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Superparasitism by Collyria calcitrator, Grav

Published online by Cambridge University Press:  10 July 2009

George Salt
Affiliation:
Imperial Institute of Entomology.

Extract

(1) It has been assumed that parasites oviposit in their hosts purely at random, not discriminating between healthy hosts and those already parasitized.

(2) Only one Collyria calcitrator can develop in each Cephus pygmaeus so that parasites of this species ovipositing in hosts already parasitized endanger or doom their progeny.

(3) 3,761 larvae of Cephus pygmaeus were dissected; 1,049 were unparasitized and 2,712 were parasitized by Collyria calcitrator; 2,195 contained one, 332 two, 98 three, 49 four, 18 five, 7 six, 4 seven, 5 eight, 2 nine, 1 eleven, and 1 sixteen parasites.

(4) These observed data do not agree, even when corrected for several factors, with the values to be expected from random distribution of the eggs one at a time.

(5) The observed data indicate a degree of discrimination on the part of the ovipositing females.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1932

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References

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