Development of a multiplex polymerase chain reaction assay for the identification of common cutworm species (Lepidoptera: Noctuidae) infesting canola in western Canada

Cutworms (Lepidoptera: Noctuidae) constitute an important insect pest complex that causes damage to a variety of crops across western Canada and particularly in canola (Brassica napus Linnaeus; Brassicaceae) crops in recent years. However, individual cutworms are very difficult to identify to species based on morphology alone, particularly at the larval stage. Problems with pest identification can lead to difficulties in recommending appropriate management strategies for specific cutworm infestations. In the current study we have developed and applied a single-step multiplex polymerase chain reaction assay, based on the rRNA ITS2 genomic sequence, which can be used to identify, to the species level, individuals of the following five key cutworm species: Agrotis orthogonia Morrison, Euxoa auxiliaris (Grote), Euxoa ochrogaster (Guenee), Feltia jaculifera (Guenee), and Lacinipolia renigera (Stephens). This molecular identification tool will be a valuable asset in agronomic and ecological studies of cutworm infestations in the canola cropping system across western Canada and potentially could be used as a timely identification tool for determining pest infestations to the species level during outbreaks.