Green ants (Oecophylla smaragdina) are a big feature of life in North Queensland. A lot of people dislike them for the very good reason that they sting but I don’t mind that too much because they are, after all, only defending themselves and they are fascinating to observe. I particularly admire the way they co-operate to make their nests.
They are among the many species of ant which have an amicable relationship with mealybugs. I don’t like mealybugs (Hemiptera, Pseudococcidae) as much as I like the ants, to be honest. Yes, I know mealybugs are only doing their best to survive, just like every other living creature, but they don’t do anything interesting and they do damage the plants they live on.
Yates Problem-solver gives the gardener’s perspective on them:
Mealybugs are small insects covered with a white mealy coating; some have white hairs attached to their bodies. The bugs feed by sucking on the plant juices. Mealybugs excrete a sticky substance called honey dew which ants like to feed on. The honeydew also provides a perfect medium for sooty mould growth. Mild temperatures and high humidity are perfect conditions for mealybugs to breed as eggs hatch every 2-3 weeks. Prolonged hot weather reduces numbers. Heavy infestations can occur on citrus trees, daphne, and other ornamental plants. Orchids and ferns, especially in shadehouses, can also become infested.