''Trialeurodes vaporariorum'', commonly known as the glasshouse whitefly or greenhouse whitefly, is an

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

that inhabits the world's

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

regions. Like various other

whiteflies Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described. Description and taxonomy The ...

, it is a primary insect pest of many fruit, vegetable and ornamental

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponic ...

s. It is frequently found in glasshouses (

greenhouse A greenhouse (also called a glasshouse, or, if with sufficient heating, a hothouse) is a structure with walls and roof made chiefly of Transparent ceramics, transparent material, such as glass, in which plants requiring regulated climatic condit ...

s),

polytunnel A polytunnel (also known as a polyhouse, hoop greenhouse or hoophouse, grow tunnel or high tunnel) is a tunnel typically made from steel and covered in polyethylene, usually semi-circular, square or elongated in shape. The interior heats up beca ...

s, and other protected horticultural environments. Adults are 1–2 mm in length, with yellowish bodies and four wax-coated wings held near parallel to the leaf surface.

Life cycle

Females are capable of mating less than 24 hours after emergence and most frequently lay their

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s on the undersides of leaves. Eggs are pale yellow in colour, before turning grey prior to hatching. Newly hatched

nymphs A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are typ ...

, often known as crawlers, are the only mobile immature life-stage. During the first and second nymph instars, the appearance is that of a pale yellow/translucent, flat scale which can be difficult to distinguish with the naked eye. During the fourth and final immature life-stage, referred to as the "

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

", compound eyes and other body tissues become visible as the nymph thickens and rises from the leaf-surface.

Plant damage

All life-stages apart from eggs and "pupae" cause crop damage through direct feeding, inserting their stylet into leaf veins and extracting nourishment from the

phloem Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This tran ...

sap. As a by-product of feeding, honeydew is excreted and that alone can be a second, major source of damage. The third and potentially most harmful characteristic is the ability of adults to transmit several plant

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

es. The crop hosts principally affected are vegetables such as cucurbits,

potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern Unit ...

es and

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

es, although a range of other crop and non-crop plants including

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

species are susceptible, and can therefore harbour the infection.

Control

Effective control has been provided for many years through the release of beneficial insects, such as the aphelinid parasitoid, ''

Encarsia formosa ''Encarsia formosa'' is a species of chalcidoid wasp and a well known parasitoid of greenhouse whitefly, one of the first to be used commercially for biological pest control, from the 1920s. They can use at least 15 species of whitefly as a hos ...

'' (

Gahan Gahan (and its variant Gahame) is a surname with several different origins. One origin of the surname is from a reduced form of '' McGahan'', which is in turn an Anglicised form of the Irish language '' Mac Eacháin'', meaning "son of ''Eachá ...

). If required,

integrated pest management Integrated pest management (IPM), also known as integrated pest control (IPC) is a broad-based approach that integrates both chemical and non-chemical practices for economic control of pests. IPM aims to suppress pest populations below the econ ...

strategies can incorporate applications of selective chemical insecticides or biopesticides such as ''

Lecanicillium muscarium ''Lecanicillium muscarium'' is the approved name of an entomopathogenic fungus species, that was previously widely known as ''Verticillium lecanii'' (Zimmerman) Viegas), but is now understood to be an anamorphic form in the '' Cordyceps'' group ...

'' that complement these natural enemies. For the majority of outdoor crops chemicals are still the most widely used method of control. To study pest resistance management a 787‐Mb high‐quality draft genome has been sequenced and assembled.

References

External links

* *
USDA Whitefly Knowledgebase
{{Taxonbar, from=Q581988 Whiteflies Agricultural pest insects Insects described in 1856