Dense packing of oleander aphids leads to physical changes, such as the wing pads seen in some of these individuals. Click image to enlarge.
East central Illinois’ recent drought conditions have been particularly stressful on plants.
We typically find an abundance of field bindweed (Convolvulus arvensis) along our west and south fences adjoining the neighboring fields.
Heavy feeding and asexual reproduction of oleander aphids on the few surviving bindweed plants have resulted in aphid densities well beyond the norm.
The adult aphids, all female, are viviparous (giving birth directly to young, thus bypassing an external egg stage) and parthenogenic (meaning fertilization does not occur, so the progeny are clones of the adult female).
The offspring typically develop into wingless adults, though overcrowding and aging/stress of host plants can lead to production of winged adults. Note the development of wing pads on some of these young aphids.
It will be interesting to see how the bindweed is impacted over the next several days.
