Ecological relationships betweenCeratitisspp. (Diptera: Tephritidae) and other native fruit tree pests in southern Mozambique

Abstract

Introduction . Insect pest identification and understanding of insect pest ecological relationships constitute a basic step for any control measure needed. Some native fruit trees occur naturally in southern Mozambique and the edible fruits are sought after by local communities. Our study aimed at assessing the activity of native fruit tree insect pests during the year and their ecological relationships, providing, for the first time, a faunistic analysis of insect species affecting fruit trees in the region of Maputo, Mozambique. Materials and methods . Entomological surveys were carried out between June 2002 and December 2003 in the Districts of Manhica, Marracuene, Namaacha and Matutuine (southern Mozambique). Quadrangular 900-m2 plots were established in fields where Annona senegalensis, Garcinia livingstonei and Vangueria infausta native fruit trees naturally occurred. The number of individual insect pests per fruit, tree and plot was recorded to estimate ecological fauna measurements: the affinity index, association index and simultaneous constancy. Results and conclusion . A total of 1648 insect specimens, belonging to eight insect species, were found while conducting the ecological observations on Annona senegalensis Pers (Annonaceae), Garcinia livingstonei T. Anders (Clusiaceae) and Vangueria infausta Burch (Rubiaceae). Two groups of pests were observed: defoliators and insects attacking the fruits, which represented the majority. Affinity between insect species was observed, with the relationship between Ceratitis capitata Wiedemann and one unidentified species of the Cosmopterigidae family reaching the highest values. C. capitata was also found to have the highest association index with Spatulipalpia monstrosa Balinsky (Lepidoptera: Pyralidae), as well as Carpophilus sp. (Coleoptera: Nitidulidae) and Araecerus sp. (Coleoptera: Curculionidae). C. capitata and Araecerus sp. had the highest simultaneous occurrence in different locations. Cluster analysis also indicated that Ceratitis capitata and Carpophilus sp. had the highest similarity percentage in all samples.