Green fruit visitor insects of Annona senegalensis Pers. (Magnoliales: Annonaceae) and their potential role in the plant fruiting

Abstract

Abstract Annona senegalensis Pers. (Annonaceae) is a wild shrub used multipurposely in food and traditional medicine by local people in African tropical countries. During its fruiting period, especially at the green fruit stage, this plant harbors an important community of insects such as the planthopper Hilda undata (Tettigometridae) and various ant species (Formicidae). This study aimed at understanding the interactions between ants, Hilda undata and the plant Annona senegalensis. Green fruit insect visitors of A. senegalensis were collected randomly from 30 green fruits of 30 plants per site, at four sites across the Sudanian and Sudano-Sahelian climatic zones of Burkina Faso during the green fruit stage of the plant, from June to July. The behavior of green fruit visiting insects was observed in the field. In addition, ants and Hilda undata were collected and their whole body sugars were analyzed. Ants were the most recorded visiting insect group, representing up to 95% of the insects observed on the fruit. The orders of insects recorded were Coleoptera, Diptera, Hemiptera, Hymenoptera and Lepidoptera and the most frequently encountered species were Trichomyrmex abyssinicus, Crematogaster sp (Formicidae), Messor galla (Formicidae), Brachyponera sennaarensis (Formicidae) and H. undata. Behavioural observations showed that ants consume extrafloral nectar from green fruits and honeydew from H. undata. The ants would protect the green fruits from their pests and H. undata from its natural enemies. This study is the first report highlighting mutualistic interactions between A. senegalensis, ants and H. undata.