USDA Forest Service, Northern Research Station, Lansing, MI.
Department of Entomology, Michigan State University, East Lansing, MI.
Environ Entomol. 2021 Apr 23;50(2):280-292. doi: 10.1093/ee/nvaa169.
In North America, the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), continues to spread, and its egg parasitoid, Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae), is being released for emerald ash borer biocontrol well beyond their endemic climatic ranges in China. We developed a multiple cohort rate summation model to simulate O. agrili F0, F1, and F2 generations, and emerald ash borer oviposition for examining host-parasitoid synchrony across a north-south gradient from Duluth, MN (latitude 46.8369, longitude -92.1833) to Shreveport, LA (latitude 32.4469, longitude -93.8242). Temporal occurrences of critical day length for O. agrili diapause induction were integrated into the model. We used O. agrili and emerald ash borer trapping data from south central and northwestern Lower Michigan for model validation. Simulations demonstrated that 1) F0 adult emergence consistently occurred 2-5 d before emerald ash borer oviposition began; 2) F1 adult emergence was most synchronized with peak emerald ash borer oviposition compared with other generations; and 3) emerald ash borer oviposition was complete, or near so, when F2 adult emergence was predicted across the north-south gradient. Comparison of O. agrili trap captures with model simulations demonstrated that primarily two adult O. agrili generations (F0 and F1) emerged per year in Michigan and almost all F2 larvae entered diapause despite day lengths longer than critical day length in south central Michigan. Critical day length varied temporally across the north-south gradient during emergence of O. agrili generations. Determining day lengths perceived by O. agrili larvae in the field should improve model realism for examining spatiotemporal variation in O. agrili population dynamics.
在北美洲，灰象甲的卵寄生蜂，绿柄象甲啮小蜂（膜翅目：长尾小蜂科），继续传播，其卵寄生蜂在中国的地方气候范围之外被释放用于控制灰象甲。我们开发了一个多龄期速率总和模型来模拟 O. agrili F0、F1 和 F2 代以及灰象甲产卵，以检查从明尼苏达州德卢斯（纬度 46.8369，经度-92.1833）到路易斯安那州什里夫波特（纬度 32.4469，经度-93.8242）的南北梯度上的寄主-寄生蜂同步性。该模型整合了 O. agrili 滞育诱导的临界日长的时间发生。我们使用密歇根州中南部和西北部的 O. agrili 和灰象甲诱捕数据进行模型验证。模拟表明：1）F0 成虫的出现始终比灰象甲产卵开始提前 2-5 天；2）与其他世代相比，F1 成虫的出现与灰象甲产卵高峰最同步；3）在南北梯度上预测 F2 成虫出现时，灰象甲产卵已完成或接近完成。将 O. agrili 诱捕器的捕获与模型模拟进行比较表明，在密歇根州，每年主要有两代 O. agrili 成虫（F0 和 F1）出现，尽管在密歇根州中南部的日长长于临界日长，但几乎所有 F2 幼虫都进入了滞育。临界日长在 O. agrili 世代的南北梯度上随时间变化。确定 O. agrili 幼虫在野外感知的日长应该会提高模型的现实性，以检查 O. agrili 种群动态的时空变化。
