Featured Pest: The Spiraling Whitefly (Aleurodicus dispersus)

 Hosts:

Recorded on 38 genera of plants from 27 plant families and over 100 different species.

The Spiraling Whitefly (Aleurodicus dispersus) has proven to be a nuisance and have caused damage to native vegetation. Photo credit: Scot Nelson, http://www.ctahr.hawaii.edu/nelsons/Misc/1_ Plumeria_spiraling_whitefly_1.jpg.

The Spiraling Whitefly (Aleurodicus dispersus) has proven to be a nuisance and have caused damage to native vegetation.
Photo credit: Scot Nelson, http://www.ctahr.hawaii.edu/nelsons/Misc/1_
Plumeria_spiraling_whitefly_1.jpg.

Common on vegetables, ornamental, fruit and shade tree crops in Hawaii, including avocado, banana, bird-or-paradise, breadfruit, citrus, coconut, eggplant, kamani, Indian banyan, macadamia, mango, palm, paperbark, papaya, pepper, pikake, plumeria, poinsettia, rose, sea grape, ti, and tropical almond.

Distribution:

Native to Central American and the Caribbean region.  First reported in Hawaii in 1978 and now present on all of the major islands.

Damage: 

a) Direct – damage caused by piercing and sucking of sap from foliage.  Majority of feeding done during the first three nymphal stages.  Usually insufficient to kill plants.

b) Indirect – damage due to accumulated honeydew and white, waxy flocculent material.  The honeydew serves as a substrate for sooty mold, which blackens the leaf and decreases photosynthesis and plant vigor, and can cause disfigurement.  The flocculent material is spread by the wind and can create an unsightly nuisance.

c) Virus transmission – damage from virus transmission can be considerable.  These viruses cause over 40 diseases of vegetable and fiber crops worldwide.

 Management:

This insect thrives in warm, dry weather.  Heavy rains and cool temperatures may reduce populations.

a) Non-chemical control – five natural enemies were introduced into Hawaii from the Caribbean to control whitefly populations.  One of the three coccinellid beetles (ladybugs) has proved effective with high population densities of whitefly.  Two parasitic wasps have proven effective against low populations of whitefly.  These biological controls generally provide adequate control to minimize damage to plants.

b) Chemical control – contact and systemic insecticides recommended for other pests on the same plant hosts may temporarily reduce whitefly populations.  However, such insecticides may also harm whitefly predators and so should be avoided where possible.

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References:

Kessing, Jayma L. Martin, and Mau, Ronald F.L. 1993. Crop Knowledge Master Aleurodicus dispersus (Russell). http://www.extento.hawaii.edu/kbase/crop/Type/a_disper.htm.

 

Photo:

Scot Nelson, http://www.ctahr.hawaii.edu/nelsons/Misc/1_Plumeria_spiraling_whitefly_1.jpg

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About the author  ⁄ Chauncey Hirose-Hulbert

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