As I’ve mentioned before on this blog, I usually have aphids in early spring, and then the predators and parasitoids knock them back to almost nothing through the summer.
But somehow, the predators and I all missed the aphids on the pumpkins. I expect the warm dry summer was perfect for their growth. I rarely take note of the pumpkins from December to April—they need little weeding, and are generally pest free.
So when I went to harvest, it was a bit of a surprise to find millions of aphids on the underside of nearly every leaf in a back corner of the pumpkin patch.
All summer, the aphids have been cloning themselves, producing dozens of replicas every week—an army of little green girls. Only girls. It wouldn’t have taken them long to build up the population level out there right now. Some of the generations of aphids had wings (you can see some on the left side of the leaf in the photo), and dispersed to other plants, but most stayed put, slowly spreading across one leaf after another.
But, as big as the population is today, they will all die over winter. About this time of year, the females will start producing a few males—also genetically identical to themselves, with the exception of a missing sex chromosome. Only in the fall will females mate and produce eggs. The eggs will overwinter, hatching out in spring (all female) to start the cycle over again.
I think I won’t wait for these girls to lay eggs. I’m afraid that, now that the pumpkins are gone, the infested vines will be dunked in a bucket of soapy water and buried deep in the compost pile. No sense in letting them get a head start on next spring!