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Mantidfly - Dicromantispa sayi

Mantidfly - Dicromantispa sayi
St. Lucie County, Florida, USA
April 22, 2005
Cocoon removed from audax egg sac.

Images of this individual: tag all
Mantidfly - Dicromantispa sayi Mantidfly - Dicromantispa sayi Mantidfly - Dicromantispa sayi Mantidfly - Dicromantispa sayi Mantidfly - Dicromantispa sayi

Moved from Dicromantispa.

Moved from Mantispa.

#25295 Identification -- Dicromantispa sp. (cocoon)
This is the cocoon of a mantispid of the genus Dicromantispa, probably sayi.

spider egg parisitism
I just found a mantispid cocoon and the resulting adult in the housing container of a captive Phidippus texanus female. The female was captured as an adult in the wild, and I brought her into the lab hoping for some young to rear. She promply deposited a clutch of eggs for me, but when I examined the nest web a month later, I found only the empty cocoon surrounded by shriveled husks of the devoured eggs. Further searching led me to the exoskeleton of the mantispid (it in turn was devoured by mommy texanus after it emerged). I don't know whether it's been assumed that mantispids lay eggs in the nest of their hosts, but this can't be the case here, as my spider was isolated in my lab within a sealed container prior to ovoposition. So, this mantispid must lay an egg on (or within) female spiders, and this egg is later deposited into the nest as the spider lays her eggs. Pretty wild, huh!

Yes it is
I have had four mantidfly invasions to date. Two clarus and two audax. Three were already in field collected egg cases, and the first was similar to your experience.
What kind of work are you doing with Phidippus?
Here is a brief summary of their larval behavior in case you are not familiar...

Annual Review of Entomology
Vol. 43: 175-194 (Volume publication date January 1998)

Kurt E. Redborg­
Department of Biology, Coe College, 1220 First Avenue NE, Cedar Rapids, Iowa 52402; e-mail:

Members of the Neuropteran family Mantispidae, subfamily Mantispinae, are predators in the egg sacs of spiders, draining egg contents through a piercing/sucking tube formed by modified mandibles and maxillae. First-instar mantispids use two strategies to locate spider eggs: Larvae may burrow directly through the silk of egg sacs they find, or they may board and be carried by female spiders prior to sac production, entering the sac as it is being constructed. Mantispids that board spiders usually adopt positions on or near the pedicel; some species may enter the spider's book lungs. Larvae maintain themselves aboard spiders by feeding on spider blood. Transfers of larvae from spider to spider are possible during spider mating or cannibalism. All of the major groups of hunting spiders are attacked by spider-boarding mantispids; the egg sacs of web-building species are also entered by egg-sac penetrators

Phidippus research
I just submitted a master's thesis on the reproductive/courtship behaviors of P. carolinensis and P. audax, and also looked at aspects of polyandry (females mating w/multiple males) in P. audax. Miss texanus was a specimen I brought in from one of my field surveys earlier this year.

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