Wednesday, July 11, 2012
Milkweed bug sociology
The large milkweed bugs are in full flame in the garden, congregating mostly on the milkweed of course. The top picture is a dense aggregation of nymphs on a dried milkweed seed pod. You can see some shed exoskeletons there near them. These bugs commonly clump together like this, often in mixed age groups but sometimes more like-aged as these are. The eggs are laid on or in the green milkweed pods; since a female may lay 1000s of eggs it really is no surprise to find huge bunches of these bugs during their seasons.
Here you can see the milkweed seeds among the bugs.
Sometimes the milkweed bugs spread out and explore other plants. The nymphs supposedly feed only on milkweed seeds; their motivation to wander is therefore unexplained to me so far. Adults may feed on nectar or plant juices and of course wandering might be related to mating activity. Here is a nicely posed small group with an adult, a freshly molted adult and a couple of sub-adults along with a shed exoskeleton.
And sometimes a milkweed bug just wanders off by itself. This one was found on the buckwheat (eriogonum giganteum).
As for the species name Oncopeltus fasciatus, the Latin translates to something like "banded little shield" and should by no means be confused with neither necrotising fasciitis nor Mr. Cardui's current affliction Plantar fasciitis. While the PF has adversely affected the Mister's sociology including his ability to wander or even hobble sometimes, he still gamely sallies forth into the weekend yard sale scene with me. We're just a pair of large rummage bugs, perhaps.