Oviposition and larval survival of Diaprepes abbreviatus (Coleoptera:Curculionidae) on select host plants

In a preliminary survey in four commercial ornamental nurseries in south Florida (1998), Diaprepes abbreuiatus (L.) (Coleoptera: Curculionidae) egg masses, feeding damage, or adults occurred on numerous field-grown ornamental plant species. Live oak (Quercus Virginiana Mill.), silver buttonwood (Conocarpus erectus L. variety sericeus Fors. Ex DC), and black olive (Bucida buseras L.) had the highest percentage of plants with egg masses. Adult feeding damage was found on all examined plants of dahoon holly (Ilex cassine L.), cocoplum (Chrysobalanus icaco L.), black olive, live oak, Bauhinia sp., and Cassia sp. Oviposition of D. abbreviatus was evaluated in no-choice, two-choice, three-choice and multiple-choice caged tests. In no-choice tests, silver buttonwood had the highest mean number of egg masses. In two-choice tests, egg masses were laid on all plant species tested but there were significantly more egg masses on silver buttonwood than the alternate choice. The number of egg masses in the three-choice tests was low and there were no significant differences among the plant species tested. As in the no-choice and two-choice tests, significantly more egg masses were found on silver buttonwood in multiple-choice tests. Survival of larvae and their effect on plant growth was examined on several commonly grown plant species in southern Florida. Larval survival was highest on silver buttonwood and Sorghum sudanense Pers (sorghum-sudan) compared with other plant species. Root and/or total biomass was significantly reduced on green bean (Phaseolus vulgaris), silver buttonwood, Tahiti lime (Citrus aurantifolia), and sorghum-sudan.