Cabbage whitefly recently discovered in California
Click here for the enlargement of |
this photo or for
Name: Aleyrodes proletella Linnaeus
Animalia: Arthropoda: Insecta: Homoptera: Aleyrodidae
Common Names: cabbage whitefly; Brassica whitefly
The cabbage white fly, previously reported* in Massachusetts and Vermont, was detected for the first time in California (Santa Cruz County) in July 2001.
Issues of Concern: The degree of economic impact this pest may have on California crops is unknown. It could potentially reduce plant vigor by its feeding activity and/or inflict cosmetic damage by exuding honey dew, thereby causing the growth of sooty mold on the plants. It does not, however, seem to be a major economic pest in the Northeast U.S. or other parts of the world. The cabbage whitefly is not considered a greenhouse pest, nor is it known to vector plant viruses.
The current California infestation is undergoing eradication.
The nearly cosmopolitan distribution of this originally Palaeoarctic pest demonstrates its ability to invade new areas. It has a wide host range, feeding on plants in at least 12 different families. Numerous important crop plants are among its preferred hosts.
The cabbage whitefly may be spread by trade-related movement of its host plants. In addition, long-distance wind dispersal is common in whiteflies, and is therefore also a possibility.
Hosts: Aleyrodes proletella is polyphagous, feeding on herbaceous plants in numerous families including (but not limited to) Apiaceae, Asteraceae, Balsminaceae, Brassicaceae, Campanulaceae, Euphorbiaceae, Fabaceae, Fagaceae, Papveraceae, Rununculaceae, Scrophulariaceae. Among its preferred hosts are cabbage, brussel sprouts, cauliflower, broccoli and kale.
Africa (Canary Islands, Egypt, Morocco, Mozambique); Asia (Russia, Taiwan); Atlantic Islands (Bermuda); Australia; Europe (Austria, England, Czechoslavakia, Finland, France, Germany, Hungary, Italy, Poland, Spain, Sweden, Switzerland, Yugoslavia); New Zealand; South America (Brazil)
All life stages are usually found on the underside of leaves. Yellow sticky cards can be used to monitor flying adults.
Adults are ca. 1.5mm long with two dark marks on each wing. Pupae are yellowish brown and very similar to those of the Iris whiteflly, A. spiraeoides. Nymphs are scale-like and covered with wax. They are white with two yellow spots on the abdomen. Eggs are laid upright in a semicircle on the underside of leaves. Egg-laying takes place from mid-May to September. The entire life-cycle takes ca. one month. There are usually 4 to 5 generations per year.
The cabbage whitefly was reported as a new pest in Australia in 1997.
It is sometimes also referred to as Aleyrodes brassicae Walker.
*Skinner, M. 1993. A New Whitefly in Our Midst. The Grower: Vegetable and Small Fruit Newsletter 93(1), 5; National Agricultural Library Call Number SB321 G85
De Barro, P.J. & Carver, M. 1997. Cabbage Whitefly, Aleyrodes proletella (L.) (Hemiptera: Aleyrodidae), Newly Discovered in Australia. Australian Journal of Entomology. 36: 255-256
Williams, T. 1995. The Biology of Encarsia tricolor: An Autoparasite of Whitefly. Biological Control 5: 209-217
USDA Whitefly Knowledge Database
Warning: The information in this archived item was not confirmed with the appropriate National Plant Protection Organization and is provided solely for informational purposes. Please use this information with caution.