The aggregation of Chauliognathus species (Coleoptera, Cantharidae) and its possible role for coexistence and mimicry

Vilmar Machado,Aldo Mellender De Araújo

doi:10.1590/s0073-47212001000200002

Abstract

The relative population sizes of a species complex of Chauliognathus are reported, as well as their spatial distribution associated with different patches of food plants. Field work was done at Fazenda Santa Isabel, municipality of Guaíba, State of Rio Grande do Sul, Brazil. The results suggest that two mechanisms account for the reduction in food competition among the species involved: one is asynchrony in the appearance of the species in the area, and the other is aggregation in different patches of food plants. Since the species here reported show a similar colour pattern (yellow-black) the possibility of the occurrence of serial mimicry in this complex of species is dicussed.

Highlights

Aggregation on food sources has been registered for several insect species
The results here reported could be viewed in the light of two ecological-evolutionary theories: competition and mimicry (BLOSSEY, 1995; SILLEN-TULBERG & HUNTER, 1996)
The findings suggest that two mechanisms could account for the reduction in the food competition among the species involved; one is the asynchrony in the appearance of the species in the area

Summary

Introduction

Aggregation on food sources has been registered for several insect species Such aggregations consist of species of the same genus (ATKINSON & SHORROCKS, 1984; ROSEWELL et al, 1990; BLOSSEY, 1995). Data on the recruitment rates of the species Chauliognathus flavipes Fabricius, 1781, C. expansus Waterhouse, 1878, C. octomaculatus Pic, 1915, C. fallax Germar, 1824, C. lineatus Zwetsch & Machado, 2000 and C. tetrapunctatus Zwetsch & Machado, 2000 are reported. Information on their spatial distribution, associated with different patches of food plants are analyzed. Other species of Chauliognathus occurred sporadically in the area; they did not belong to the “yellow-black” mimicry complex

Methods

Results

Conclusion