Costs and benefits of joint colony founding in Australian Acacia thrips

Abstract

Facultative joint colony founding by social insects (pleometrosis) provides an outstanding opportunity to analyze the costs and benefits of sociality. Pleometrosis has been documented for a range of social insects, but most studies on the adaptive benefits of this behavior are restricted to the Hymenoptera. In this study, we provide the first analysis of costs and benefits associated with pleometrosis for Australian Dunatothrips, which form domiciles by glueing together phyllodes (leaves) of their Acacia host plant. In Dunatothrips aneurae, the distribution of foundress numbers per nest indicated that females formed associations non-randomly. Furthermore, average group size was independent of both the number of foundresses on the host plant and the number of mature colonies, suggesting that this behavior was not simply a response to limited availability of nesting sites. Although per capita reproduction declined with increasing group size, we also identified two benefits of pleometrosis: (1) individual foundresses in groups had higher survival than solitary foundresses during the brood development period, and (2) larger colony sizes resulting from pleometrosis provided a benefit later in colony development, because a higher proportion of D. aneurae adults survived invasions by the kleptoparasite Xaniothrips mulga when colony size was larger. These results demonstrate that the reproductive costs of pleometrosis are at least partially counterbalanced by survival benefits.

Influence of queen phenotype, investment and maternity apportionment on the outcome of fights in cooperative foundations of the ant Lasius niger

“…Joint nesting also increases colony fitness in other contexts, for example (5) by improving resistance to adverse abiotic conditions (temperature, precipitation;Tschinkel & Howard 1983;Pfennig 1995;Helms Cahan 2001), (6) by reducing costs associated with nest construction and maintenance (Pfennig 1995;Helms Cahan 2001) or (7) by allowing production of reproductives at an earlier stage (Vargo 1988). Similar benefits have been proposed to account for the evolution of cooperative foundations in other social insects, including termites (Thorne 1982), wasps (Strassmann et al 1988;Tibbetts & Reeve 2003), bees (Soucy et al 2003) and thrips (Morris et al 2002;Bono & Crespi 2006).…”

Maternal effects in cooperative breeders: from hymenopterans to humans

“…Helper effects refer to the effect of helper number on the reproductive output of the group: NR, no relationship; LR, linear; QR, quadratic; AR, accelerating relationship. (Sources : Wilson 1971;Taborsky 1984Taborsky , 1994Stacey & Koenig 1990;Duffy 1996;Crespi & Mound 1997;Solomon & French 1997;Stern & Foster 1997;Avilés & Tufiñ o 1998;Bourke 1999;Duffy & Macdonald 1999;Hatchwell 1999;Russell 2004;Dierkes et al 2005;Heg et al 2005;Kranz 2005;Whitehouse & Lubin 2005;Bono & Crespi 2006;Lubin & Bilde 2007;Salomon & Lubin 2007;Korb 2008 in each is the fact that substantial variation exists within the same mother over time, among mothers within a population and between species (table 1). First, in the majority of species, cooperative groups consist of primary reproductive(s) and their offspring, which have foregone dispersal (Emlen 1995;Bourke 1997;Choe & Crespi 1997;Thorne 1997).…”

“…First, in the majority of species, cooperative groups consist of primary reproductive(s) and their offspring, which have foregone dispersal (Emlen 1995;Bourke 1997;Choe & Crespi 1997;Thorne 1997). However, the genetic structure of groups varies owing to immigration, co-breeding, breeder replacement, extra-group mating and /or group amalgamation (Stern & Foster 1997;Bourke 1999;Cockburn 2004;Russell 2004;Dierkes et al 2005;Whitehouse & Lubin 2005;Bono & Crespi 2006;Ratnieks et al 2006;Korb 2008). Second, to varying degrees, helpers/workers can be associated with a reduction in maternal contributions to offspring care, an increase in maternal productivity within seasons and survival between seasons, and/or an increase in the condition, survival and future reproductive capacity of offspring (Wilson 1971;Bourke 1997;Choe & Crespi 1997;Keller & Genoud 1997;Thorne 1997;Dickinson & Hatchwell 2004;Russell 2004;Russell et al 2007a;Salomon & Lubin 2007).…”

Geographic patterns in the distribution of social systems in terrestrial arthropods

“…Individuals may establish nests in small groups or remain in groups with multiple queens for an extended period of time in harsher environments, or in places where solitary founders are extremely unlikely to succeed (e.g. Ross & Visscher, 1983; Pfennig, 1995; Choe & Perlman, 1997; Rissing, Johnson & Martin, 2000; Matsuura & Nishida, 2001; Sanetra & Crozier, 2002; Dunn & Richards, 2003; Bono & Crespi, 2006; Heinze, 2008). However, individuals living in more clement environments exhibit more solitary nest founding.…”