This year we are devoted to using all biological controls for our pest management in the greenhouses. We recently had a visit from our bug dealer, Ron Valentin from Biobest Canada to check our progress. Two weeks ago we applied our first shipment of beneficials and Ron was kind enough to schedule a visit as we all learn what to do.

It is important to know what the main pest problems are at various times of year and then in advance of that invasion “seed” in the proper predators or  beneficial insects. This time of year as the days lengthen it sends a signal to aphid populations to explode in the greenhouse so we bring in parasitic wasps called Aphidius (2 species). These guys are rather diabolical, they lay their eggs inside the aphid (erk), 2-300 eggs per aphid and then as the eggs pupate the aphid turns into a dried out husk of itself. The wasps hatch and the cycle continues. These little guys really take care of business.


The Aphidius wasps are small, about the size of the aphids, but narrow and actively flying about looking for prey. This photo shows both aphidius and cereal aphids on a blade of barley grass on a banker plant. This is a fun beneficial to start with because they are easy to see and the results are easy to see.

The idea with this banker plant is that cereal aphids are raised, “Cereal aphids only reproduce on monocotyledonous plants. Cereal aphids serve as a food source for the parasitic wasp Aphidius colemani, which reproduces on the cereal aphids.” This banker plant becomes a nursery to reproduce more of the parasitic wasps which keeps the population of the beneficial at hand at all time.

Stay tuned as we explore a new, earth friendly method for controlling greenhouse pests.