Western Aster Root Aphid(Aphis armoraciae)Common Name: Western aster root aphid
Latin Name: Pemphigus populivenae / Aphis armoraciae
Appearance:
Adults have round, soft bodies with paired cornicles and long, thin mouthparts and are less than 1mm long.
Tiny green eggs are placed in the bark cracks of Populus trees.
Nymphs are like adults but are more translucent and have thinner bodies.
Host plant:
Aspen, cottonwood, other Populus trees in the summer, and various herbaceous wildflowers, including Aster.
Damages caused by Western aster root aphid:
Aphids have tiny mouthparts to pierce plant cells and slurp out the contents. Aster root aphids feast on the plant roots over the summer, weakening the plant and causing wilt and death. Infestations near the plant’s crown may cause the top to fall off. Root aphids exude a waxy, honeydew-like fluid on the roots as they consume. Aphids visit Populus trees in the fall, where they form galls in the leaf petioles. While these aphids cause early leaf drop, they are not considered an economic pest by foresters since they feed late in the season and do minimal damage.
Life history and habitat:
Each aphid can produce 40-60 offspring and lay several aphid eggs or wingless nymphs on each plant upon which they land. Aphids reach sexual maturity in 7-10 days. They are usually all born female and can reproduce asexually without needing male fertilization. They are also a parthenogenetic species that can be born pregnant, which allows for telescoping generations.
