Milkweed Aphids

Description:

It is thought that the oleander aphid is an obligate parthenogenetic species; thus the adult aphids are all female and males do not occur in the wild. Adult females may be winged or wingless. The winged adult females (alata) are yellow and black with dark wing veins while the wingless forms (apterae) are yellow with black cornicles, antennae, legs, and cauda (tip of abdomen). Nymphs are similar to apterae in appearance except that they are smaller. Size ranges from 1.5 to 2.6 mm in length. Females are viviparous and parthenogenetic, meaning that they deposit nymphs rather than eggs and that the progeny are clones of the adult female. The nymphs feed gregariously on the plant terminal in a colony that can become quite large. Nymphs progress through five nymphal instars. As in all Sternorrhyncha, there is no pupal stage and adults are produced from the final nymphal instar. Normally apterous adults are produced but alate adults occur under conditions of overcrowding and when plants are senescing so that they can migrate to new host plants. The parthenogenetic mode of reproduction, high fecundity, and short generation time allow large colonies of oleander aphids to build quickly on infested plants.

Habitat:

Milkweed