Cactoblastis cactorum is a polyphagous feeder, attacking a wide range of Opuntia species within the subgenus Platyopuntia. Recent studies evaluating oviposition preference of C. cactorum females mated with irradiated and non-irradiated males reported no significant differences due to radiation treatment or interaction between radiation treatment and cactus species. However, the proportion of egg sticks oviposited on cactus species differed significantly. As a result, we evaluated host suitability of several cactus species in this study to determine if reproductively inactivated C. cactorum could be used to predict host range.

A variety of whole plants were placed in individual cages with a single egg stick. Resulting larvae were allowed to develop until pupation, after which they were removed. Pupae were placed in emergence cages until adults emerged. Larval survival and developmental time were recorded to estimate host suitability.