HPIPM:Leafy Brassicas (Greens)Aphids

Author: Whitney S. Cranshaw

Taxonomy

Domain	Eukarya
Kingdom	Animalia
Phylum	Arthropoda
Subphylum	Hexapoda
Class	Insecta
Subclass	Pterygota
Infraclass	Neoptera
Superorder	Paraneoptera
Order	Hemiptera
Suborder	Sternorrhyncha
Infraorder	Aphidomorpha
Superfamily	Aphidoidea
Family	Aphididae
Subfamily	Aphidinae
Tribe	Macrosiphini
Genus	Myzus
Subgenus	Nectarosiphon

Scientific Name

Myzus persicae

Common Name

green peach aphid

Cabbage aphid Brevicoryne brassicae) Turnip aphid(Lipaphis pseudobrassicae) Green peach aphid Myzus persicae)

Identification (and life cycle/seasonal history)

During summer the life cycle of the cabbage-infesting aphids is similar to that of other aphids. Female aphids give live birth to daughter aphids and no sexual reproduction occurs. Aphids may mature in less than two weeks under summer temperatures and can produce several young daily for a period of a couple of weeks. In the absence of natural controls aphid populations increase rapidly. Cabbage aphids and turnip aphids solely develop on mustard family plants. Winter is spent on winter annual mustard weeds or surviving crop debris of cole crops. Green peach aphid has a much wider range of summer hosts and is important on several vegetable crops, including pepper, potato, and lettuce. Green peach aphid host alternates during the cool season months and winters as an egg stage on various stone fruits, such as peach, apricot, and certain plums. The three cabbage-infesting aphids can be distinguished, in part, by the way covering on the insect. Cabbage aphid is blue-gray and covered with fine wax particles. Wax also covers the body of the turnip aphid, which ranges in shades of brown. Green peach aphid does not have the powdery wax cover, is smooth bodied and is often straw colored.

Plant Response to Damage

Cabbage aphid feeding on expanding leaves causes twisting and discoloration. Aphids can also be serious contaminant of marketed heads and is very commonly damaging to Brussels sprouts. Turnip aphid and green peach aphid are much less damaging to growth of cole crops. Problems with these species sometimes occur with contamination of produce.

Natural Controls

Aphids can be heavily attacked by several natural enemies. Parasitic wasps are perhaps the most conspicuous of these, causing aphids to swell and stick to plants when dead, a form known as an 'aphid mummy'. General predators include larvae of syrphid (flower) flies, damsel bugs, and minute pirate bugs. Green lacewing larvae and lady beetles also feed on aphids, although cabbage aphid is not a preferred host.

Cultural Control

Overwintering crop debris of cole crops should be destroyed to eliminate cabbage aphid winter hosts.

Chemical Control

Plant coverage is critical to aphid control since aphids can locate in folds of developing leaves. Insecticides with systemic activity can improve coverage and provide better control. Almost all insecticides used on crucifers suggest use of wetting agents to improve coverage due to the waxy leaves.

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.