COMPARATIVE SUITABILITY OF SOYBEAN AND COWPEA AS HOST PLANTS FOR THE BROWN COWPEA COREID BUG, CLAVIGRALLA-TOMENTOSICOLLIS STAL (HEM, COREIDAE)

Suitability of the pods of cowpea (Vigna unguiculata (L.) Walp) and so ybean (Glycine max (L.) Merrill) as food for Clavigralla tomentosicoll is was determined in the laboratory using development, food substituti on and host switch experiments. On soybean pods, nymphs survived for 8 days and adults for 12 days; on cowpea, all nymphal instars developed into adults and lived for 80-100 days. Teneral adults that were switc hed from cowpea to soybean lost weight, while adults that were moved f rom soybean to cowpea gained weight with slight differences between th e sexes. The shortest critical survival threshold (duration with at le ast 50% survival) of adults on cowpea was greater than the longest on soybean. The likelihood of C. tomentosicollis exploiting soybean as a trophic niche in areas of tropical Africa where production of this cro p is on the increase and usually contiguous with cowpea production, is discussed.