Garden Pests and Diseases: Pill bug/rolly polly/ doodle bug...enemy??, 0 by Night_Bloom

Night_Bloom wrote:
Ants can be a good and bad thing at the same time when it comes to insects and aphids. In some circumstances, fire ants are seen as a very beneficial thing for example - a good instance is in sugar cane fields where they drastically reduce the pest population feeding on the sugarcane. Ants, however, as konkreteblonde observed, are not very picky. They'll eat the good as well as the bad bugs.

As for ants and aphids, it may depend on the type of ants. I think fire ants, for example would be just as likely (if not more likely) to pick up the aphids for eating as they would to visit them for honeydew. Many other types of ants, however, will defend the aphids so that they can have the honeydew... Unless they get hungry or need protein more than sugar (which depends on whether they are raising larvae, the time of year, etc. etc.). As an example, here is a picture of my poor Chinese beans. I had a continuing battle with the ants and the aphids later in the year (when ants most want sugar). I would blast the aphids (and ants) off the beans with a hose, killing many of the aphids. I didn't want to kill the ants - they would go running away when I blasted, or otherwise would survive the water - because the ants also would attack both pest caterpillars and leaf beetles in my garden (I had seen them taking both as prey). Unfortunately, the ants would also carry the aphids back up and stick them back on the beans. I would come back a day or two later and there would be those %&^$* aphids again with the ants proudly guarding them, so I'd have to come back with the hose.

So the main answer is, if the lady beetles, lacewings, parasitic wasps, and syrphid fly larvae don't get your aphids - and they almost always get mine just when I think I'll have to take action - you can blast em with the hose. That ususally works fine as long as you don't have ants bringing them back up.

The ants here with the aphids are carpenter ants. In general, if you have larger sized ants they are usually either carpenter ants or they are a Formica species of some kind (which look an awful lot like carpenter ants).

Carpenter ants guarding their aphids on Chinese beans...