• Megoura viciae;
  • Aphis fabae;
  • juvenile hormone III;
  • aphid polymorphism;
  • homopteran/hemipteran JHs;
  • GC-MS

ABSTRACT. Whole body extractions from larval and adult apterous forms of Megoura viciae, and from adult Aphis fabae, were analysed for the known insect juvenile hormones (JHs) by a gas chromatography-mass spectrometric method. Low levels of JH III were detected in both aphid species, the first identification of a juvenile hormone from an homopteran insect. Although the mean titre in adult M. viciae is higher in long-day than in short-day reared insects (0.12±0.03 v. 0.04±0.01 ng/g), titres were variable and measurements overlapped. The results are discussed in the context of the hormonal control of aphid polymorphism and the question of identity of homopteran and hemipteran JH.