Marchioro C A, Krechemer F S, Foerster L A
Univ Federal de Santa Catarina, Curitibanos, Santa Catarina, Brasil,
Neotrop Entomol. 2015 Jun;44(3):270-7. doi: 10.1007/s13744-014-0263-4. Epub 2015 Feb 4.
Trichogramma pretiosum Riley and Trichogramma atopovirilia Oatman & Platner are natural enemies of Plutella xylostella (L.) in Southern Brazil. Laboratory studies to evaluate parasitoids performance under different conditions, such as temperature regimes, are necessary to assess their potential as biocontrol agents of P. xylostella. In most studies involving Trichogramma, parasitism rate is the main parameter used to evaluate parasitoid performance, ignoring that parasitoids can cause egg mortality by feeding on the host content and/or to multiple drilling without laying eggs. This study was conducted to investigate three main issues: how temperature affects T. pretiosum and T.atopovirilia development on eggs of P. xylostella, whether or not these species respond differently to temperature, and how important is the mortality they cause besides parasitism on P. xylostella. Temperature effects (from 10 to 30°C) on development, survival, parasitism rate, mortality, and total mortality caused by T. pretiosum and T. atopovirilia on eggs of P. xylostella were evaluated. Temperature affected the development time, female longevity, parasitism rate, mortality not directly related to parasitoid larval development, and total mortality caused on the host. No significant differences were recorded for the estimated thermal requirements for T. pretiosum and T. atopovirilia. However, the higher mortality caused by T. pretiosum indicates that this parasitoid is the most suitable to be used against P. xylostella. Also, the results suggest that the use of parasitism rate as the only parameter to evaluate the performance of T. pretiosum and T. atopovirilia may underestimate the potential of these parasitoids in regulating pest populations.
拟澳洲赤眼蜂（Trichogramma pretiosum Riley）和顶蛾赤眼蜂（Trichogramma atopovirilia Oatman & Platner）是巴西南部小菜蛾（Plutella xylostella (L.)）的天敌。开展实验室研究以评估寄生蜂在不同条件（如温度 regime）下的表现，对于评估其作为小菜蛾生物防治剂的潜力而言是必要的。在大多数涉及赤眼蜂的研究中，寄生率是用于评估寄生蜂表现的主要参数，却忽略了寄生蜂可通过取食寄主内容物和/或多次钻孔但不产卵而导致卵死亡。本研究旨在调查三个主要问题：温度如何影响拟澳洲赤眼蜂和顶蛾赤眼蜂在小菜蛾卵上的发育，这些物种对温度的反应是否不同，以及它们除寄生作用外对小菜蛾造成的死亡率有多重要。评估了温度（从10至30°C）对拟澳洲赤眼蜂和顶蛾赤眼蜂在小菜蛾卵上的发育、存活、寄生率、死亡率以及总死亡率的影响。温度影响发育时间、雌蜂寿命、寄生率、与寄生蜂幼虫发育无直接关系的死亡率以及对寄主造成的总死亡率。拟澳洲赤眼蜂和顶蛾赤眼蜂的估计热需求未记录到显著差异。然而，拟澳洲赤眼蜂造成的较高死亡率表明该寄生蜂最适合用于防治小菜蛾。此外，结果表明将寄生率作为评估拟澳洲赤眼蜂和顶蛾赤眼蜂表现的唯一参数可能会低估这些寄生蜂在调节害虫种群方面的潜力。
