Whiteflies+are+not+actual+flies

By: G. Alexopoulos


 * Taxonomy:**

Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Hemiptera Suborder: Sternorrhycha Super family: Aleyrodoidea Family: Aleyrodidae

Whiteflies have about 1550 species described within the family Aleyrodidae, the only family within the superfamily Aleyrodoidea. Not actually flies these insects are small hemipterans.


 * Description and l**** ife cycle: **

Whiteflies like the Greenhouse whitefly (//Trialeurodes vaporariorum//) is a common pest within cultivated greenhouses. Typically they reside on the underside of leaves where the adults 1-2mm in length and yellowish bodies with four wax-coated wings feed on the plant leaf vein.

Twentyfour hours after emerginf from their eggs whitefly females of the Greenhouse whitefly (//Trialeurodes vaporariorum//) are able to mate and frequently deposit their eggs on the underside of leaves. Pale and yellowish in color after laying these eggs turn to grey before hatching. Each female has the ability to lay up to 200 eggs. The hatched larvae are the only mobile immature life stage, the first and second stages or instars are flat scale in appearance and can be difficult to see. The fourth instar stage is pupa like rising off the leaf surface and developing eyes and other bodyparts become visible. This however is not a true pupa stage as hemipterans do not develop into pupa stages.


 * Prey and predation:**

All lifestages of the whitefly extract plant sap rich in sugars and nutrients called phloem with their sucking mouth part called a stylet. In large whitefly infestations plants can get overwhelmed. A by-product called honeydew is excreted as result of feeding. Honeydew can cause a mold on the host plant like sooty mold which can damage the plant by blocking sunlight to the leaves. Whiteflies are also sources for a number of plant viruses transmitting these diseases as they feed. Some viruses are able to completely kill off plant species which can decimate greenhouse and other agricultural crops.

A number of species consume whiteflies at their various lifestages. Additionally, parasitic predators of whiteflies lay their eggs on them. To name a few predators green lacewings, ladybirds, minute pirate bugs (as seen above), and parasitic wasps like //Eretmocerus eremicus.//


 * Ecological and human impact:**

Able to carry and spread diseases, whiteflies impact food production globally. The whitefly problem is most serious in the tropics and subtropic zones. Aleyrodidae cause hundreds of millions of dollars in economic losses. Shown to be able to transmit almost 60 viral plant diseases, whiteflies sometimes carry viruses able to infect a number of different plant species. Whiteflies also provided food for predator species and limit plant growth and facilitate environmental change with plant death. Additionally, their ability to cause plant diseases has cause humans to search for a number of ways in order to control them. Insecticides, bio controls like certain fungus and bacteria, as well as insect controls by introduction of predators.