Seehausen M Lukas, Jones Ian M, Smith Sandy M, Bourchier Robert S
Faculty of Forestry, University of Toronto, 33 Willcocks Street, Toronto, Ontario M5S 3B3, Canada.
Insect Ecology and Biological Control, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, Alberta T1J 4B1, Canada.
Environ Entomol. 2025 Feb 19;54(1):39-45. doi: 10.1093/ee/nvae095.
Facultative diapause is a life history trait that allows insects to undergo continuous development when conditions are favorable or to enter diapause when they are not. Insect voltinism can have an impact on the success of a weed-biological control agent because additional generations can increase agent population growth and reduce late-season recovery in the target weed. The most common factors that cue diapause are photoperiod and temperature; however, the role of nutrition is increasingly being recognized. We conducted a laboratory experiment to examine the effects of photoperiod and foliage age on diapause induction, pupal weight, and pupal development time in Hypena opulenta (Christoph) (Lepidoptera: Erebidae), a biological control agent for invasive swallow-worts in North America. A factorial experimental design was employed whereby H. opulenta was reared at long (16:8 h light:dark) and short (12:12 h) photoperiods on young and old swallow-wort foliage (Vincetoxicum rossicum Kleopow) Barbar. (Apocynaceae). Photoperiod was the only factor that affected diapause induction in H. opulenta. While foliage age did not affect diapause induction, it did affect pupal weight and pupal development time, with older foliage resulting in lower pupal weight and extended pupal phase. In field conditions, these impacts could affect pupal mortality through reduced winter preparedness and increased exposure to predators. These results support H. opulenta voltinism models based on photoperiods and indicate that the tendency of captive-reared H. opulenta to enter diapause after 2 or 3 generations, even in the absence of short photoperiods, is not a result of changing foliage age.
兼性滞育是一种生活史特征，它使昆虫在条件适宜时能够持续发育，而在条件不适宜时进入滞育状态。昆虫的化性会对杂草生物防治剂的成功产生影响，因为额外的世代可以增加防治剂种群的增长，并减少目标杂草在生长季后期的恢复。引发滞育的最常见因素是光周期和温度；然而，营养的作用也越来越受到认可。我们进行了一项实验室实验，以研究光周期和叶片年龄对北美入侵性马利筋的生物防治剂——丰盛希夜蛾（Christoph）（鳞翅目：夜蛾科）滞育诱导、蛹重和蛹发育时间的影响。采用析因实验设计，将丰盛希夜蛾在长（16:8小时光照:黑暗）和短（12:12小时）光周期下，饲养在幼嫩和老龄马利筋叶片（萝藦科马利筋属Kleopow）上。光周期是影响丰盛希夜蛾滞育诱导的唯一因素。虽然叶片年龄不影响滞育诱导，但它确实影响蛹重和蛹发育时间，老龄叶片导致蛹重降低和蛹期延长。在田间条件下，这些影响可能通过降低越冬准备和增加被捕食风险来影响蛹的死亡率。这些结果支持基于光周期的丰盛希夜蛾化性模型，并表明即使在没有短光周期的情况下，圈养的丰盛希夜蛾在2或3代后进入滞育的倾向并非叶片年龄变化的结果。
