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How to Manage Pests:
Pest Management and Identification
Encarsia formosa
Scientific name: Encarsia formosa
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Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Aphelinidae
Common Hosts: Parasitic on several whitefly species including
the greenhouse whitefly, sweetpotato whitefly and silverleaf whitefly.
Used for control of greenhouse whiteflies in greenhouses, for floricultural
and nursery plants, strawberries,
and tomatoes.
Commercially available: Yes
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Encarsia formosa, an endoparasitic wasp, is the most important
parasite of the greenhouse whitefly. Adult female Encarsia formosa are
tiny wasps (<1 mm in length) with a dark brown to black head and
thorax and a bright yellow abdomen. Males are dark in color, but
are rare. Adult females host feed on all immature stages by puncturing
the body with their ovipositors and consuming the exuding blood.
Eggs are laid into third and fourth-instar whiteflies and hatch into
larvae that feed within the whitefly nymph and grow through three
larval instars before killing the host. Greenhouse whitefly nymphs
turn dark brown or black approximately one week after being parasitized
and their skin forms a black pupal case for the parasite. Silverleaf
whiteflies parasitized by E. formosa stay lighter in color
and do not turn black. Like many whitefly parasites, E. formosa leaves
a circular hole and black feces in the host remains. In contrast,
emerging whiteflies leave a ragged or T-shaped emergence hole in
their mostly clear or whitish pupal skin.
E. formosa is used for whitefly control in greenhouses
on tomatoes, strawberries and in floricultural and nursery plants.
Biological control of the greenhouse whitefly can often be provided
in enclosed areas by introducing sufficient numbers of commercially
available E. formosa. Release programs of Encarsia formosa are
most effective when the initial population of whiteflies is quite
low (only a few whiteflies per plant) and long-residual insecticides
have not been applied in advance of the parasite release. For biological
control to be successful use more selective and less persistent
insecticides, and control ants since they disrupt the oviposition
of E. formosa.
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