Cuphea lanceolata and Cuphea ignia Seed Increase Using Three Pollinators in Insect-Proof Cages in the Field

Oil from seed of many Cuphea (Lythraceae) species is abundant in medium-chain fatty acids (C8-C14). The fatty acids are valuable to industry and obtained from petrochemicals and tropical plants. Cuphea could provide a valuable temperate plant source of fatty acids, but there are agronomic limitations to commercial production. Many Cuphea spp. are entomophilous, so finding suitable pollinators will enhance development of the crop. In the study, the pollinating ability of three insects, honey bee, Apis mellifera L.; bumble bee, Bombus bimaculatus Cresson; and horned-face bee, Osmia cornifrons (Radoszkowski), were tested on Cuphea lanceolata W.T. Aiton and Cuphea ignia A. DC in insect-proof cages in the field. Based on harvested seed weight, the honey bee was an efficient pollinator of C. lanceolata with significantly more seed produced (40.9 g) than the no-pollinator check (9.8 g). The honey bee was not significantly different than the bumble bee (20.7 g) or O. cornifrons (25.6 g). The honey bee also was an efficient pollinator of C. ignia, with significantly more seed produced than any other pollinator. Bombus spp. are excellent pollinators of Cuphea, but our results indicated B. bimaculatus was an inefficient pollinator of C. ignia in field cages.