Variation in the level of aggression, chemical and genetic distance among three supercolonies of the Argentine ant in Europe

Abstract

In their invasive ranges, Argentine ant populations often form one geographically vast supercolony, genetically and chemically uniform within which there is no intraspecific aggression. Here we present regional patterns of intraspecific aggression, cuticular hydrocarbons (CHCs) and population genetics of 18 nesting sites across Corsica and the French mainland. Aggression tests confirm the presence of a third European supercolony, the Corsican supercolony, which exhibits moderate to high levels of aggression, depending on nesting sites, with the Main supercolony, and invariably high levels of aggression with the Catalonian supercolony. The chemical analyses corroborated the behavioural data, with workers of the Corsican supercolony showing moderate differences in CHCs compared to workers of the European Main supercolony and strong differences compared to workers of the Catalonian supercolony. Interestingly, there were also clear genetic differences between workers of the Catalonian supercolony and the two other supercolonies at both nuclear and mitochondrial markers, but only very weak genetic differentiation between nesting sites of the Corsican and Main supercolonies (F(ST) = 0.06). A detailed comparison of the genetic composition of supercolonies also revealed that, if one of the last two supercolonies derived from the other, it is the Main supercolony that derived from the Corsican supercolony rather than the reverse. Overall, these findings highlight the importance of conducting more qualitative and quantitative analyses of the level of aggression between supercolonies, which has to be correlated with genetic and chemical data.

Relationship between invasion success and colony breeding structure in a subterranean termite

“…; Blight et al . ). The homogenization of chemical recognition cues (cuticle hydrocarbons) associated with unicoloniality in introduced populations has often been attributed to a reduction in genetic diversity induced by founding events (bottlenecks) (Tsutsui et al .…”

“…; Blight et al . ). Interestingly, the introduction of social insects is often accompanied by important modifications of their breeding structure (i.e.…”

At the brink of supercoloniality: genetic, behavioral, and chemical assessments of population structure of the desert ant Cataglyphis niger

“…Polydomy and supercoloniality can be detected genetically as well as behaviorally and chemically. Members of a supercolony are tolerant to each other even if they originate from different nests at the time of their testing, and exhibit chemical uniformity of cuticular hydrocarbon compositions (Errard et al, 2005;Brandt et al, 2009b;Vonshak et al, 2009;Blight et al, 2012;Kidokoro-Kobayashi et al, 2012). Therefore, assessing the population structure of an ant species is best done by encompassing all three parameters, genetic, behavior and recognition chemistry.…”

“…Unicoloniality is also typified by the lack of aggression, even between very distant nests e.g., Linepithema humilis (Giraud et al, 2002;Brandt et al, 2009b;Blight et al, 2012), Wasmannia auropunctata (Errard et al, 2005;Vonshak et al, 2009;Foucaud et al, 2010) or Pheidole megacephala (Fournier et al, 2009). This is attributed to the relaxation or complete loss of nestmate recognition in these population, the mechanism of which is postulated to be either "genetic cleansing" following introduction (Giraud et al, 2002) or a "bottleneck" phenomenon (Suarez et al, 2008).…”

Colony Breeding Structure of the Invasive Termite <I>Reticulitermes urbis</I> (Isoptera: Rhinotermitidae)

“…Introduced populations of the bumblebee, Bombus terrestris, have large colonies with two reproducing generations per year, whereas native populations have small colonies with only one reproducing generation per year (Buttermore 1997, Nagamitsu andYamagishi 2009). Introduced populations of several taxa of ants have a unicolonial social organization, including the most destructive invasive species such as Anoplolepis gracilipes, Linepithema humile, Pheidole megacephala, and Wasmannia auropunctata (Morel et al 1990, Vanloon et al 1990, Holway et al 2002, Tsutsui and Suarez 2003, Le Breton et al 2004, Fournier et al 2009, Blight et al 2012. Unicolonial populations are characterized by the absence of colony boundaries between nests that contain many queens and interchange individuals and brood (Hö lldobler and Wilson 1990).…”