''Brevicoryne brassicae'', commonly known as the cabbage aphid or cabbage aphis, is a destructive aphid (plant louse) native to Europe that is now found in many other areas of the world.Hawaii Department of Entomology information page
/ref> The aphids feed on many varieties of produce, including

cabbage Cabbage, comprising several cultivars of ''Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage ( ''B.&nb ...

, broccoli (especially), Brussels sprouts,

cauliflower Cauliflower is one of several vegetables in the species ''Brassica oleracea'' in the genus ''Brassica'', which is in the Brassicaceae (or mustard) family. It is an annual plant that reproduces by seed. Typically, only the head is eaten – the ...

and many other members of the genus '' Brassica'', but do not feed on plants outside of the family Brassicaceae. The insects entirely avoid plants other than those of Brassicaceae; even though thousands may be eating broccoli near strawberries, the strawberries will be left untouched.University of Minnesota extension
Cabbage aphids, from the genus ''

Brevicoryne ''Brevicoryne'' is a genus of aphid insect that contains many species which are agricultural pests. Hosts This genus parasitizes a wide range of hosts, with many members of the Brassicaceae ( broccoli, cabbage, kale, etc.) included. Adults ...

'' of the family Aphididae, are grayish-green, but a waxy covering gives them a grayish-white to powdery blue appearance.

Predator defense mechanism

Cabbage aphids produce a myrosinase (beta-thioglucoside glucohydrolase) enzyme in head and thoracic

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...

s; the aphids also uptake

glucosinolate Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damaged. T ...

s, particularly sinigrin, from the plants on which they feed, storing the glucosinolates in their haemolymph. (Glucosinolates are natural defenses for plants in the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Brassicales against pests and

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

s.) The combination of the glucosinolates and the myrosinase enzyme produces a violent chemical reaction that releases the mustard oil chemical allyl isothiocyanate.Imperial College London (2007, July 12). Aphids Make 'Chemical Weapons' To Fight Off Killer Ladybirds. ScienceDaily. Retrieved November 20, 2007, from https://www.sciencedaily.com/releases/2007/07/070711105844.htm The defense mechanism has a dramatic negative effect on the survival of the larval ladybird predator '' Adalia bipunctata''. The chemical defence of the aphids has been likened to a " walking mustard oil bomb". The myrosinase from ''Brevicoryne brassicae'' appears to have evolved separately from myrosinases found in plants, possibly a case of convergent evolution. Aphid myrosinase appears to have greater similarity to animal beta-O-glucosidases than to plant myrosinases.

Pest control

Different varieties of cultivars have varying resistance to ''Brevicoryne brassicae''. '' Diaeretiella rapae'' is a common wasp

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

of cabbage aphids. Other controlling insects include

ladybird beetle Coccinellidae () is a widespread family of small beetles ranging in size from . They are commonly known as ladybugs in North America and ladybirds in Great Britain. Some entomologists prefer the names ladybird beetles or lady beetles as th ...

syrphid fly Hover flies, also called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while ...

larvae, and

lacewing The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera can be grouped together with the Megaloptera and Raphidioptera in t ...

larvae. Some

insecticidal soap Insecticidal soap is used to control many plant insect pests. Soap has been used for more than 200 years as an insect control. Because insecticidal soap works on direct contact with pests via the disruption of cell membranes when the insect is pen ...

s may be effective in treating aphid infestations.

References

External links

Images of cabbage aphids
* * {{Taxonbar, from=Q2634837 Macrosiphini Agricultural pest insects Insect vectors of plant pathogens Insects described in 1758 Hemiptera of Europe Taxa named by Carl Linnaeus