Tuesday, July 24, 2007

Bugs Galore

We had lots of good experiences on the field trips during last weekend's Ohio Dragonfly Conference. And that's what really gets people interested in this stuff, or anything for that matter - good memories. Plenty of those were generated, thanks to a lot of very knowledgeable leaders, and weather that was totally flawless for bug-seeking. And please, if you're one of those hard-case entomologists who bristles at the colloquialism "bug", spare me. I know they're really "insects".

It don't get no better than this, if you're a dragon-seeker. Several of us were on our bellies photographing a very cooperative Orange Bluet, Enallgma signatum, when this Violet Dancer, Argia fumipennis subsp. violacea, decided to use Marlo Perdica's hand as a perch. Of course, the rest of us demanded that she freeze, so we could document the moment. The Violet Dancer was a beaut, too - nice purple male - but a bit hard for Marlo herself to photograph...

While out on a pre-scouting trip, we came across a very interesting butterfly. Fitting it is the only carnivorous butterfly in North America, as we were focused mostly on dragonflies, and bugs don't get any more carnivorous than the Odonata. Anyway, veteran field naturalist extraordinaire Jim Davidson spotted a Harvester, Feniseca tarquinius, which proved to be quite cooperative.

A quarter-sized beauty, the habits of the Harvester are bizarre by butterfly standards. The larvae eat at least four genera of woolly aphids, which often form conspicuous clusters on host trees. Around here, American beech, Fagus grandifolia, and any of several species of alder, Alnus sp., are good host plants for suitable aphids. Some authorities believe that Harvesters are probably a lot more common than thought, but their populations tend to be highly localized and the tiny adults can be easily missed as they don't come to flowers for nectar.

A swarm of woolly aphids on a beech tree. You've probably seen these before; the colonies are bizarre-looking and conspicuous. And where you want to seek the odd, light brown Harvester caterpillars, their long setae (hairs) often gunked up with whitish secretions from the aphids. The caterpillars live right amongst the aphids, casually munching them as the mood strikes. The adult butterflies often hang close to the aphids, too, as they shun plant nectar for the apparently tastier "honeydew" secreted by the aphids.

Nature can be strange sometimes.


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