Woolly Aphids

Tennessee Warbler

This autumn, a certain insect has been evident on some of the beech trees in the central Ohio area.  At first glance, it doesn’t look like an insect at all.

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These look like lots of tiny cotton balls on a tree branch.  But if you look closely, you can see some of them moving…

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These are Woolly Aphids:

The woolly aphid is a sucking insect that lives on plant fluids and produces a filamentous waxy white covering which resembles cotton or wool. The adults are winged and move to new locations where they lay egg masses. The larvae often form large cottony masses on twigs, for protection from predators. They come from Japan.

Woolly aphids feed by inserting their needle-like mouthparts into plant tissue to withdraw sap. They are able to feed on leaves, buds, bark, and even the roots of the plant. As a result of feeding on the sap, woolly aphids produce a sticky substance known as honeydew, which can lead to sooty mold on the plant.

Woolly aphids generally are not much cause for alarm, although they can cause rather unsightly damage to plants, which is particularly a problem for growers of ornamentals.

I’d never seen these insects before; apparently there are specialized types that feed on various other plant species- for example, Asian Hackberry.  But these particular aphids fed upon Beech Trees.

As interested as I was to see these tiny creatures, the migrating autumn warblers that I had also been watching were even more interested.  This was food for them, and migration is hungry work.

One September day, a certain Tennessee Warbler took a fancy to a particular branch full of these little fuzzballs that I was looking at.  Last week you may have seen another such bird taking a bath in a stream on this blog.  But this bird was famished.

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Watch as our bird finds a banquet…

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The bird started eating.

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Talk about an acrobat, eating upside down- but warblers are used to doing this while searching for bugs on leaves.

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Here’s another angle on our hungry friend.

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This bird did not mind me getting pretty getting close to it while it ate.  Yet even this hungry migrant didn’t make a dent in the aphid population.  Scientifically speaking, this is an example of what used to be called R-selection, which meant that aphids have a huge number of offspring that they spend very little effort on- most of them are eaten, but that doesn’t matter to the aphids because enough survive to reproduce and continue on.  Nature is often like that.

I was quite happy to be in the right place at the right time to photograph all of this.  Personally, it’s been a pretty good warbler autumn for me- though that time is now drawing to a close as the seasons flow on.