Data from: Evolution of critical day length for diapause induction enables range expansion of Diorhabda carinulata, a biological control agent against tamarisk (Tamarix spp.)

In classical weed biological control, small collections of arthropods are made from one or a few sites in the native range of the target plant and are introduced to suppress the plant where it has become invasive, often across a wide geographic range. Ecological mismatches in the new range are likely, and success using the biocontrol agent may depend on post release evolution of beneficial life history traits. In this study we measure evolution of critical day length for diapause induction, (day length at which 50% of the population enters dormancy), in a beetle (Diorhabda carinulata) introduced into North America from China to control an exotic shrub, Tamarix spp. Beetle populations were sampled from four sites in North America seven years after introduction and critical day length was shown to have declined, forming a cline over a latitudinal gradient At one field site decreased critical day length was correlated with 16 additional days of reproductive activity, resulting in a closer match between beetle life history and the phenology of Tamarix. These findings indicate an enhanced efficacy and an increasingly wider range for D. carinulata in Tamarix control.

经典杂草生物防治领域中，研究人员通常从目标植物原产地的一个或少数几个采样位点采集少量节肢动物（arthropods），将其引入目标植物已形成入侵的、通常覆盖广泛地理范围的区域以抑制其种群扩张。新入侵区域内极易出现生态不匹配问题，而该生防天敌（biocontrol agent）的防治成功与否，可能取决于其在释放后有益生活史性状的演化。本研究针对一种从中国引入北美、用于防治外来灌木柽柳属（Tamarix spp.）的甲虫（Diorhabda carinulata），测定其滞育（diapause）诱导临界日长（即种群中50%个体进入休眠的日长）的演化情况。研究人员在该甲虫引入北美七年后，从北美四个采样位点采集甲虫种群，结果显示其滞育诱导临界日长已出现下降，并沿纬度梯度形成渐变群（cline）。在其中一个野外采样点，临界日长的缩短与繁殖活动延长16天显著相关，使得甲虫的生活史与柽柳的物候（phenology）匹配度大幅提升。上述研究结果表明，该甲虫在柽柳防治中的防控效能得到增强，其适用范围也愈发广泛。