Formation of temporary flagellar structures during insect organogenesis.

Cilia and flagella are rare in nongerminal tissues of anthropods, and are generally thought to be restricted to sperm and sensory cells in insects (2). Whitten (5) has reported the presence of kinetosomes at the base of mitotrichia in the dipteran fly Sarcophaga bullata, but reports no evidence of the organization of fibrous elements characteristic of cilia and or flagella. During an ultrastructural analysis of morphogenesis of the colleterial gland of the silk moth Hyalophora cecropia, we found the first example of paired flagella associated with an insect secretory cell. These structures are also unusual in that they serve a temporary role in morphogenesis and subsequently disappear at the terminal stages of differentiation.