The venom apparatus and other morphological characters of the ant Martialis heureka (Hymenoptera, Formicidae, Martialinae)

Carlos Roberto Ferrreira Brandão,Jorge Luis Machado Diniz,Rodrigo Machado Feitosa

doi:10.1590/s0031-10492010002600001

Carlos Roberto Ferrreira Brandão, Jorge Luis Machado Diniz + Show 1 more

Open Access

https://doi.org/10.1590/s0031-10492010002600001

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Abstract

We describe and illustrate the venom apparatus and other morphological characters of the recently described Martialis heureka ant worker, a supposedly specialized subterranean predator which could be the sole surviving representative of a highly divergent lineage that arose near the dawn of ant diversification. M. heureka was described as the single species of a genus in the subfamily, Martialinae Rabeling and Verhaagh, known from a single worker. However because the authors had available a unique specimen, dissections and scanning electron microscopy from coated specimens were not possible. We base our study on two worker individuals collected in Manaus, AM, Brazil in 1998 and maintained in 70% alcohol since then; the ants were partially destroyed because of desiccation during transport to São Paulo and subsequent efforts to rescue them from the vial. We were able to recover two left mandibles, two pronota, one dismembered fore coxa, one meso-metapropodeal complex with the median and hind coxae and trochanters still attached, one postpetiole, two gastric tergites, the pygidium and the almost complete venom apparatus (lacking the gonostylus and anal plate). We illustrate and describe the pieces, and compare M. heureka worker morphology with other basal ant subfamilies, concluding it does merit subfamilial status.

Highlights

The ant Martialis heureka was recently described by Rabeling and Verhaagh based on a single worker collected by Christian Ra‐ beling in Manaus (Embrapa Headquarters 02°53’S, 59°59’W), Amazonas state, Brazil, 28 km of Highway AM 010 in May 9, 2003
The pictures (Figs. 1‐3) we show do not display similar pilosity in comparison to the original Auto‐ montage pictures; summing our information with that presented by Rabeling et al (2008), we can say that in general, pronotum and legs are densely covered with erect to suberect hairs and sparsely with longer erect setae, most of the hairs were lost during scan‐ ning electron microscope (SEM) preparation
Martialis heureka worker mandibles are set very distant from each other in the head capsule, in a simi‐ lar situation to that encountered in Amblyoponinae, or in the ponerine genera Thaumatomyrmex and the isopod hunting species of Leptogenys

Summary

Introduction

The ant Martialis heureka was recently described by Rabeling and Verhaagh (in Rabeling et al 2008) based on a single worker collected by Christian Ra‐ beling in Manaus (Embrapa Headquarters 02°53’S, 59°59’W), Amazonas state, Brazil, 28 km of Highway AM 010 in May 9, 2003. The phylogenetic position of this ant was inferred from several nuclear genes, sequenced from one front leg (Rabeling et al, 2008). 2. Campus Jataí, Unidade Jatobá, Laboratório de Hymenoptera Frei Kempf, Universidade Federal de Goiás, BR 364, km 192, no 3.800, Brandão, C.R.F. et al.: Venom apparatus and morphology of Martialis heureka ant workers arose near the dawn of ant diversification.

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