Oocyte Development in the Scavenger Beetle, Dermestes vulpinus(Klug.) (Dermestidae: Coleoptera).

Five stages of oocyte development in the adult scavenger beetle, Dermestes vulpinus were identified using histological technique. Stage 1 and 2 were represented by the differentiation of the oocyte, and the formation of the follicular envelope. Stage 3 and 4 were characterised by a considerable enlarg-ment of the oocyte which occurred due to an enormous deposition of yolk in the oocyte cytoplasm. The viteJline membrane and chrion were formed around the terminal oocyte of stage 5. Relatively, few studies have been carried out on egg development in acrotrophic ovarioles of the polyphagid Coleopteran (Schlottman and Bonhag 1958, Aggar-wal 1967, Sweeny et al. 1970, Gerber et al 1971, Biining 1972, Ullmann 1973, Klock and Matuszewski 1977, Billinski and Petryszaki 1978, and Al-Khalifa 1981). However, nothing has been published on oocyte development of Der¬mestes maculatus (Klug). The present investigation was undertaken to identify oocyte developmental stages and to attempt to correlate changes in the growth characteristics of the oocyte with histological events in the follicular cell layer of D. maculatus