''Encarsia formosa'' is a species of chalcidoid

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder ...

and a well known

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

of greenhouse whitefly, one of the first to be used commercially for

biological pest control Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or ot ...

, from the 1920s. Its use fell with commercial pesticides in the 1940s, but rose again from the 1970s.

Description

The tiny females (about 0.6 mm long) are black with a yellow abdomen and opalescent wings. The species reproduces asexually via

thelytoky Thelytoky (from the Ancient Greek, Greek θῆλυς ''thēlys'' "female" and τόκος ''tókos'' "birth") is a type of parthenogenesis and is the absence of mating and subsequent production of all female diploid offspring as for example in aph ...

induced by

Wolbachia ''Wolbachia'' is a genus of gram-negative bacteria infecting many species of arthropods and filarial nematodes. The symbiotic relationship ranges from parasitism to obligate mutualism. It is one of the most common parasitic microbes of arthrop ...

infection. Males are produced but are unable to inseminate the females. The adults use the clap and fling flight mechanism often seen in sub-mm insects.

Life cycle

Females deposit 50-100 eggs individually inside the bodies of

nymphs A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, land ...

pupa A pupa (; : 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 life cycle, the stages th ...

e of the host species. The wasp larvae develop through four instars in about two weeks at optimum temperatures. Parasitized greenhouse whitefly pupae turn black in about 10 days, while parasitized sweet potato whiteflies turn amber brown. Both are easily distinguished from unparasitized host pupae. Wasp pupation occurs within the whitefly body. Adult wasps emerge about 10 days later. ''E. formosa'' can use at least 15 species of

whitefly 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 A ...

as its host, including '' Bemisia tabaci'' and '' Aleyrodes proletella.''

Use in biological control

''Encarsia formosa'' has been used as a natural pesticide to control

populations in

greenhouse A greenhouse is a structure that is designed to regulate the temperature and humidity of the environment inside. There are different types of greenhouses, but they all have large areas covered with transparent materials that let sunlight pass an ...

s since the 1920s. Use of the insect fell out of fashion due to the increased prevalence of chemical pesticides and was essentially non-existent by the 1940s. Since the 1970s ''E. formosa'' has seen something of a revival, with renewed usage in European and Russian greenhouses. In some countries, such as New Zealand, it is the primary biological control agent used to control greenhouse whiteflies, particularly on crops such as tomato which is a difficult plant for predators to establish themselves on.Bioforce Limited, New Zealand
/ref>

References

{{DEFAULTSORT:Encarsia Formosa Aphelinidae Biological pest control wasps Insects used as insect pest control agents Insects described in 1924 Taxa named by Arthur Burton Gahan