Colony Social Organization and Population Genetic Structure of an Introduced Population of Formosan Subterranean Termite from New Orleans, Louisiana

Abstract

The Formosan subterranean termite, Coptotermes formosanus Shiraki, is an invasive species in many parts of the world, including the U.S. mainland. The reasons for its invasive success may have to do with the flexible social and spatial organization of colonies. We investigated the population and breeding structure of 14 C. formosanus colonies in Louis Armstrong Park, New Orleans, LA. This population has been the focus of extensive study for many years, providing the opportunity to relate aspects of colony breeding structure to previous findings on colony characteristics such as body weight and number of workers, wood consumption, and intercolony aggression. Eight colonies were headed by a single pair of outbred reproductives (simple families), whereas six colonies were headed by low numbers of multiple kings and/or queens that were likely the neotenic descendants of the original colony (extended families). Within the foraging area of one large extended family colony, we found genetic differentiation among different collection sites, suggesting the presence of separate reproductive centers. No significant difference between simple family colonies and extended family colonies was found in worker body weight, soldier body weight, foraging area, population size, or wood consumption. However, level of inbreeding within colonies was negatively correlated with worker body weight and positively correlated with wood consumption. Also, genetic distance between colonies was positively correlated with aggression levels, suggesting a genetic basis to nestmate discrimination cues in this termite population. No obvious trait associated with colony reproductive structure was found that could account for the invasion success of this species.

Define Colony Number of Subterranean Termites Coptotermes gestroi(Isoptera: Rhinotermitidae) in Selected Infested Structures

“…Furthermore, it is possible that the age of termite colonies might be the reason of finding larger or smaller colonies in some places than others. Maybe, the smaller colonies are newly established colonies, while the larger ones have been in the area for a long time (Husseneder 2005;Vasconcellos et al 2010).…”

Genetic diversity and colony breeding structure in native and introduced ranges of the Formosan subterranean termite, Coptotermes formosanus

“…1). Additional population genetic analyses were performed on previously published data (populations from Japan, the continental USA, Hawaii and China, Vargo et al 2003Husseneder et al 2005Husseneder et al , 2008 and were included in this study for comparison.…”

“…At least 20 individuals from each sample were scored at eight microsatellite loci (Cf4:1A2-4, Cf4-4, Cf4-9A, Cf4-10, Cf8-4, Cf10-4, Cf10-5, Cf12-4, Vargo and Henderson 2000), which are routinely used for population genetic analyses of C. formosanus (e.g., Vargo et al 2003;Husseneder et al 2005) and did not show null alleles or linkage disequilibrium. A detailed description of the polymerase chain reaction and genotype scoring procedures can be found in Vargo (2000).…”

“…The large foraging areas of some Formosan subterranean termite colonies extend to over 1,600 m 2 Husseneder et al 2005), and may be comparable to supercolonies in ants. Like invasive ants, populations of some invasive termite species, e.g., Reticuliterme flavipes and R. urbis have reduced genetic diversity and large colonies with exclusively extended family structures in the introduced range (Western Europe) (Dronnet et al 2005;Leniaud et al 2009Leniaud et al , 2010.…”

“…We compare the results of this study to reanalyzed data from previously published C. formosanus populations from China, Japan, Oahu (HI) and the US mainland (Vargo 2003;Husseneder et al 2005Husseneder et al , 2008 to identify potential factors that may facilitate invasiveness and identify possible routes of invasion and subsequent spread. Specifically we (1) describe the population genetic structure and relationships among native and introduced populations of C. formosanus, (2) test whether C. formosanus populations in the introduced range experienced genetic bottlenecks leading to reduced genetic diversity, and (3) compare the colony breeding structure among native and introduced C. formosanus populations to test the hypothesis that introduced populations predominantly consist of extended family colonies (in analogy to the large polygynous supercolonies found in some invasive ants and Reticulitermes species).…”