van Dijken, M., van Stratum, P., & van Alphen, J.J.M. 1988 Sex ratio studies in Epidinocarsis lopezi: local mate competition.. Mededelingen van de Faculteit Landbouwwetenschappen, Rijksuniversiteit Gent 53(3a): 1097-1108.

Notes: [In XXXX International Symposium on Crop Protection, Gent.] An evolutionary approach towards sex allocation was used to study the highly variable sex ratio of the encyrtid Epidinocarsis lopezi, a parasitoid of the pseudococcid Phenacoccus manihoti in the laboratory at 25.5 deg C and 45% RH and in cassava fields in Nigeria. There was no significant difference between the sex ratios of eggs laid by 1, 2, 4 or 8 parasitoids exploiting a patch of 12 3rd-instar host nymphs in a Petri dish. Significantly fewer eggs were laid per parasitoid when 4 or 8 parasitoids were searching together. Sex allocation did not change during superparasitism. For 4 or 8 parasitoids exploiting a patch the sex ratio of emerging progeny was lower (fewer males) than that of the eggs laid. In the field, mating appeared to be random. It is concluded that local mate competition does not operate in E. lopezi and that superparasitism leads to a more female-biased sex ratio.