Cytological investigations of parthenogenesis in gall wasps (Cynipidae,Hymenoptera)

The chromosome number was determined in eleven heterogonous species of gall-wasps on caks and in four species which reproduce by constant parthenogenesis on wild roses. One of the latter group proved to be a natural triploid. Maturation was studied in representative forms from synapsis through diakinesis and the abortive first division to the second division in the laid egg. Chromosome regulation in the developing egg, the production of parthenogones of different sex and the role of the sperm are discussed briefly.