type I (i.e., linear increase in parasitism rate as host densities rise, until reaching a maximum parasitism rate, and an instantaneous search rate of a\' = 0.879 ± 0.072 days-1 and a handling time of Th ≈ 0) when interference competition is present. These results show that there is a greater mortality potential of this species, T. achaeae, in conditions of competition with other species, T. brassicae in this case. Based on this, their implications in relation to the biological control of pests by parasitoid species are discussed.