Numerical and biomass caste proportions in colonies of the termitesNasutitermes corniger andN. ephratae (Isoptera; Termitidae)

Abstract

Caste ratios among monogynousN. corniger colonies are less variable (higher correlation coefficients and lower variances) than among polygynous colonies. Polygynous colony caste proportions are more constant than for queenless colonies. Correlation coefficients are not significantly different between numerical and biomass neuter caste ratios (large workers: small workers; total worker population: soldiers) inN. corniger orN. ephratae. The intraspecific range of both numerical and biomass percentages of soldiers, small workers, and large workers is large inN. corniger andN. ephratae. Numerical and biomass percentage of soldiers, small workers, and large workers were all significantly different between monogynousN. corniger and monogynousN. ephratae colonies. Mean individual weights of soldiers, large workers, and small workers did not differ between species. Single queenN. corniger colonies tend to have a higher ratio of the number of small workers: large workers and the number of soldiers: workers, and a lower proportion of presoldiers: soldiers than do monogynousN. ephratae nest. PolygynousN. corniger colonies have a statistically larger ratio of number of larvae: number of workers, and a higher number of presoldiers: soldiers than do single queen colonies. These all suggest differences in growth rate related to single versus multiple queens. Monogynous and polygynous nests have significantly higher ratios of larvae: workers than do queenless colonies. In both numerical and biomass analyses of variousN. corniger caste ratios, correlation coefficients were highest in comparisons between the total number or dry weight of all workers vs soldiers. Mean individual dry weights of large and small workers in queenlessN. corniger colonies are significantly higher than in queenright colonies. This may be because the queenless colony population is aging without generating more young so fewer individuals are in the early worker instars.