Parasitoids of Bemisia spp.
There are five parasitoid genera of wasps that are known
to parasitize the Bemisia spp. complex. Whiteflies that are parasitized by these wasps are
often identified by a round emergence hole in the whitefly pupal case.
Amitus (Platygasteridae, Platygasteroidea)
Encarsia (Aphelinidae, Chalcidoidea)
Eretmocerus (Aphelinidae, Chalcidoidea)
Signiphora (Signiphoridae, Chalcidoidea)
Metaphycus (Encyrtidae, Chalcidoidea)
Encarsia and
Eretmocerus are the two main parasitoid genera attacking
Bemisia complex species.
Genus Encarsia (Aphelinidae)
This genus comprises over 200 species. The majority of the species in this genus parasitize whiteflies, others parasitize diaspine scales and a very few
have been reared from aphids and lepidopterous eggs.
Twenty-two described and at least 3 undescribed species have been reared from Bemisia
tabaci. Males of many of the Encarsia species are adelphoparasites, ie. males develop
on the females of their own or different species. Members of this genus have 6 funicle segments (5 in some
males), the tarsal formula is usually 5-5-5 (5 segments on each
of the 3 tarsi) but several that attack B. tabaci are 5-4-5.
There are 36 described and many undescribed species in this genus. The genus is currently under revision. Both male and female
of the known Eretmocerus species are primary parasitoids. Members of this genus are easily recognized by the two
short funicle segments (absent
in the male), long antennal club and the 4-4-4 tarsal
formula.
One species of each of the genera Amitus, Metaphycus and Signiphora
have been reared from B. tabaci. Signiphora aleyrodis Ashmead is a hyperparasitoid, probably parasitizing Eretmocerus and Encarsia inside the
whitefly nymph. The Metaphycus species is an
undescribed species from Venezuela. This genus otherwise has always been found parasitizing
scale insects (Coccoidea). Amitus bennetti Viggiani and
Evans was discovered in Puerto Rico and has been introduced into Florida, California and Israel.
Genus Signiphora (Signiphoridae)
There are 18 described species and many undescribed species in
this genus. Signiphora aleyrodis Ashmead is the
common species reared from Bemisia tabaci. It is a hyperparasitoid of Encarsia or Eretmocerus species
parasitizing the host whitefly
nymph. Members of this genus are easily recognized by their
bare fore wing with long marginal fringe, 3-segmented funicle and long antennal
club, and 5-5-5 tarsal
formula. S. aleyrodis is yellow with dark, transverse bands across the mesosoma (abdomen). The fore wing also has a dark brown band across the
middle.
Genus Amitus (Platygasteridae)
There are 17 described species, all of which are parasitoids of whiteflies. Amitus bennetti Viggiani and
Evans is the only species that has been reared from Bemisia tabaci. Males of this species
are rare. Members of this genus are readily distinguished from
other whitefly parasitoid genera by the 8-segmented antenna flagellum (the last 3
segments are fused together to form a club in the female), large,
black, sclerotized body, and the lack of the marginal and stigmal
veins in the fore wing.
Genus Metaphycus (Encyrtidae)
There are over 200 described species in this genus, however there is only 1 bona-fide record of a species
(undescribed) of this genus parasitizing a whitefly. Species of
this genus are known from scale insects (Coccoidea).
Metaphycus is easily distinguished from the other B. tabaci parasites by its 11 segmented antenna (9 in the
male), very short marginal vein, and axillae that meet together at the center of its body.
Management Menu
Main Menu
Parts of this material may be reproduced for educational use. Please credit "United States
Department
of Agriculture, WHITEFLY KNOWLEDGEBASE"
