Abstract

The Indian meal moth, Plodia interpunctella (Hübner), is an economically important pest that infests various food commodities. There have been anecdotal reports of infestation by P. interpunctella of US soybeans shipped overseas in containers. However, limited information is available on the development ofP. interpunctella on soybean substrates. Two experiments were conducted to examine the development of P. interpunctella on whole soybeans, ground soybeans, and soybean meal, in comparison to a standard laboratory diet. The results from the first experiment showed that the laboratory diet was optimal for survival and development of P. interpunctella, while survival and development on whole soybeans was less optimal. The developmental time of P. interpunctella among the food substrates from first instars to adult emergence was completed within 25 to 40 days. In the first test with different food substrates, the number of larvae, pupae, and adults was highest on laboratory diet followed by soybean meal, and ground soybean, while no adult emergence was observed on whole soybeans. In the second experiment, infesting whole soybeans or laboratory diet with 100 P. interpunctella eggs showed that there was 7.3% adult emergence on whole soybeans compared to 25.8% adult emergence on laboratory diet. These experiments confirmed that soybean substrates are a suitable host for P. interpunctella infestation. The findings raise concerns regarding the potential risk of infestation of whole soybeans by P. interpunctella, which can lead to quality deterioration and economic impacts to the US soybean exports.