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Competencia por Territorios Alimenticios en Dos Especies de Moscas Ricárdidos Neotropicales¹: Experimento de Exclusión en Campo

Becerril-Morales, Felipe
TheSouthwestern entomologist 2019 v.44 no.1 pp. 261-269
Diptera, Eupatorium, Neotropics, bags, forage, host plants, phylogeny, territoriality
It is generally assumed that phytophagous species do not usually compete for food, however this can be questioned in the case of phylogenetically related species. Through an exclusion experiment, the value of the food resource and the corresponding occurrence of territorial behavior between two species of richardid dipterans Odontomera nitens (Schiner 1868) and O. ferruginea (Macquart 1844) were determined. The feeding sites were experimentally excluded by tulle bags, systematically distributed in the host plant Eupatorium collinum De Candolle (1836), (Asteracea). Data were collected on frequency and intensity of fights (event in which an individual showed aggressive displays); variables such species, sex, abundance, and intrusion-residence role were registered. Two experiments were done in which the conditions of exclusion and free access to the resource were alternated. The results suggest that feeding sites were a limiting resource and that this may be related to the sex of those who own the feeding site. It is discussed a possible alternation between the exploitative and the interference competition according to the situation of the forage population and the availability of the resource.