FLORAL HERBIVORY, FLORAL PHENOLOGY, VISITATION RATE, AND FRUIT-SET INANAXAGOREA-CRASSIPETALA (ANNONACEAE), A LOWLAND RAIN-FOREST TREE OF COSTA-RICA

The flowering phenology, flower production, and insect visitation was determined for Anaxagorea crassipetala in a lowland rain forest study population containing fifty-two trees over 1.5 cm DBH. Flowering of ea ch tree was monitored daily; 71% of the trees in the study population flowered producing a mean of 31.1 flowers/day. Flowers are cauliflorou s, pendant, 2.4-2.7 cm long, with three prominant creamy white, fleshy , outer petals, which represented 63% of floral biomass. Typical of ca ntharophily, flowers were protogynous, fruit-mimicking with a spicy, f ruity fragrance. The perianth formed an enclosure, and rewards consist ed of a protected location. stigmatic exudate, and petals capable of b eing used as a brood substrate. Anthesis commenced at first light, 05: 05, tasting nearly 24 h. The receptive female phase preceeded the brie f pollen-dispersing phase that began 0.5 h before the corolla and andr oecium shattered, ending anthesis. Four species of Coleopterans were f loral visitors, 3 Nitidulidae and 1 Staphylimidae. Visitation rates pe aked with population flowering, but decreased to zero after 33 days. A weevil (Cyrionyx sp.) was observed on buds and petals, and 1014 buds (43% of total) aborted, the result of a weevil larvae feeding in each bud. Fruit flies (Diptera: Drosophilidae) were frequently observed on buds and petals. At anthesis fruit fly larvae were feeding in 100% of outer petals, but no beetle larvae were found. None of the Coleopteran floral visitors carried a pollen load and none of the 1306 flowers wa s pollinated.