Intra-specific variation in strategic ejaculation according to level of polyandry in Callosobruchus chinensis

Takashi Yamane, Takahisa Miyatake

Research output: Contribution to journalArticle

22 Citations (Scopus)


Optimal sperm allocation should differ according to the level of polyandry within a population, because the risk of sperm competition depends on the remating frequency of females. We compared the number of sperm ejaculated by males into the female reproductive organ between strains with different levels of polyandry in the adzuki bean beetle, Callosobruchus chinensis (Coleoptera: Bruchidae) when males were reared in different larval densities in a bean. The results showed that males derived from a population with a higher level of polyandry increased ejaculatory expenditure when they were reared under higher larval densities. We discuss the evolutionary correlation of ejaculatory expenditure to the level of polyandry.

Original languageEnglish
Pages (from-to)1240-1243
Number of pages4
JournalJournal of Insect Physiology
Issue number11
Publication statusPublished - Nov 1 2005



  • Adzuki bean beetle
  • Differential allocation
  • Ejaculatory expenditure
  • Larval density
  • Sperm competition

ASJC Scopus subject areas

  • Physiology
  • Insect Science

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