Published online by Cambridge University Press: 10 July 2009
Hodotermes mossambicus (Hagen) is a harvester termite which competes with livestock for natural grazing. Control by baiting is recommended. Field trials in the north-western Orange Free State and south-western Transvaal, Republic of South Africa, showed that the two most commonly used commercial baits, with carbaryl or sodium fluosilicate as the active ingredient, are ineffective in controlling this species. A simple mathematical model was developed to rate the acceptability of grasses as food for the termite colonies. This enabled the attractiveness of the bait carriers as food for termites to be compared with that of the grasses. All five grass species tested had a similar food acceptability value, while both bait carriers were unacceptable as food. Failure of the baits was due to the fact that they were not consumed by the termites. The active ingredients was found to be effective when natural grass was used as the bait carrier. The mathematical model was extended to elucidate the effect of different baits on colony survival. This approach could be further used to rate new baits and their carriers objectively.