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Development of Gryon gnidus (Nixon) (Hymenoptera: Scelionidae) in eggs of Acanthomia tomentosicollis (Stål) (Hemiptera: Coreidae) killed either by gamma irradiation or by freezing

Published online by Cambridge University Press:  10 July 2009

R. I. Egwuatu  and
T. Ajibola Taylor
R. I. Egwuatu
Affiliation:
Legume Entomology Research Unit, Department of Agricultural Biology, University of lbadan, Ibadan, Nigeria
T. Ajibola Taylor
Affiliation:
Legume Entomology Research Unit, Department of Agricultural Biology, University of lbadan, Ibadan, Nigeria
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Abstract

Abstract

The effects of host quality on the development of Gryon gnidus (Nixon), a scelionid egg-parasite of Acanthomia tomentosicollis (Stål), are reported. A minimum exposure period of 24 h at —4°C or an irradiation dose of 1000 rads from a cobalt-60 source killed 98–99% of freshly-deposited, fertile eggs of A. tomentosicollis. Sub-lethal periods of exposure delayed hatching in both treatments and the incubation period was increased from 4 days to 5–7 days in eggs exposed to freezing temperature and 4–7 days in irradiated eggs. About 44% of the fertile, untreated eggs hatched normally while 56% were parasitised by G. gnidus. The irradiated or frozen eggs did not hatch and were not parasitised by G. gnidus, thus indicating that G. gnidus would not parasitise dead eggs of A. tomentosicollis. The significance of these results is discussed.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 67 , Issue 1 , March 1977 , pp. 31 - 33
Copyright
Copyright © Cambridge University Press 1977

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