| Abstract: | Abstract In the females of Dendrolimus pini the pheromone-producing epithelium is present ventrally between the 8th and 9th abdominal segments. The epithelium is about 40 μm thick. The cells possess extensive microvillar borders, both apically towards the cuticle and laterally, towards the adjoining cells. In the spaces between the cells in the upper half of the epithelium there are loosely arranged cuticular lamellae adjacent to the microvillous borders. The epithelial cells have large, basally situated nuclei, whereas the apical parts have extensive arrangements of tightly packed and orderly arranged smooth endoplasmic reticulum. Clear vesicles and microbod–ies are present in the cytoplasm. The gland has a structural potential for high pheromone-producing capacity (the well-developed endoplasmic reticulum) as well as an effective emission apparatus (the microvillous borders/cuticular lamellae). These two elements could facilitate a pulsed pheromone emission that is effective in arousing the sensory system of males. |
