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Whitefly
Whiteflies (Trialeurodes vaporariorum)
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Homoptera
Suborder: Sternorrhyncha
Superfamily: Aleyrodoidea
Family: Aleyrodidae
Subfamilies

Aleurodicinae
Aleyrodinae

The whiteflies, comprising only the family Aleyrodidae, are small homopterans. Trialeurodes vaporariorum, commonly known as the glasshouse or greenhouse whitefly inhabits the world’s Temperate regions Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Hemiptera is an order of Insects comprising around 80000 Species of Cicadas Aphids Planthoppers Leafhoppers The Sternorrhyncha is the suborder of the Hemiptera which contains the Aphids whiteflies, and Scale insects groups which were traditionally Hemiptera is an order of Insects comprising around 80000 Species of Cicadas Aphids Planthoppers Leafhoppers More than 1550 species have been described. Whiteflies typically feed on the underside of plant leaves.

Contents

Agricultural threat

While feeding damage can cause economic losses, it is the ability of whiteflies to transmit or spread viruses that has had the widest impact on global food production. In the tropics and subtropics, whiteflies (Hemiptera: Aleyrodidae) have become one of the most serious crop protection problems. Hemiptera is an order of Insects comprising around 80000 Species of Cicadas Aphids Planthoppers Leafhoppers The whiteflies, comprising only the family Aleyrodidae, are small Homopterans More than 1550 species have been described Economic losses are estimated in the hundreds of millions of dollars. While several species of whitefly cause crop losses through direct feeding, a species complex, or group of whiteflies in the genus Bemisia are important in the transmission of plant diseases. Bemisia tabaci and B. argentifolii, transmit African cassava mosaic, bean golden mosaic, bean dwarf mosaic, bean calico mosaic, tomato yellow leaf-curl, tomato mottle, and other Begomoviruses, in the Family: Geminiviridae. Geminiviruses are Plant viruses which have Ambisense single-stranded Circular DNA genomes and are members of class II of the Baltimore classification The world-wide spread of emerging biotypes, such as B. tabaci biotype B, also known as, 'B. argentifolii', and a new biotype Q, continue to cause severe crop losses which will likely continue to increase, resulting in higher pesticide use on many crops (tomatoes, beans, cassava, cotton, cucurbits, potatoes, sweet potatoes). Efforts to develop integrated pest management, IPM, systems aimed at environmentally friendly strategies to also reduce insecticide use will help re-establish the ecological equilibrium of predators, parasitoids, and microbial controls that were once in place. New crop varieties are also being developed with increased tolerance to the whiteflies, and to the whitefly-transmitted plant diseases. A major problem is the fact that the whiteflies and the viruses they carry can infect many different host plants, including agricultural crops and weeds. This is complicated by the difficulty in classifying and detecting new whitefly biotypes and Begomoviruses. Proper diagnosis of plant diseases depends on using sophisticated molecular techniques to detect and characterize the viruses and whiteflies which are present in a crop. A team of researchers, extension agents and growers working together are needed to follow disease development, using dynamic modeling, to understand the incidence of disease spread.

In 1997 Tomato yellow leaf-curl begomovirus, TYLCV was discovered in the USA, in Florida. This plant disease is the worst viral disease of tomato. The disease is transmitted by the whitefly, Bemisia argentifolii. The whitefly is also been shown to transmit almost all of the 60 known whitefly transmitted plant viral diseases.

Whitefly damage by feeding: Whiteflies feed by tapping into the phloem of plants, exposing plants to the whiteflies' toxic saliva and decreasing the plant's overall turgor pressure. In Vascular plants phloem is the living tissue that carries organic Nutrients (known as photosynthate particularly Sucrose, a sugar to For the band see Saliva (band; for the village in Azerbaijan see Səliva. ' Turgor pressure' or turgidity is the main pressure of the cell contents against the Cell wall in Plant cells and bacteria cells determined by the water The damage is quickly elevated as whiteflies congregate in large numbers, quickly overwhelming susceptible plants. Damage is further exacerbated as whitesflies, like aphids, excrete honeydew as a waste product, which promotes mold growth and may seriously impede the ability of farms to process cotton harvests. Honeydew is a Sugar -rich sticky substance secreted by Aphids and some Scale insects as they feed on Plant sap. WikipediaManual_of_Style#National_varieties_of_English --> Molds (or

Whiteflies share modified form of hemimetabolous metamorphosis, in that the immature stages begin life as mobile individuals, but soon attach to a host plant. Metamorphosis is a Biological process by which an Animal physically develops after Birth or hatching involving a conspicuous and relatively The stage before the adult is called a pupa, though it shares little in common with the pupal stage of holometabolous insects. A pupa ( Latin pupa for doll pl pupae or pupas) is the life stage of some Insects undergoing transformation Holometabolism, also called complete metamorphism, is a term applied to insect groups to describe the specific kind of insect development which includes four

Control

Whitefly control is difficult and complex, as they rapidly gain resistance to chemical pesticides. Pest control refers to the regulation or management of a Species defined as a pest, usually because it is perceived to be detrimental to a person's Health A pesticide is a substance or mixture of substances used to kill a pest. The USDA recommends "an integrated program that focuses on prevention and relies on cultural and biological control methods when possible. " [1] Use of yellow sticky traps to monitor infestations and only selective use of insecticides is advised.

Companion plants

Various companion plants are reputed to repel or trap white flies. Companion planting in gardening and agriculture is planting of different crops in close physical proximity on the theory that they will help each other Calendula like marigolds do so for documented reason, producing chemicals that repel them. Calendula ( Ca-lén-du-la, pot marigold) is a genus of about 12-20 species of annual or perennial Herbaceous Nasturtiums are thought to have a similar effect, while mint may serve either as a repellant or trap crop. Basil, too, has a reputation for repelling them, which may be due to its production of several essential oils that are known to drive away insects, including citronella. An essential oil is a concentrated Hydrophobic Liquid containing volatile Aroma compounds from Plants They are also known as volatile

See also

greenfly, aphid, leafhopper, thrips

References

External links

Dictionary

whitefly

-noun

  1. Any of various small insects of the family Aleyrodidae that have long wings, and a white body; often a garden pest
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