Occurrence of Three Haplotypes of Linepithema micans (Forel) (Hymenoptera: Formicidae) in Southern Brazil

Abstract

Linepithema micans (Forel) (Hymenoptera: Formicidae) is reported to occur from eastern Brazil to central Argentina in pasture or grassland, forest and second growth riparian forest, nesting under stones, rotting wood, and sandy soil. However, information on this species is poor and its ecological interactions and role as pests are unknown. Linepithema humile (Mayr), a closely related species to L. micans, known as the Argentine ant, is native to South America, and was accidentally introduced to several regions of the world. Recent studies have shown that other related species, such as L. micans, could become as pestiferous as L. humile because of its phylogenetic proximity. Samples of L. micans from different habitats in Southern Brazil were characterized by sequencing of the mitochondrial DNA. Sequences were compared to previously obtained sequences from samples of L. humile and the genetic distance and differences in the tRNALeu structure were investigated. Our data identified three haplotypes of L. micans, two of which were observed in ant populations closely associated with the Brazilian ground pearl Eurhizococcus brasiliensis (Hempel) (Hemiptera: Margarodidae), a soil scale that is a serious pest of vineyards. The third haplotype was identified in ants from populations invading residences in urban habitats.

Occurrence of 15 Haplotypes of Linepithema micans (Hymenoptera: Formicidae) in Southern Brazil

“…However, Sacchett et al (2009) identified many species of ants, including Linepithema micans (Forel 1908), in the vineyards of the Serra Gaucha region that were infested by E. brasiliensis. This result was confirmed in the Brazilian state of Rio Grande do Sul by Martins et al (2012) using molecular techniques. This high visibility of L. humile as the main pest likely stems from the great similarity between the workers of the two species, which causes errors arising from morphology-based identifications (Wild 2007).…”

“…The new findings were deposited in GenBank under accession numbers KM211952-KM211965. For comparison, the haplotypes from Martins et al (2012) were also added to the analyses. The leucine tRNA was identical to the one described by Martins et al (2012) for L. micans.…”

“…The ants were stored in 80% alcohol and chilled to À20 C from the date of collection until the extraction. The extractions followed the protocol of Martins et al (2012).…”

“…Furthermore, the ability of L. micans to adapt to different conditions and ecological roles may be explained by its close phylogenetic relationship with L. humile (Wild 2009). This raises the possibility that this species may also display eruptive population dynamics in its native environment (Martins et al 2012).…”

“…Sequencing mtDNA fragments is a frequent tool to distinguish different haplotypes and to understand evolutionary processes. Martins et al (2012) characterized mitochondrial fragments (partial COI, tRNAleu, and partial COII) in populations of L. micans in southern Brazil and identified three different haplotypes. The present study aims to expand the knowledge of haplotype diversity and distribution in the region of state of Rio Grande do Sul (Brazil), in an attempt to understand the genetic differences of the populations identified in this study.…”