Both the ladybirds and their larvae feed on aphids. Introducing them into your greenhouse is a good way to fight aphids. As long as there are aphids to feed the ladybirds, they will stay in the greenhouse. "Our" ladybirds have reproduced several since their introduction into the greenhouse two months ago.
Considering the fact that these pretty bugs are actually predators, one could wonder why in Holland they are used as a symbol against what we call "senseless violence". It is even more questionable after reading this article from BBC Earth.
Another natural enemy of aphids is the ichneumon wasp. As our plant life has been exploding this spring, we have been finding more and more of this wasp species in the greenhouse. A very welcome development for our aquaponics crew, as these parasitic wasps are also a natural enemy of ants.
