The ovaries of the investigated homopterans are telotrophicmeroistic and consist of several (7-21 ) ovarioles. Each ovariole is composed of three elements: an anteriorly localized terminal filament, a tropharium, and a posterior vitellarium. The latter comprises several developing ovarian follicles in a linear arrangement. The terminal filaments are relatively solid and composed of two distinct types of cells: the apical cells (ApCs) and the basal cells (BaCs). The BaCs are disc-shaped and oriented perpendicularly to the long axis of the ovariole, whereas the ApCs are strongly elongated and arranged parallel to this axis. The distribution of cytoskeletal elements has been studied with the use of electron microscope and histochemical methods. We show that the ApCs house prominent bundles of highly ordered microfilaments and/or parallel arranged microtubules. In contrast, BaCs contain only individual microtubules that are predominantly located in peripheral regions of the cells. It is suggested that microfilaments and microtubules present in the ApCs are responsible for the mechanical rigidity of the terminal filaments.