Inconspicuous matured males of worker form are produced in orphaned colonies of Reticulitermes speratus (Isoptera: Rhinotermitidae) and participate in reproduction

Differentiation of neotenics is easily induced by orphaning the worker termites of Reticulitermes speratus (Kolbe). Although it has previously been reported that the sex ratio of neotenics is female-biased, the background of this phenomenon and the gonad developmental process of workers in artificially orphaned colonies are unknown. Although both male and female conspicuous neotenics can emerge as a response to the orphaning of the colony, we observed that majority of the reproductive males that are formed do not molt into the neotenic morph and are therefore inconspicuous in the population. Participation of the inconspicuous reproductive males in sexual reproduction was confirmed by genetic analysis. Slight pigmentation of the abdominal sternites is the only characteristic of the inconspicuous reproductive males that enables them to be distinguished from normal male workers. The presence of the female ergatoid (one type of female neotenic) did not induce the production of inconspicuous reproductive males during the 12-week experiment time.