OVARIAN DEVELOPMENT IN HABROBRACON JUGLANDIS (ASHMEAD) (HYMENOPTERA: BRACONIDAE). I. THE ORIGIN AND DIFFERENTIATION OF THE OOCYTENURSE CELL COMPLEX

¹ Department of Biology, University of Notre Dame, Notre Dame, Indiana 46556 and Department of Biological Sciences, Northwestern University Evanston, Illinois 60201

Normal oogenesis in the adult wasp, Habrobracon juglandis, is described. Accounts are given of: (1) the mitotic behavior of oogonia and cystocytes: (2) the production of synaptonemal complexes by pro-oocytes in the germarium; (3) the formation of an egg chamber and its movement through the vitellarium; (4) the ultrastructural details of the transfer of cytoplasmic organelles to the oocyte by the nurse cells; and (5) the production of accessory muclei and protein yolk spheres in the ooplasm. Comparisons are drawn between Habrobracon and other insects with respect to: (1) the cystocyte divisions, the origin of ring canals, and the control of pro-oocyte differentiation; (2) the possible symbiotic relationships of bacteria which reside in ovarian tissue; (3) the proposed functions performed by accessory nuclei and protein yolk spheres; and (4) the synthesis of rRNA by the nurse cells.