Caste determination in Bombus terrestris: Differences in development and rates of JH biosynthesis between queen and worker larvae

Jonathan Cnaani, David W. Borst, Z. Y. Huang, Gene E. Robinson, Abraham Hefetz

Research output: Contribution to journalArticlepeer-review

Abstract

To study the possible role of juvenile hormone in caste determination in Bombus terrestris, we measured development and rates of juvenile hormone biosynthesis in vitro in larvae destined to develop into either workers or queens. Larvae of both castes developed through four instars and had the same growth rates. However, the duration of the instars was longer for queen larvae, and their head width at the third and fourth instars was significantly larger. After validating the well-known radiochemical assay of JH for bumble bee larvae, we show that worker larvae corpora allata exhibited a constant and low rate of JH biosynthesis, never more than 5 pmol JH/h/pair. Queen larvae, in contrast, had two peaks of JH biosynthesis: a small one during the first instar, which has previously been correlated with caste determination; and a large peak, previously undetected, above 40 pmol JH/h/pair, during the second and third instars. We suggest that caste determination in this species is mediated by JH and that the duration of larval instars is a key factor. The possibility that the queen influences Caste determination via an effect on instar duration is also discussed.

Original languageEnglish (US)
Pages (from-to)373-381
Number of pages9
JournalJournal of insect physiology
Volume43
Issue number4
DOIs
StatePublished - Apr 1 1997

Keywords

  • Bombus terrestris
  • Caste determination JH
  • Larval development

ASJC Scopus subject areas

  • Physiology
  • Insect Science

Fingerprint Dive into the research topics of 'Caste determination in Bombus terrestris: Differences in development and rates of JH biosynthesis between queen and worker larvae'. Together they form a unique fingerprint.

Cite this