Patterns of limiting similarity in tropical forest tiger beetles (Coleoptera: Cicindelidae)
Biotropica
1980
Journal Article
12
3
195-204
Plants Vascular plants Spermatophytes Angiosperms Animals Invertebrates Arthropods Insects beetles Coleoptera climate seasonality tiger beetles Carabidae Cicindelidae morphology ecology large spatial scales Madre de Dios Bibliography
Sympatric tiger beetles in tropical forests comprise one of the few insect assemblages to exhibit patterns of limiting similarity, principally known for vertebrates (Hutchinsonian ratios). On 10 sites in the Old World (Borneo, New Guinea, Gabon) and New World tropics (Costa Rica, Panama, Ecuador, Peru, Bolivia), the most similar-sized sympatric tiger beetle species had a median mandible length (chord) ratio of 1.35. This ratio was the smallest on sites with more than three ground or undergrowth species (x = 1.26) and largest on sites with only two such species (x = 1.36). It was also small among species on the same site that foraged for insect prey on different substrates (ground, undergrowth leaves, tree trunks, etc.). Mandible ratios on sites with only two common species that were both ground-foragers were significantly greater than expected from random matches of tiger beetle species pairs. Populations of species that occurred on more than one site all varied geographically in mandible length but showed consistent mandible ratios (?1.35) with the most similar-sized congener on each site. Preliminary base resource sampling by sticky traps showed a generally similar abundance and size distribution among sites during the initial part of the rainy season. Marked seasonal differences in insect abundance and size range from site to site likely influenced the number of tiger beetle species per plot. The number of dry months (<150 mm hivin x monthly rainfall) was inversely correlated with the number of ground and low foliage foraging tiger beetle species on each plot.