Size and heterozygosity influence partner selection in the Formosan subterranean termite

Abstract

In monogamous species that exhibit extensive biparental investment, such as termites, both sexes are predicted to be selective when choosing a mate. Size-related traits are expected to be important in partner selection because the fat reserves of the colony founders sustain the incipient colony. Partner relatedness and heterozygosity determine the degree of inbreeding and genetic diversity within the colony and may thus also influence partner selection. To test these predictions, we investigated whether phenotypic and genetic traits influence mate choice and/or competitive advantage during pair formation of Formosan subterranean termites, Coptotermes formosanus (Isoptera: Rhinotermitidae). Pair formation in termites normally occurs within a short period after swarming when alates form tandem pairs on the ground. Alates were collected from 5 light trap samples in the French Quarter of New Orleans, LA. From each sample, both tandem pairs and single individuals were collected and their sex, body weights, and head widths were recorded. Pairwise relatedness and individual levels of heterozygosity were determined by microsatellite genotyping. Males in tandem pairs with females had a significantly larger head width than males that did not form tandem pairs. Weights as well as head widths of tandem running partners were positively correlated. For the majority of the samples, relatedness between tandem partners did not differ from the relatedness to members of the other tandem pairs. Thus, no kin discrimination occurred during tandem running. However, females engaged in tandem running had a higher degree of heterozygosity than females that remained single. These findings suggest partner selection and/or competitive advantage based on size-related phenotypic parameters and genetic diversity. The pairing advantage of heterozygous females might explain previous findings of sex-biased alate production depending on the degree of inbreeding in colonies of several species of the genus Coptotermes.

Pairing patterns in relation to body size, genetic similarity and multilocus heterozygosity in a tropical monogamous bird species

“…Limited information exists on the influence of heterozygosity on pairing status in monogamous species. However, paired females were found to be more heterozygous than single females in the Formosan subterranean termite (Coptotermes formosanus), while there was no difference in heterozygosity between paired and single males (Husseneder and Simms 2008). The weak effect observed in the present study might be due to a relatively small sample size for unpaired females (n=16).…”

“…We first used GLMs to analyze the relationship between wing chord and tarsus length, as well as the relationship between each morphometric variable and MLH, using each time sex as covariate (Husseneder and Simms 2008;Shaner et al 2013). We then used logistic regressions to test for the effects of tarsus length, wing chord and MLH, and those of all the interactions between these three variables, on social status (coded as a binomial variable, i.e.…”

Communication and Social Regulation in Termites

“…Indeed, more and more experimental evidence suggests that the pairing of males and females is controlled rather than random and mates are chosen based on numerous criteria, such as partner relatedness (Shellman-Reeve 2001), size and body mass (Shellman-Reeve 1999; , and level of heterozygosity (Husseneder and Simms 2008).…”

Semiochemical compounds of preen secretion reflect genetic make-up in a seabird species

“…Although most studies have focused on morphological and behavioural traits [1], evidence is accruing for multiple genetic criteria for mate choice [2,3]. Females may choose males with 'good genes', such as those with alleles or allele combinations increasing fitness [4,5] or with high heterozygosity [6][7][8].…”