Effect of mango weevil (Coleoptera : Curculionidae) damage on mango seed viability in Hawaii

The mango weevil, Cryptorhynchus (=Sternochetus) mangiferae (F.), is a fede rally quarantined pest that prevents shipment of mangos from Hawaii into th e continental United States. Although this monophagous weevil allegedly cau ses reduced seed germination, damage to the fruit pulp, and premature fruit drop in mangos, there are few studies examining these potential sources of crop loss. We conducted studies to assess the effect of mango weevil infes tation on seed viability while making observations on the frequency of pulp feeding. Naturally infested seeds from mature fruit were planted in pots a nd scored for successful germination. Germination rates for infested seeds were equal to those of uninfested control seeds in a polyembryonic cultivar ('Common'), whereas germination was significantly reduced for infested see ds of a monoembryonic cultivar ('Haden') compared with uninfested control s eeds but germination of infested seeds was still >70%. To assess seed toler ance of damage, seeds were artificially damaged by cutting away 25, 50, or 75% of the cotyledon It fore planting and scored for germination. None of t he damage treatments was significantly different from the undamaged control s, indicating that mango seeds can withstand substantial damage and still g erminate successfully. Over the 2-yr period we conducted experiments, only four of 3,602 mango fruits (0.11%) showed evidence of direct feeding damage to the pulp. Results suggest that C. mangiferae is less serious pest of ma ngos than previously thought.