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SEX RATIO VARIABILITY OF MUSCIDIFURAX ZARAPTOR (HYMENOPTERA: PTEROMALIDAE)1

Published online by Cambridge University Press:  31 May 2012

H. G. Wylie
Affiliation:
Research Station, Agriculture Canada, Winnipeg, Manitoba R3T 2M9

Abstract

Females of Muscidifurax zaraptor K. & L. produce a smaller percentage of female progeny as the ratio of ovipositing females to hosts (house fly pupae) increases. Delays in oviposition are apparently responsible for the sex ratio change, because they reduce the percentage of fertilized eggs, i.e. female eggs, that the parasites lay. Delays increase in frequency as the parasite:host ratio increases, and result mostly from interference among the ovipositing females; the interference is mostly or entirely physical. Solitary females of M. zaraptor produce slightly fewer though not significantly fewer female progeny when low host densities delay oviposition; more tests would be required to confirm this effect. There is no evidence for differential survival of the male and female parasite larvae on superparasitized hosts.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1979

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