Critical stages of mortality were egg and larva during the rainy season and larva and pupae during the dry season.
The ability to store male pupae for some time before emergence and irradiation provides a useful degree of flexibility in operational programmes.
Pupae at the three sites were placed between two layers of hardware cloth (1 cm mesh) to protect against mice and bird predation.
The pupae collected from each of the cultures were placed in clean plastic containers and adults were provided with 20% honey-water as food upon emergence.
The glass jars were placed in an environmental growth chamber maintained under the same conditions as described for pupae, and held until adult emergence.
Up to eight weeks after treatment, no pupae were recorded in any of the three treatments.
The independence of site and depth for combined counts of prepupae and pupae from each spring-summer period at each site was tested by log-linear analysis.
The figures in parentheses represent the predicted or observed number of day-degrees accumulated by larvae/ pupae since the start of the investigation.
