Screening selected cowpea, Vigna unguiculata (L.) Walp., lines for resistance to Lygus hesperus (Heteroptera:Miridae)

Eighty-six cowpea, V. unguiculata (L.) Walp., acquisitions were screened for indications of resistance to L. hesperus Knight in individual plant cages. Observed gross rate of population increase and reduced proportional development of L. hesperus to an advanced instar or the adult stage were used as indications of resistance. Significantly fewer total bugs were recovered from 35 of the cowpea test entries than from the susceptible entries. On some entries, a majority of L. hesperus recovered from cages were in the 5th instar or adult stage, whereas significantly greater proportions of lygus bugs recovered from 15 of the entries were in the earlier instars, indicating delayed development. Twenty-two entries appear to be worthy of more intensive evaluation for level and mechanism of resistance to this insect.