Caste allocation in litter Pheidole: lessons from plant defense theory

Michael Kaspari, Margaret M. Byrne

Research output: Contribution to journalArticle

46 Scopus citations

Abstract

The allocation to growth, defense and reproduction varies in social insects within a species' life cycle and between species. A life cycle model (Oster and Wilson 1978) generally failed to predict caste allocation in small litter-nesting colonies of Neotropical Pheidole. Two of its assumptions were often invalid: food was unlikely to be limiting in four of five populations, and sexual biomass production accelerated, not decelerated, with colony size in three of five populations. One of five Pheidole populations studied had higher caste ratios (soldiers /workers) in reproductive colonies as predicted, and in no species did caste functions conform to predictions. We also adapted three models from plant defense theory to study between-species patterns of caste allocation. Among 12 litter Pheidole the amount of sterile biomass devoted to soldiers varied from 18 to 62%. Queen size, growth rate, and soldier investment positively covaried. Only one model, the cost of replacement hypothesis (McKey 1979), correctly predicted that species with costly female alates invest more in defense. The two hypotheses linking apparency to defense may also be valid if fast-growing colonies are more likely to attract the attention of predators.

Original languageEnglish (US)
Pages (from-to)255-263
Number of pages9
JournalBehavioral Ecology and Sociobiology
Volume37
Issue number4
DOIs
StatePublished - Oct 1 1995

    Fingerprint

Keywords

  • Ant
  • Caste
  • Defense
  • Life history
  • Pheidole

ASJC Scopus subject areas

  • Behavioral Neuroscience
  • Ecology
  • Animal Science and Zoology
  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this