No abstract

The sex-pheromone-producing gland of Choristoneura fumiferana, as in other moths, is a modified intersegmental membrane between the eighth and ninth abdominal segments. Gland cells differ from epidermal cells in unmodified intersegmental membranes in their size, shape, and structure. One to 2 days before emergence of the adult, the gland cells have few microvilli and the cytoplasm contains mainly rough endoplasmic reticulum. By 1 h before emergence, the cells have the adult characteristics. The basal region below the nucleus contains Golgi complexes, lipid droplets, glycogen deposits, and rough endoplasmic reticulum. The apical region contains many microbodies and extensive smooth tubular endoplasmic reticulum. The apical surface has numerous well-developed microvilli, each of which contains a core of smooth endoplasmic reticulum. In contrast to gland cells, unmodified epidermal cells only contain rough endoplasmic reticulum and their apical projections are small and ill-defined. Cuticle of the gland and unmodified intersegmental membrane does not change after deposition but continues to resemble that of the developing gland 1 to 2 days before emergence. Pore canals are present as gaps in the endocuticle and follow the helicoidal arrangement of the microfibrils. Near the microvilli the pore canals contain a filamentous structure which is replaced by epicuticular filaments near the first lamella of the endocuticle. Groups of epicuticular filaments terminate at an oval depression in the dense epicuticle. Each oval depression opens at the surface of the inner cuticulin. Epicuticular filaments are not the immediate precursors of the pheromone. The probable role of the epicuticular filaments in pheromone synthesis and release is discussed.

The defensive secretion of a millipede, Uroblaniulus canadensis (Say), is shown to consist of a mixture of benzoquinones and aliphatic compounds. Two of the benzoquinones are identified as p-benzoquinone and 2,3-dimethoxybenzoquinone. The gross structure of the gland producing the secretion is described and histological studies reveal the presence of secretory units. Each secretory unit consists of a pair of specialized cells and has a tubule to transport the secretion manufactured in these cells to a large cuticular-lined reservoir.

No abstract

Field studies have shown that cis-11-tetradecenal is an effective attractant for male Choristoneura conflictana, a pest of aspen. These studies also indicate that cis-11-tetradecenal is probably a secondary component in the sex pheromone systems of Choristoneura rosaceana and Choristoneura fumiferana.