ID guide | introduced ants

Rapid increase of the parasitic fungus Laboulbenia formicarum in supercolonies of the invasive garden ant Lasius neglectus

Publication Type:Journal Article
Year of Publication:2015
Authors:S. Tragust, Feldhaar, H., Espadaler, X., Pedersen, J. Søe
Journal:Biological Invasions
Date Published:Mar-06-2015
Keywords:Epizootiology, Host–parasite interaction, Invasive species, Laboulbeniales, social insects, Unicoloniality

A key feature among invasive ant species is their ability to dominate vast areas by forming dense networks of connected nests in contrast to the smaller and discrete, spatially dispersed colonies of most social insects. However, it was recently proposed that such supercolonies are more vulnerable to infection by parasites and diseases as they would serve as large targets with high rates of transmission from nests to nest. We studied the invasive garden ant Lasius neglectus, a pest species currently spreading throughout Europe. Several populations are infected with an ectoparasitic fungus, Laboulbenia formicarum, itself an introduced species, yielding a new host–parasite relationship. Long-term monitoring of the prevalence and intensity of infection in two populations (supercolonies) over 4–10 years revealed epizootic spread of the parasite with a 14 % annual increase in prevalence until ca. 80 % of all ants were infected. In contrast, no other local ant species with discrete colonies carried the parasite, although a local species (Lasius niger) proved susceptible in a cross-infection experiment. These results support the hypothesis that supercolonies potentially face an important challenge from parasites and diseases, with interesting perspectives for biological control of such ant species.

Short Title:Biol Invasions
Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith