The predacious mites Amblyseius gossipi El-Badry and A. swirskii Athias-Henroit developed, survived and reproduced successfully on several artificial diets. The best diet consisted of 1 g yeast, 1 g milk, 30 mg cystine, 30 mg proline, 30 mg arginine, 20 mg sucrose, 50 mg glucose, 30 mg streptomycin sulphate and droplets of sorbic acid. Mean eggs/female/day by the two predators was 0.54 and 0.30 when reared on the best diet compared to 1.21 and 0.40 when fed on a natural diet, respectively. Female longevity of A. swirskii was 84.3 days, nearly twice as long as that on a natural diet Eggs showed no abnormalities; larvae fed on diets had normal development, and adults were comparable in size to individuals reared on a natural diet.

The nutrition, growth, development and mortality of the cotton leafworm, Spodoptera littoralis, were followed on six different artificial diets. As compared with the reference diet of Poitout et al. (1972) (Entomologia exp. appl.15, 341–350), our new media exhibit some interesting technical features:

(1) The agar is replaced by a new gelling substrate of which two types exist: Korano gels 400 and 411.

(2) These gels allow the preparation of a dry, sterile and ready-to-use mixture in convenient plastic packings. The powder is obtained by grinding the insoluble components and the nebulization of the soluble ones. When needed, the powder is simply added to hot distilled water (60–70°C) and stirred.

Different conditioning processes have been tested and this work was carried out to ensure that the two Korano gelling powders have the same biological quality as agar. The prepacked diets have proven to be very easy to store and to handle, and overall they are quite efficient and time-saving. Furthermore, they are much cheaper than the laboratory-prepared control diet. They supported the complete and normal development of S. littoralis, and even at a slightly better rate than agar-containing diets (M1 and M2b diets).

The shootfly, Atherigona soccata Rondani, is a major seedling pest of sorghum in many areas of tropical Asia, Africa and Mediterranean Europe. A chronological review of the progress made in various programmes on the screening techniques (natural and artificial) with artificial diets, sources, stability and mechanisms of resistance, bases (physico-morphological and biochemical factors) of resistance, inheritance and breeding for resistance is made. Many resistant varieties have been identified and sources of resistance utilized in breeding programmes to transfer resistance in high yielding background are listed. In addition, the glossy and trichome traits identified is sorghum cultivars are also reported. Glossy leaf surface and trichomes are frequently associated with shootfly resistance.

This paper reviews work on techniques in mass rearing of insect pests, especially stem- and pod-borers. The account covers advances in rearing of insects on native host plants and on artificial diets and possible ways of use of these insects in host plant resistance research.