Aphid Farming

Click Images




What I thought was a fluffy white fungus on a tattered bush, turned out to be Wooly Aphids; the ants scurrying around them, well, they were practicing the insect kingdom’s version of agriculture.

I was enjoying the late afternoon sun at Loch Raven, and hoping that the pair of Bald Eagles soaring in the distance would come my way again.  I sat down on the hillside just above the water, and began examining the little patch of ground around me, and then, spotted a white fluffy substance on what appeared to be an Alder shrub. Its leaves were in tatters, obviously eaten away by hungry insects, but I made no connection to the condition of the leaves and this fluffy white stuff.

It captured my attention because the late afternoon sun was shining on it, and the lake was in the background. I knew if I took a close up shot with the dark blue water out-of-focus, the brightly lit fluff would make an interesting color contrast.

I set up my camera for some close in shots and gained focus on the white fluff; when I noticed some ants moving around the patch of white stuff, I instantly wanted one in the shot.  An ant crawled onto the sunlit portion of the branch, his color made even more of a contrast. His abdomen was translucent orange and his darker head stood out as I dialed my camera into focus.

I took a handful of shots, and a few of the chewed up leaves, then a full shot of the small bush to help identify it later. I still thought I had photographed just a curious white fungus, and a few ants.

I would later find out that I had photographed one of the insect kingdom’s most interesting behaviors, aphid farming. Numerous ant species are known for tending to herds of aphids, the ants want the sweet concentrated plant sap that the aphids pass as waste. Ant colonies have been documented standing guard for the aphids, protecting them from predatory insects, and even killing the larvae of insects that feed on aphids.

There are variations of this behavior, and sometimes the relationship can be rather complex. In certain ant and aphid species combinations, the ants even relocate the aphids to new bushes once the food source has been exhausted. There are even certain types of ant-aphid pairings where the ants milk the aphids to make them excrete their waste. Aphid poop is known in entomology circles as honeydew, and I can see why they came up with a clever name for it.

In the case of the wooly aphid, that fluffy white stuff is a protective waxy coating secreted to make them distasteful to insect eating animals. Instead of getting a mouthful of sweet juicy aphids, the animal gets a taste of the bitter waxy fluff.

That particular cluster of Wooly Aphids has to number in the thousands, and if you look around the edges, you can see smaller clusters of a just a few individuals.

I plan on visiting these ants and their aphid herd again in a few days.






Location and Weather Conditions

Location: Loch Raven Reservoir, Maryland

Date: October 8, 2014

Time: 4:25 PM

Temp: 69F

Weather Conditions: Sunny with light scattered clouds