Developing new and native hemipteran biocontrol agents for the Canadian greenhouse industry

Abstract: Given today’s stringent global regulatory environment, the importation of non-native biocontrol agents into new areas is increasingly restricted, owing primarily to concerns of nontarget effects by introduced species. This development highlights the importance of looking within one’s own back yard to identify indigenous natural enemies which could be used as biocontrol agents for a diversity of greenhouse and field crop pests. Between 2018 and 2020, we conducted surveys across Ontario to identify several predatory hemipteran species that can be easily maintained in lab cultures, adapt well to greenhouse crops, and demonstrate good control potential for a diversity of arthropod pests. Through these surveys, we were able to successfully identify and establish colonies for three predatory nabids (Nabis americoferus, N. roseipennis and Hoplistocelis pallescens) and three predatory mirids (Dicyphus famelicus, D. discrepans, and Macrolophus tenuicornis). To date, we have characterised the life histories and the basic predatory capacities for most of these species and confirmed that each can successfully establish on tomato and mullein (Verbascum thapsus) as a banker plant. We present an overview of some of these key findings, along with a summary of preliminary greenhouse trials aimed at characterising pest prey feeding capacity, crop establishment potential, and the value of supplemental foods for supporting these predators in greenhouses. Overall, our results have allowed us to formulate basic best practices for application of some of these hemipteran species. Importantly, this work represents the foundation for the commercial development of new and native biocontrol agents for the North American greenhouse industry.