The conservation and sustainable management of Annona coriacea requires knowledge of its floral and reproductive biology, and of its main pollinators and their life cycles. In this work, we analyzed these aspects in detail. Floral biology was assessed by observing flowers from the beginning of anthesis to senescence. The visiting hours and behavior of floral visitors in the floral chamber were recorded, as were the sites of oviposition. Excavations were undertaken around specimens of A. coriacea to determine the location of immature pollinators. Anthesis was nocturnal, starting at sunset, and lasted for 52–56 h. The flowers were bisexual, protogynous and emitted a strong scent similar to the plant´s own ripe fruit. There was pronounced synchrony among all floral events (the period and duration of stigmatic receptivity, release of odor, pollen release and drooping flowers) in different individuals, but no synchrony in the same individuals. All of the flowers monitored were visited by beetle species of the genera Cyclocephala and Arriguttia. Beetles arrived at the flowers with their bodies covered in pollen and these pollen grains were transferred to the stigmata while foraging on nutritious tissues at the base of the petals. With dehiscence of the stamens and retention within the floral chamber, the bodies of the floral visitors were again covered with pollen which they carried to newly opened flowers, thus promoting the cycle of pollination. After leaving the flowers, female beetles often excavated holes in the soil to lay eggs. Larvae were found between the leaf litter and the first layer of soil under specimens of A. coriacea. Cyclocephala beetles were the main pollinators of A. coriacea, but Arriguttia brevissima was also considered a pollinator and is the first species of this genus to be observed in Annonaceae flowers. Annona coriacea was found to be self-compatible with a low reproductive efficiency in the area studied. The results of this investigation provide ecological data that should contribute to the conservation and economic exploitation of A. coriacea.

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HIPÓLITO FERREIRA PAULINO-NETO 2 RESUMO -Anonáceas, em geral, são espécies cantarófilas e altamente especializadas, apresentando pétalas espessas, carnosas e nutritivas que formam uma câmara floral com ocorrência de termogênege. Este estudo objetivou verificar os efetivos polinizadores e sistema reprodutivo prevalente em A. coriacea. Flores foram marcadas e acompanhadas durante períodos do dia e da noite para verificar os polinizadores legítimos. Tratamentos de polinização manual foram realizados para determinar o sistema reprodutivo. Besouros escarabeídeos Cyclocephala atricapilla e Cyclocephala quatuordecimpunctata (Dynastinae) foram atraídos pelo odor emitido pelas flores no início da noite já contendo pólen em seus corpos e penetraram na câmara floral, onde permaneceram por até 48h alimentando-se das pétalas e de pólen, copulando, e ao tocarem nos estigmas receptivos, depositaram pólen. Posteriormente, flores em fase masculina liberaram pólen que novamente sujou o corpo dos besouros e, com a queda da flor, voaram para outra flor recém-aberta e em fase feminina, iniciando novo ciclo de polinização. A. coriacea é uma espécie autocompatível e Cyclocephala foram polinizadores muito eficientes. Termos para indexação: Annona coriacea, autocompatibilidade, Cerrado, Cyclocephala, polinização por besouros. POLLINATION AND REPRODUCTIVE BIOLOGY OF ARATICUM-LISO (Annona coriacea Mart.: ANNONACEAE) IN A SAVANNA AREA: IMPLICATION TO FRUIT GROWINGABSTRACT -Anonaceous, in general, are cantharophilous highly specialized, presenting thick, fleshy and nutritious petals forming a floral chamber with thermogenese occurrence. This study aimed to verify the effective pollinators and prevalent breeding system in A. coriacea. Flowers were marked and accompanied during day and night periods to verify legitimate pollinators. Treatments of hand pollination were done to determine the breeding system. Scarab beetles Cyclocephala atricapilla and Cyclocephala quatuordecimpunctata (Dynastinae) were attracted by the scent exhaled by flowers in the beginning of the night already containing pollen on their bodies and penetrated into floral chamber, where stayed until 48 h feeding on the petals and shed pollen, copulating and when they touched the receptive stigmas, deposited pollen. Afterwards, flower in male phase released pollen that once more got the beetle bodies dirty and with the flower fall they flied to new-open flower and in female phase starting new pollination cycle. A. coriacea is a self-compatible species and Cyclocephala were considered very efficient pollinators.