Multiple male and female reproductive strategies and the presence of a polyandric mating system in the termite Reticulitermes labralis (Isoptera:Rhinotermitidae)

Abstract

IntroductionHigh fertility of the reproductive caste is essential for maintaining and expanding a termite colony. The most important factors for fertility of termites are thought to be the number of individuals in the reproductive caste and the copulatory selectivity of individuals in the breeding system. Life history and reproductive strategy often differ from one species to another (Lainé & Wright, 2003). The diverse and flexible breeding systems found in lower termites pre-adapt them to invade new environments or marginal habitats (Dronnet et al., 2005). Therefore, the study of the mating systems of termites has important significance to understand colony dispersal and establishment.In general, termite colonies are founded by a single primary king and a single primary queen that pair during nuptial flights, mate and subsequently produce the other colony members (Thorne et al., 1999). Since the reproductive system of termite is usually monogamous, the fecundity of the colony is AbstractReproductive systems of termite colonies may involve the number of individuals in the reproductive caste and the copulatory selectivity of reproductive individuals (i.e., polyandry or polygamy), both of them impacting directly the fertility and genetic diversity of the colony. Polygamy is widespread in the lower termites, whereas polyandry appears to be mostly absent in termites. In this paper, the differentiation of male and female neotenics was observed in orphaned experimental colonies of the subterranean termite Reticulitermes labralis. The artificial orphaned colonies began to produce neotenics only a week after colony establishing, with more neotenics appearing in the same group as time went by. Finally, each experimental group reserved multi-neotenics consisting of male and female neotenic individuals. Our results demonstrated that these neotenic individuals retained in the colony participated in reproduction. A genetic analysis at four microsatellite loci showed that in addition to the conspicuous morphologically male reproductives, there were inconspicuous males or workers that had copulated with the females in the orphaned colony. Multiple male and female reproductive individuals existed together in a single colony, and one female neotenic could mate with several male reproductives in a short time. Thus, multiple male and female reproductive systems and a polyandric mating system are present in R. labralis.

Unrelated secondary reproductives in the neotropical termite Silvestritermes euamignathus (Isoptera: Termitidae)

“…This hypothesis unites the occurrence of pleometrotic colony foundation with a polyandry mating system by the co-founding females. Although this hypothesis seems to be the less probable because of the absence of known polyandry in primary reproductives in termites (Hartke and Baer 2011), a recent study by Wu et al (2013) found evidence of polyandry in neotenics in the termite Reticulitermes labralis. These authors showed that one female neotenic mated with at least two male neotenics, as the alleles present in the offspring did not correspond to either asexual reproduction or 29 71 140 248 464 518 587 590 A T T C T C T G T KU521793 B T…”

Interspecific Hybridization between the Two Sympatric Termite Reticulitermes Species under Laboratory Conditions

“…Alates living in dead logs were brought to the laboratory and kept under moisture 75% at a temperature of 25 • C to promote dispersal flight. Subsequently, individual alates were removed from dead logs and their genders were identified via the shape of the seventh abdominal sternite [12,13]. Individuals with the same sex from the same colony in each species were placed in Petri-dishes with a small piece of wood and a moistened filter paper for pairing experiments commencing of the day when nestmates in their home colony disperse.…”

“…DNA was extracted from each individual (detailed sample data see Table S2) using a TIANamp Genomic DNA Kit (Tian Gen biotech Co., Ltd., Beijing, China) according to the recommendations of the manufacturers. Each DNA sample was amplified by PCR and performed using five pairs of microsatellite primers: Rs03, Rs78, Rs76, Ra144 and Ra141 (Table S1) and the conditions for each PCR have been improved base on the research conducted by Wu et al [13]. A color marker was added to 5′-primers and all primers synthesized by Invitrogen Trading (Shanghai, China) Co., Ltd. GeneMapper v4.0 (Applied Biosystems, Foster City, CA, USA) and Peak Scanner v1.0 (Applied Biosystems, Foster City, CA, USA) were used for analysis.…”

The transition path from female workers to neotenic reproductives in the termite Reticulitermes labralis

“…In our previous study on R. labralis, a genetic analysis at four microsatellite loci showed that the male workers copulated with NRs and produced offspring even if there were male NRs in the colony (Wu, Su, Kong, Liu, & Xing, 2013). Although no male NRs emerged in the experimental colonies, the female NRs laid eggs, and then offspring hatched.…”

“…The female reproductives of R. labralis were not able to produce offspring by parthenogenesis. In our previous study on R. labralis, a genetic analysis at four microsatellite loci showed that the male workers copulated with NRs and produced offspring even if there were male NRs in the colony (Wu, Su, Kong, Liu, & Xing, 2013). Fujita and Watanabe (2010) also reported that in R. speratus, the male workers developed into inconspicuous reproductive males without undergoing a moult and without exhibiting any significant changes in morphology.…”