Isoenzyme variation in the leaf-cutting ants Acromyrmex heyeri and Acromyrmex striatus (Hymenoptera, formicidae)

Elena Diehl,Suzana Cavalli-Molina,Aldo Mellender De Araújo

doi:10.1590/s1415-47572002000200010

Abstract

This is the first study of isoenzyme variability in the leaf-cutting ants (Myrmicinae, Attini) Acromyrmex heyeri (Forel, 1899) and A. striatus (Roger, 1863) which are common throughout the southern Brazilian state of Rio Grande do Sul. We studied the alloenzyme variability of malate dehydrogenase (MDH), α-glycerophosphate dehydrogenase (α-GPDH) and amylase (AMY) in 97 colonies of A. heyeri and 103 colonies of A. striatus. Five loci were found for these enzyme systems, one locus (Amy-1) being monomorphic in both species and four loci (Mdh-1, α-Gpdh-1, Amy-2, and Amy-4) being polymorphic. For each species there were exclusive alleles for the Mdh-1 and Amy-2 loci and differences were also found in the allele frequencies for the other polymorphic loci. Ontogenetically different gene activity was detected for the MDH and α-GPDH systems, with between-caste differences, probably related to flight activity, also being found for α-GPDH.

Highlights

Leaf-cutting ants of the genus Acromyrmex are drawing increasing attention because of the damage they cause to crops
In Brazil, A. heyeri and A. striatus are restricted to the southern states, with the greatest concentration of these species being in the Rio Grande do Sul, the southernmost Brazilian state
In this paper we report on the isoenzyme patterns, genetic control and alloenzyme variability of malate dehydrogenase, α-glycerophosphate dehydrogenase and amylase in these ants

Summary

Introduction

Leaf-cutting ants of the genus Acromyrmex are drawing increasing attention because of the damage they cause to crops. Due to the great morphological polymorphism of the species and the considerable variability found among individuals, Acromyrmex is one of the most complex genera of the family Formicidae. The head and thorax spines are important systematic characters, but their proportions can vary between and within colonies, individuals with bilateral asymmetry of the head being very common. According to Gonçalves (1961), this variability was referred to by Emery (1905) and Santschi (1925) who revised the genus. There are behavioral differences between these two species, including nest architecture and stability, seasonal and daily activity, and worker mobility. In Brazil, A. heyeri and A. striatus are restricted to the southern states, with the greatest concentration of these species being in the Rio Grande do Sul, the southernmost Brazilian state

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