Evaluation of native for biocontrol in Canadian tomato crops Paige Desloges Baril, Lauren Des Marteaux, Rose Labbé , Julia Mlynarek & Sherah VanLaerhoven

1 BACKGROUND 2 OBJECTIVES 4 IMPACT TO INDUSTRY The commercialization of more native for use in • The greenhouse sector is the fastest growing sector of Canadian • Assess the biocontrol potential of the candidate predators Dicyphus spp. greenhouse and field biocontrol will have multiple benefits for the horticulture1. Total greenhouse fruit and vegetable sales were over • Conduct laboratory trials on the Dicyphus spp. to determine: 2 industry. These benefits include: $1.587billion in 2019 , and Canada’s farm gate value for field vegetable 1. Reproductive rate production is estimated at over $1billion. 2. Development time and survival on various diets • Environmentally friendly alternatives to chemical pesticides. • Ontario leads both greenhouse and field fruit and vegetable production. 3. Daily maximum consumption of pests, e.g. Ephestia kuehniella (pyralid moth) eggs and whitefly nymphs • Tomato holds the largest commodity share of all produced vegetables • Better ecological safety compared to non-native species. in Canada for both greenhouse and field sectors (Fig. 1). • Assess whether the Dicyphus spp. can control whitefly on tomatoes in the field. • Diversifying the repertoir of native biocontrols for use for Greenhouse Field multiple crops and needs. Lettuce a) b) Tomatoes 10% Tomatoes METHODS Peppers 20% 3 Other (25 21% 42% FUTURE DIRECTIONS other crops) 44% Laboratory Trials Field Trial8 5 16% Carrots 1. Reproductive rate6 1 35% 10% Further research is still required to develop these biocontrol 10% Dry onions Tomato plants will be agents for commercial use. Some future directions include: Cucumbers Sweet corn transplanted into the • Improving rearing protocols for Dicyphus spp. to enable mass Fig. 1. Proportion of vegetables produced in Canadian greenhouses (a) and fields (b). field and covered by production for release. a mesh bag. Mating pairs Unlimited food Assess lifespan & egg production • Conducting more field trials to assess the biocontrol agents’ • Despite great success in these sectors, environmentally-friendly pest Mating pairs of Dicyphus spp. will be reared on E. efficacy in controlling other tomato pests. management remains a challenge: 2 kuehniella eggs ad libitum. Dicyphus spp. mortality and Whiteflies (10 mating • Assessing whether the Dicyphus spp. (which are omnivores) eggs laid will be assessed twice per week to determine • Chemical pesticides are often used to manage pests due to low cost, pairs) will be added to can cause crop damage. efficacy, and short lag time4. However, with increasing pesticide lifespan and reproductive rate. each bag and allowed 5 to establish for 1 week. • Assessing Dicyphus spp. persistence on other crops. resistance and consumers’ increasing desire for pesticide-free foods, an 2. Developmental time and survival on various diets 8: alternative is needed. 3 Tomato plants will be • While tomato crop pests such as aphids, leaf miners, and whitefly have divided into three many natural enemies, few native (Ontario-endemic) enemies have been treatments: no developed for commercial use in greenhouses and field crops to control predators (control),two 6 ACKNOWLEDGEMENTS these pests. Use of non-native biocontrol species can be ecologically mating pairs of D. damaging if they escape and pray on native species. Control discrepans (treatment We’d like to thank Catalina Fernandez (AAFC) for rearing the Dicyphus spp. 1), and two mating Thank you also to both the Labbé and Vanlaerhoven lab members for your Ephestia Brine shrimp E. kuehniella E. kuehniella pairs of D. famelicus • The use of native biocontrol insects (e.g. predators and parasitoids) kuehniella eggs support. Lastly, thank you to the University of Windsor. + pollen + Brine (treatment 2). would significantly reduce both the reliance on chemical pesticides and shrimp eggs Single Dicyphus nymphs will be added to a Petri dish This project is generously funded through the Canadian Agri-Science ecological risks associated with non-native biocontrol insects. Cluster for Horticulture 3, in cooperation with Agriculture and Agri- with one of four diets (above). These diets are often D. discrepans standard predator diets used for rearing. Survival and Treatment 1 Food Canada’s AgriScience Program, a Canadian Agricultural Partnership initiative, the Canadian Horticultural Council, time to moult will be recorded until adulthood. VanLaerhoven Lab • To develop native biocontrol insects for tomato crops, I first and industry contributors. 7 Homepage surveyed the Greater Sudbury region for predacious true bugs. 3. Feeding trials : Two species: Dicyphus famelicus and D. discrepans (Hemiptera: ) were abundant and How many prey D. famelicus WORKS CITED eggs remain? Treatment 2 7 amenable to laboratory rearing. Starved adult 4 1. Agriculture and Agri-Food Canada, Crops and Horticulture Division. (2018). Statistical Overview of the Canadian 24Hrs Greenhouse Vegetable Industry. Retrieved from the Government of Canada website. (Accessed 18 January 2021) Dicyphus famelicus Dicyphus discrepans 2. Crops and Horticulture Division, Agriculture and Agri-Food Canada, 2019. Statistical Overview of The Canadian Greenhouse Vegetable Industry. 3. Statistics Canada. Table 32-10-0365-01 Area, production and farm gate value of marketed vegetables 4. Summerfield, A., Grygorczyk, A., Buitenhuis, R., Poleatewich, A., & Brownbridge, M. (2019, December 10). Now Putting The Bios In Charge. Retrieved January 25, 2021, from https://www.greenhousecanada.com/now-putting-the-bios-in- charge-30555/ 5. Hawkins, N. J., Bass, C., Dixon, A., & Neve, P. (2019). The evolutionary origins of pesticide resistance. Biological Reviews, 94(1), 135-155. 24Hr starved Dicyphus spp. adults will be added to cups Claude Pilon 2006 Claude Pilon 2006 6. Sanchez, J. A., Gillespie, D. R., & McGregor, R. R. (2004). Plant preference in relation to life history traits in the with a fixed number of E. kuehniella eggs. After 24Hrs in Whitefly nymphs will be counted on three zoophytophagous predator . Entomologia Experimentalis et Applicata, 112(1), 7-19 Sudbury upper, middle, and lower tomato leaves each 7. McGregor, R. R., Gillespie, D. R., Quiring, D. M., & Foisy, M. R. (1999). Potential use of Dicyphus hesperus Knight Potential biocontrol insects for Ontario tomato pests. the cup, adults will be removed, and remaining eggs will (Heteroptera: Miridae) for biological control of pests of greenhouse tomatoes. Biological Control, 16(1), 104-110. be counted to assess prey consumption. week for 7 weeks to determine Dicyphus spp. 8. Labbé, R. M., Gagnier, D., Kostic, A., & Shipp, L. (2018). The function of supplemental foods for improved crop ability to suppress whitefly. establishment of generalist predators Orius insidiosus and Dicyphus hesperus. Scientific reports, 8(1), 1-12.