Factors Affecting the Resistance of Certain Cucurbits to the Squash Borer1

Abstract

Infestations of Melittia cucurbitae on 13 vars. of squash and pumpkin revealed marked differences in oviposltional preferences, larval survival and plant tolerance. Resistance generally appeared to follow specific lines. Cucurbita moschata vars. were highly resistant because of avoidance by ovipositing females and a low rate of larval establishment following both artificial and natural infestation. C. pepo vars. were moderately resistant, while C. maxima vars. were least resistant to larval attack and to the subsequent entrance of decay organisms. Differences in stem anatomy were also correlated with differential resistance to insect attack. All C. moschata vars. were characterized by a small woody stem having large, closely ranged vascular bundles. Infestations of other insect pests also differed between the spp. and vars. of Cucurbita studied.