Neotenic Phenotype and Sex Ratios Provide Insight into Developmental Pathways in Reticulitermes flavipes (Isoptera: Rhinotermitidae)
One hundred and three laboratory colonies of the eastern subterranean termite. Reticulitennes jlavipes (Kollar). ranging from 4 100 to 9 yr of age, were destructively sampled, and the numbers of eggs and other life stages were counted. Polygyny was maintained in 9.7% (n = 31) of the groups censused at four months, whereas monogyny was the only condition found thereafter. Polyandry was recorded in 17% of colonies sampled over a 2-yr period. Colonies set up with multiple males/ females achieved similar rates of progeny (numbers, caste proportions, and biomass) compared with colonies initiated by a single royal pair. The soldier caste was present at the 4-mo census, whereas nymphs and neotenics first occurred in 2-yr-old groups. Primary queens reached a mean body mass of 7.06 mg (SD 2.4) after 2 yr and did not gain considerable weight between 2 and 4 yr. Two 6-yr-old queens weighed 17 and 18 mg, respectively, and produced the highest number ofeggs per day. Asimple computer model of colony growth, using both egg-laying rates obtained from our census and hypo thetical egg-laying rates, revealed that the expected number oflarvae matched the numbers censused in colonies up to 2 yr of age, although worker numbers were consistently overestimated. The data indicate that a monogyne colony of R. j/£/.vipes could not attain the population size occasionally described in field studies. Extrapolating laboratory data and potential reproductive mechanisms that can account for field data are discussed.