The influence of host size on sex ratios in the parasitoid Diglyphus begini (Hymenoptera: Eulophidae) Academic Article uri icon


  • Abstract. 1. Sex ratio in the ectoparasitoid, Diglyphus begini (Ashmead), attacking larvae of the dipterous leafminer Liriomyza trifolii (Burgess) in glasshouse marigolds, is best depicted by a model where sex ratio varies as a function of host size. 2. Male D. begini progeny are produced in hosts significantly smaller in size than those producing female progeny. 3. Female wasps attack and oviposit on the largest leafminer larvae available and whether a host is large or small depends upon the size of the other hosts attacked. 4. Diglyphus begini females adjust the thre:shold size for the changeover in sex allocation relative to the size of hosts attacked; however, the sex ratio is maintained at between 60% and 70% males. 5. The patterns observed in these glasshouse studies are not due to sexspecific differential mortality or superparasitism. Copyright 1990, Wiley Blackwell. All rights reserved

published proceedings

  • Ecological Entomology

author list (cited authors)

  • HEINZ, K. M., & PARRELLA, M. P.

citation count

  • 26

complete list of authors


publication date

  • November 1990