Biology and management of Coleophora deauratella (Lepidoptera: Coleophoridae) in red clover seed-growing regions in North America and New Zealand

Abstract

Abstract Red clover (Trifolium pratense L.), a perennial forage legume belonging to the Fabaceae family, is grown for seed in many temperate regions of the world. Coleophora deauratella Leinig and Zeller (Lepidoptera: Coleophoridae) is a significant insect pest occurring globally in several primary red clover seed-producing regions. Coleophora deauratella inflicts crop damage by larval feeding on developing seed within individual florets, thus reducing seed yield. The first detection of C. deauratella and seed yield losses up to 90% were reported in the Peace River region of Alberta, in western Canada, in 2006, signifying its damage and potential threat to other red clover seed-producing areas of the world as an invasive insect pest species. As a result, crop stand age was reduced to 1 yr to mitigate seed yield loss caused by this pest in second-year fields in Alberta. Coleophora deauratella was first discovered in western Oregon in 2011, but the resulting economic damage remains unknown after more than a decade of its discovery. The first confirmed case of C. deauratella and tremendous seed yield devastation in red clover seed crops in the mid-Cantebury region of New Zealand occurred in 2016. Continued monitoring efforts in Oregon and New Zealand revealed that pest populations started receding after 2018, and the presence of unknown biocontrol agents, climatic, or genetic factors was speculated for its lower establishment rate. In this article, we discuss C. deauratella biology, ecology, and pest status in North America and New Zealand, along with the key research highlights to control C. deauratella.