Foxglove Aphid

Foxglove aphid is usually light green with dark green spots at the base of the cornicles (projections from the rear of the abdomen) but has several color forms, ranging from green to orange to pink. Aphid adults can have winged or wingless forms; winged adults will disperse. Some of the wingless aphids have many black markings on the top of the abdomen as well. The winged adults are browner than the wingless forms but also have various black markings. Nymphs are always wingless.

Foxglove aphid has a wide host plant range and can rapidly increase in number because it has a very short life cycle. In regions of the California Central Coast where celery and lettuce are grown, foxglove aphid can be a prolific pest that moves between these crops. Foxglove aphid is nearly indistinguishable in the field from the lettuce aphid (Nasonovia ribis-nigri), which is not an economically important pest of celery. And both the foxglove aphid and lettuce aphid can be distinguished from another common aphid, the green peach aphid, by the absence converging antennal tubercles; a magnifying hand lens may be needed to see the green peach aphid’s definitive indentation between the two antennal segments. Foxglove aphid lacks this trait.

Foxglove aphids feed deep inside the plant on younger leaves. It can vector several viral diseases.

Monitoring requires care in order not to miss early infestations that are hidden within the celery. Foxglove aphid tends to disperse in the plant rather than form colonies as green peach aphid does. Controlling foxglove aphid is difficult because of its rapid population growth combined with its preferred locations deep within the plant.