Trophic ecology of the armadillo ant,Tatuidris tatusia, assessed by stable isotopes and behavioral observations

Justine Jacquemin,Mark Maraun,Maurice Leponce,Thibaut Delsinne

doi:10.1093/jis/14.1.108

Abstract

Ants of the genus Tatuidris Brown and Kempf (Formicidae: Agroecomyrmecinae) generally occur at low abundances in forests of Central and South America. Their morphological peculiarities, such as mandibular brushes, are presumably linked with specialized predatory habits. Our aims were to (1) assess the Tatuidris abundance in an evergreen premontane forest of Ecuador; (2) detail morphological characteristics and feeding behavior of Tatuidris; and (3) define the position of Tatuidris in the food web. A total of 465 litter samples were collected. For the first time, live Tatuidris individuals were observed. Various potential food sources were offered to them. A nitrogen stable isotope ratio analysis (15N/14N) was conducted on Tatuidris tatusia, other ants, and common organisms from the leaf-litter mesofauna. We found a relatively high abundance of T. tatusia in the site. Live individuals did not feed on any of the food sources offered, as usually observed with diet specialist ants. The isotope analysis revealed that T. tatusia is one of the top predators of the leaf-litter food web.

Highlights

Ants of the genus Tatuidris Brown and Kempf (Formicidae: Agroecomyrmecinae) are rare inhabitants of soil and leaf-litter layers of Neotropical forests from Mexico to French Guiana, central Brazil, and Peru (Donoso 2012; Lacau et al 2012)
Nitrogen stable isotope analysis is of particular value for such an analysis because it makes it possible to define the trophic position of an organism in a food web and that organism’s degree of omnivory
Species abundance 65 individuals were extracted from 79 m2 of leaf litter in November 2009, and 96 individuals from 97.75 m2 of leaf litter in March 2010

Summary

Introduction

Ants of the genus Tatuidris Brown and Kempf (Formicidae: Agroecomyrmecinae) are rare inhabitants of soil and leaf-litter layers of Neotropical forests from Mexico to French Guiana, central Brazil, and Peru (Donoso 2012; Lacau et al 2012). T. tatusia possesses a series of morphological peculiarities, such as modified mandibles, suggesting that Tatuidris are specialist predators (Brown and Kempf 1968). Their feeding habits and trophic position remain unknown. Nitrogen stable isotope analysis is of particular value for such an analysis because it makes it possible to define the trophic position of an organism in a food web and that organism’s degree of omnivory

Objectives

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Results