Abundance and community composition of flower visiting insects of avocado (Persea americana Mill) in the East African region

Abstract

Pollination of avocado flowers is essential for fruit production and is facilitated by various insect taxa. Currently, there is limited information available on the community structure of the pollinators of avocado crops in East Africa. We duly present the distinct groups of insects visiting avocado flowers across two most important avocado producing countries in the East African region. Insects were swept from avocado flowers along transects and sorted by morphological features that classified them into orders, families, and genera. Five common orders were identified, namely: Coleoptera, Diptera, Heteroptera, Hymenoptera, and Lepidoptera. The relative abundance of Hymenoptera and Diptera were highest (49% and 22% respectively) hence we further identified them to the families and genera taxonomic groups. Three Dipteran families were found (Calliphoridae, Muscidae, and Syrphidae) from which we recognized five genera: Chrysomya, Spilogona, Eristalinus, Phytomia and Syritta. Hymenoptera on the other hand were placed into two general groups; bees and wasps. For bees, family Apidae was represented by Apis, Ceratina, Meliponula, and Xylocopa whereas seven diverse wasp families (Braconidae, Philanthidae, Vespidae, Ichneumonidae, Eumeninae, Thynnidae and Pompilidae) were also noted. The occurrence of Coleoptera and Lepidoptera varied across the three orchards while the rest of the orders remained unaffected. We further recorded the insect’s potential pollinator functions and concluded that the main pollinators of avocado flowers in the region are members of Syrphidae and Apidae families. This information serves as a foundation for avocado pollination studies in the East African region that are important for improving pollination services and insect pollinators’ conservation.