Gonial chromosomes, their behaviour and metrical data in nine species of Fulgorids (Homoptera)

Abstract

A cytological study of nine fulgorid species revealed that they had similar get up of oogonial and spermatogonial chromosomes. Chromosomes were bean-shaped with a large pair while the remaining were gradually seriated. In the gonial complements one sex chromosome in males and two in females showed no differ-ential behaviour compared to the autosomes. The diploid number in female and male gonial complements was 20 and 19 respectively in Oliarus hodgarti; 26 and 25 in Barunoides albosignata; 28 and 27 in Diostrombus carnosus, Pyrilla pusana, Ricania zebra, Eoeurysa flavocapitata; 30 and 29 in Dictyophara pallida, Elasmocelis platypoda, Varma distanti. The behaviour of spermatocyte chromosomes in all the above species was of orthodox nature with the single X chromosome showing heteropycnotic behaviour in prophase I. The first division was reductional and the second equational. The chiasma frequency was generally one per bivalent except the large bivalent which sometimes had two. Relative percentage volume of the chromosomes was deter-mined from metaphase I. Results obtained in this investigation have been correlat-ed with the published data and the probable mode of evolution in the group has been discussed.