Wang Jie, Di Ning, Wang Cheng-Xing, Zhu Zheng-Yang, Prager Sean M, Huang He-Xi, Trumble John T, Desneux Nicolas, Li Yuan-Xi, Wang Su
Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.
College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Insect Sci. 2025 Jul 7. doi: 10.1111/1744-7917.70125.
The increased basic knowledge of biological control agents' bio-ecology under environmental stress provides useful information for optimizing integrated pest management. With an increasing awareness of cadmium (Cd) pollution in agroecosystems, this study evaluated the transgenerational effects and host preference of two widely distributed and utilized egg parasitoids, Trichogramma dendrolimi and Trichogramma japonicum through bottom-up effects mediated by Cd. The host rice moth Corcyra cephalonica was reared on a diet with 20 mg/kg Cd exposure for 1 generation; eggs were collected, and then exposed to Trichogramma. The survival rate, longevity, daily number of parasitized eggs, and fecundity of second generation (F1) females, emergence rate, and female adult proportion of the third generation (F2) were tested. After emerging from Cd-exposed hosts, the survival rate and longevity of F1 T. dendrolimi female adults were significantly increased, but the daily number of eggs parasitized by, and fecundity of, F1 T. japonicum were significantly decreased. Cd exposure significantly resulted in a preference for hosts exposed to Cd in both F1 T. dendrolimi and T. japonicum, whereas no such host preference was observed when the first generation (F0) parasitoids were not exposed to Cd during their development. Our study shows the transgenerational effects and host preference on natural enemies under heavy metal exposure stress in a species-specific way. This highlights the potential synergetic effects of heavy metal contamination on biological control. Specifically, the release of T. dendrolimi, rather than T. japonicum, should be favored at Cd-contaminated sites, where T. dendrolimi is a more suitable biocontrol agent.
对生物防治剂在环境胁迫下生物生态学基础知识的深入了解，为优化综合虫害管理提供了有用信息。随着对农业生态系统中镉（Cd）污染的认识不断提高，本研究通过Cd介导的自下而上效应，评估了两种广泛分布和利用的卵寄生蜂——松毛虫赤眼蜂和日本赤眼蜂的代际效应和寄主偏好。将寄主米蛾在含20 mg/kg Cd的饲料上饲养1代；收集卵，然后让其接触赤眼蜂。测试了第二代（F1）雌蜂的存活率、寿命、每日寄生卵数和繁殖力，以及第三代（F2）的羽化率和雌成虫比例。从接触Cd的寄主中羽化后，F1代松毛虫赤眼蜂雌成虫的存活率和寿命显著增加，但F1代日本赤眼蜂的每日寄生卵数和繁殖力显著下降。Cd暴露显著导致F1代松毛虫赤眼蜂和日本赤眼蜂对接触Cd的寄主产生偏好，而当第一代（F0）寄生蜂在发育过程中未接触Cd时，未观察到这种寄主偏好。我们的研究以物种特异性方式显示了重金属暴露胁迫下天敌的代际效应和寄主偏好。这突出了重金属污染对生物防治的潜在协同效应。具体而言，在Cd污染的地点，应优先释放松毛虫赤眼蜂，而不是日本赤眼蜂，因为松毛虫赤眼蜂是更合适的生物防治剂。
