Cabbage Aphid (Brevicoryne brassicae)

Description

These aphids are soft-bodied, with piercing-sucking mouthparts. Adults can take on two forms: winged and wingless. Wingless adults are 0.1 inches long, oval-shaped, and have a grayish-green or grayish-white waxy covering. Eight dark brown or black spots are also located beneath the waxy coating on the abdominal surface. Winged females are smaller than their wingless counterparts and lack waxy covering. The wings are short, and the head and thorax are black or dark brown with dark brown antennae. Their abdomen is yellow, with two dark spots on the dorsal abdominal segments merging into a dark band across the last abdominal segment.

Other Common Names: Cabbage aphis

Distribution: Native: Europe; Invasive: Canada, China, India, South Africa, and the Netherlands

Habitat: Gardens and farmlands

Do they bite: No

Lifespan: 16-50 days

Predator: Ladybugs, parasitic wasps, and syrphid fly larvae

Behavior and Characteristics

Feeding

These aphids feed on plants in the genus Brassica, including broccoli, Brussels sprouts, cabbage, and cauliflower.

Defensive

Cabbage aphids secrete a myrosinase naturally from their heads and thoraxes and absorb chemicals, like sinigrin, from the plants they feed on. The combination of all these chemicals allows them to release the mustard oil chemical, allyl isothiocyanate, compared to a “walking mustard oil bomb”.

Life Cycle

These aphids reproduce in two ways depending on the climate. In warm climates, females undergo parthenogenesis and give birth to female nymphs, while in temperate climates, mating occurs with the females laying eggs afterward.

1. Egg Stage

Female cabbage aphids lay eggs on plant debris.

2. Nymph Stage

This stage lasts for 7-10 days.

Getting Rid of Them

Biological control measures include natural predators like ladybird beetles, while other methods include spraying insecticides on potential host plants.