Worker longevity in the fire ant Solenopsis invicta: Ergonomic considerations of correlations between temperature, size and metabolic rates
Abstract
We compared long-term economic costs of producing and maintaining different size fire ant workers ( Solenopsis invicta) at two temperatures (24 and 30°C). Energetic costs for three sizes of workers were calculated from their biomass, longevity, respiration rates, and the energy content of worker tissue. Large workers lived considerably longer than small workers (50–140%, depending on temperature) and respired more slowly per mg of tissue (40%, independent of temperature). Overall, large workers cost about 30% less in cal/mo x mg than equal weights of small workers. However, on an individual basis, large workers were still four times more expensive than small workers because of a 6-fold weight difference. These data indicate that one large worker must provide services equivalent to at least four small workers, to justify the colony's energy investment.
- Publication:
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Journal of Insect Physiology
- Pub Date:
- January 1989
- DOI:
- 10.1016/0022-1910(89)90127-3
- Bibcode:
- 1989JInsP..35..643C
- Keywords:
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- Solenopsis invicta;
- ergonomic;
- caste;
- longevity;
- metabolic potential;
- respiration;
- division of labour