Biological warfare

July 3rd, 2005

oorlogsvoering.jpgBesides all the nice events in our greenhouse, we also have sometime events that are not that nice. Last month we got mealy bug in our greenhouse, especially at the heleconia’s and strelitzia. But with all the frogs in our greenhouse you cannot use a kind of plant pesticide. We first tried to remove the mealy bug by ourselves, but they reproduce quite fast. So we ordered at a garden centre the cryptolaemus montrouzieri beetle, also called the mealybugdestroyer, the natural enemy of the mealy bug. Within a week we received by mail 8 ladybeetles, 3-4 mm large. We had expected more beetles, as the order was for 50 m². But apparently these beetles reproduce rapidly. As soon as we put them at the plant they started to guzzle the mealy bug. Unfortunately a natural enemy of this beetle, a normal house spider, killed all the beetles within a couple of days. They easily got caught in their webs, webs we hardly noticed before. This successful biological warfare was not the warfare we had hoped for. So we finally took the heleconia’s and strelitzia out of our greenhouse, it is now a little bare in the greenhouse, as one of the heleconia’s almost reached to the ceiling and had a diameter of almost 2 meter. We had to prune both heleconia’s for the most part, they had over 20 flowers, and especially the flowers were completely covered by the mealy bug.The strelitzia has thick leafs, which we scrubbed several times. It looks like it helped. We leave them still a couple of weeks outside, to see if the mealy bugs really are gone.