Friday, October 19, 2012

Bug of the Day

I've been watching these swarming all over some milkweed plants for a few days, and I've been meaning to take a photo, and figure out what they are.  I finally succumbed to the temptation today. To identify them I used the goggle search "milkweed bug", and found that they are, indeed, milkweed bugs, and that this one appears to be the Large Milkweed Bug, (Oncopeltus fasciatus).

This bug (and it is a "true" bug, a member of the hemipteran family), has an interesting life cycle for a bug:
Adults that survived winter mate in May-June, when common milkweed plants have grown enough to provide shelter. During mating, female and male may become connected for up to 10 hours. Eggs are laid on seed pods or under a leaf. Average female lays 30 pale orange eggs in a day, in several batches during summer. Eggs change color, becoming more intensely orange toward hatching. This insect undergoes incomplete metamorphosis. Nymphs hatch after about 1 week and molt 5 times before becoming adults.

Adults and nymphs feed on milkweed plant juices, seeds and occasionally on other plant juices. When their native plant is scarce, they may become scavengers and predators. Both nymphs and adults use milkweed as their primary source of food. After feeding on milkweed plant or seeds, the insects accumulate toxic glycosides in their bodies. This, combined with warning orange color, protects them against predators (aposematism).All milkweed bugs live up to 4 months.
In the picture you can find adults (with wings), nymphs, with wing stubs, and a couple of freshly molted adults (the two light orange individuals).

While I was out, I also caught another Eastern Comma butterfly, visiting a Persimmon rotting on the ground, showing how the mottled underside of their wings is excellent camouflage, and an itty bitty Pearl Crescent flitting around in the grass. 

Note the size by comparison with the grass and clover.

It can't be long now until the butterflies are gone for the winter.

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