Tuesday, June 14, 2011
Oncopeltus fasciatus metamorphosis
I figured the group of large milkweed bugs must be getting ready to molt into adulthood so I checked on them from time to time. On the afternoon of June 4 I noticed a shed exoskeleton near the group and knew the final stage of their metamorphosis was underway.
Nearby was a bug standing off by itself under a leaf; it's exoskeleton was loose, looking a bit like skin that peels after a sunburn, so I was lucky enough to have happened by just as the process for this one bug was starting. My camera noted the time as 4:27 pm.
In a process that seems motionless but obviously involves moving, the bright orange adult bug squeezes out of its old shell. As the legs become free, the bug stretches them to full length and then rested for a little while.
Here is a wide view, showing the molting bug, another bug's shed, and the group of bugs nearby.
The bug continues to emerge: it reaches up for the leaf with its hind legs for support as the wing tips and the rest of the abdomen pull free.
End of molt was at 4:59, so the process took about 32 minutes to complete.
Here is the newly molted adult
viewed from above
before the colors have darkened.
Nearby was an earlier molted adult with its antennae quivering; possibly sensing another sexually mature individual in close proximity?
The following day, many have molted though many haven't in this mixed aggregation; the rate of maturity among milkweed bugs varies by several days.