There is a variety of commercial suppliers to choose from when purchasing predatory insects and parasitoids for biological control. Some of them rear the insects themselves and others are distributors for some of the larger rearing facilities in Europe and Canada. There are some key things to consider when choosing a supplier. The first of which may be shipping dates and ordering deadlines. Depending on the predators being purchased, they typically ship one day a week (multiple for organisms such as predatory mites) and therefore there are strict ordering deadlines the week prior.
In general biological control needs to be implemented when pests are first detected, and at low levels, through active scouting efforts. If pests are already at damaging or outbreak levels alternative interventions (insecticidal soap or chemical application) to knock back the populations may be necessary prior to releasing predators for long-term control. Either way, it is important to contact multiple suppliers and record their ordering/shipping deadlines at the beginning of each season.
Cost in another important consideration. This varies depending on life stage and quantity of the agent being purchased. For some, such as green lacewings, there is not a lot of variation between suppliers, but for others you may see large variation. This may reflect the quality or origin of the agent (which rearing facility it is originating from). Explore the options to find the best fit for you and your farm.
Customer service is the last thing that I would urge you to consider. Some suppliers have done their own research with the agents they sell and can offer advice based on their own experiences. I have enjoyed working with companies that follow up on orders that I have placed or those that are prompt at answering the phone, returning emails and providing tracking information for shipments. Almost all of them supply their own recommendations for release rates, and depending on pest densities and acceptable damage levels, this is something that is not well established for high tunnel production.
Below is a list of suppliers that I have worked with. For a more extensive list please see this publication prepared by Jen White and Doug Johnson at the University of Kentucky:
https://entomology.ca.uky.edu/ef125
Arbico, Inc; PO Box 8910, Tucson, AZ 85738; (800) 827-2847; www.arbico.com
Beneficial Insectary, Inc.; 9664 Tanqueray Ct., Redding, CA 96003; (800) 477-3715; www.insectary.com
Evergreen Growers Supply; 15822 SE 114th Ave, Clackamas, OR 97015; (503) 908-1946
International Greenhouse Company; 70 Eastgate Dr., Danville, IL 61832; (217) 443-0600; www.greenhousemegastore.com
IPM Laboratories, Inc.; Locke, New York; (315) 497-2063; www.ipmlabs.com
Koppert Biological Systems, Inc.; 28465 Beverly Rd., Romulus, MI 48174; (734) 641-3763; www.koppertonline.com
Planet Natural; 1612 Gold Ave., Bozeman, MT 59715; (800) 289-6656; www.planetnatural.com
Plant Products Co. Ltd.; 314 Orenda Rd., Brampton, Ontario L6T 1G1 Canada; (905) 793-7000; www.plantprod.com
Rincon-Vitova Insectaries, Inc.; PO Box 1555, Ventura, CA 93002-1555; (800) 248-2847; www.rinconvitova.com