Van Dijken, M.J., & van Alphen, J.J.M. 1991a Sex allocation in Epidinocarsis lopezi: the influence of host-size distribution and its effect on the population sex ratio in cassava fields in Africa.. Redia 74(3): 195-201.

Notes: [Proceedings of the 4th European Workshop, Insect Parasitoids-Tritropihic Interactions (F. Bin, Ed.), held in Perugia, Italy, April 3-5, 1991.] In cassava fields in Africa, population sex ratios of Epidinocarsis lopezi, used as a biological control agent against the cassava mealybug Phenacoccus manihoti, were variable and highly male-based at high host densities. This variability is caused by the difference in allocation of sons and daughters to hosts of different sizes. The sex ratio increases with host density for three reasons: the proportion of small hosts encountered in the field increases with increasing host density, small hosts are used for male production and hosts are always accepted when encountered. In the same way the variable, often male-biased sex ratios present in the mass-rearing of this species is explained.