Abundance vs. Efficiency: The Role of Apis mellifera and Trigona spinipes in the Pollination of the Star Fruit Tree (Averrhoa carambola L.)

Résumé fourni par la source

The star fruit tree (Averrhoa carambola L.) has knowledge gaps regarding its reproductive dynamics and interactions with pollinators under field conditions. This study aimed to characterize the phenology, floral biology, and efficiency of biotic visitors in fruit set in Brazil. Flowering occurred from December to February (~90 days), with synchrony among individuals. The flowers are hermaphroditic, ephemeral (with a longevity of 12 h), and exhibit morning anthesis (07:00), with stigmatic receptivity maintained throughout the floral opening period. Floral density was high, with an average of 21.22 ± 11.36 flowers per inflorescence. The visiting entomofauna was predominantly Hymenoptera (95.3%), with Trigona spinipes (58.3%) and Apis mellifera (37%) the most prominent. However, resource segregation was observed: T. spinipes acted primarily as a resin collector, while A. mellifera collected nectar exclusively, exhibiting a significantly higher foraging rate (10.15 ± 1.28 flowers/min) compared to T. spinipes (4.69 ± 1.40 flowers/min). In pollination tests, there was a significant difference (p < 0.05) between all treatments: pollination directed by A. mellifera resulted in the highest initial fruit set (3.1%), followed by free pollination (1.9%) and wind/phyllo pollination (1.2%). Total isolation (paper bags) produced only 0.5% of fruits, confirming that spontaneous self-pollination is inefficient due to floral morphology. It is concluded that, despite the abundance of T. spinipes, it does not effectively contribute to pollination because it focuses on non-reproductive resources. A. mellifera is the most efficient pollinator. Its targeted introduction is essential to mitigate pollination deficits and increase star fruit productivity.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.