SUMMARY We have generated an antibody which is absolutely specific for H. armigera over H. punctigera. Specificity has been demonstrated in a number of ways. For example, the antigenic protein from H. armigera and its homologue from H. punctigera were purified and probed with the kit MAb. No detectable reaction was observed against H. puncti.gera under conditions where a very strong reaction was observed versus the H. armigera protein. The experiments indicate that a very high level of species-specificity is an inherent property of the kit antibody. We have incorporated the anti.body into a prototype ID kit which has now been tested under field conditions. The kit is not yet of commercial quality and reliability. Nevertheless, for eggs collected from the field at a single time and place, there is a high correlation between the % H. armigera detennined by the kit and as determined by rearing (Trowell et al. 1992). This indicates that the basic design of the kit is sound and further development is worthwhile. We are working on reliability problems which have been thrown up in the field tests and have made significant progress in overcoming them. The problems are of the kind normally encountered in development of this type of test kit Together with a partner experienced in immunodiagnostic production, we expect to be able to produce a kit of commercial quality