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Aphidius
matricariae
A braconid wasp that parasitizes
aphid nymphs
Photography by Max E. Badgley
(1922-2006)
| Aphidius matricariae adult, parasitizing an
aphid nymph |
| Photo ©
Max E. Badgley, published with
permission from the Max E. Badgley Estate, with special thanks to
the University of California, Riverside, who kindly supplied this
image from the UCR Chalcidoidea database collection. |
Numerous species of wasps are included in the genus Aphidius,
but all attack and control aphids. Aphidius matricariae is reared
in commercial insectaries, generally for greenhouse use.
All species of Aphidius are minute, braconid wasps whose females
lay single eggs in the bodies of live aphid nymphs. The wasp larvae feed
on the aphid host's tissues, eventually killing the host as they mature
and, in the process, cementing the aphid carcass to the plant. The dead
aphids turn black and mummify, thereupon serving as pupae for the wasp
larvae. When the wasp's pupal stage is complete, adult wasps emerge from
their mummy casings by cutting a hole in the aphid mummy. The empty
aphid mummy remains attached to the plant, and the exit hole used by the
wasp can easily be seen under magnification.
It is a good practice to examine infestations of aphids for mummies in
their midst. Such a sight tells an observer that the aphids on that
plant are under attack by natural predators and that many, if not most, of
the remaining live aphids are presently parasitized and will soon die.
Text compiled and edited
by J.Cates, curator
Badgley Photography
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