Applebaum, S.W., Faculty of Agriculture, The Hebrew University, Rehovot, Israel
Southgate, B.J., Pest Infestation Laboratory, Agricultural Research Council, London Road, Slough, Bucks. England, United Kingdom
Podoler, H., Faculty of Agriculture, The Hebrew University, Rehovot, Israel

Strains of Callosobruchus chinensis (L.) from Israel and Japan which had been in culture for several years were compared. The main morphological differences were that the Japanese strain had the male antennae pectinate, the pubescence of the median lobes of the prothorax completely white, and a dark patch on each of the hind femora. The israeli strain had the male antennae strongly serrate, golden pubescence on the anterior part of the prothoracic median lobes, and the hind femora completely testaceous. In inter-strain crosses the F1 and F2 generations were both fertile, and inter-strain fertility and F1 viability was high, without significant differences in reciprocal crosses. No evidence of intra-strain preference in mating was obtained. Attempts to breed both strains on a number of soybean varieties failed, but the Israeli strain showed partial larval development although none reached pupation. An evaluation of the known chemical composition of soybean was undertaken and by compounding artificial beans and attempting to breed C. chinensis in them, further evidence on the incompatibility of the species with this legume was obtained. This was compared with the breeding rate of Tribolium castaneum, an insect known to be insensitive to the extremes of protein and carbohydrate concentration as are found in soybeans. The evidence indicates that C. chinensis does not present a hazard to soybean production, but the genetic nature of the Israeli strain may have economic implications. © 1968.