The Morphology and Functions of the Reproductive Systems of Dendroctonus monticolae Hopk. (Coleoptera: Scolytidae)

The male and female reproductive organs of the mountain pine beetle, Dendroctonus monticolae Hopk. are described, and interpretations given for functions of the parts on the basis of activity during mating, sperm transfer, egg formation and ovulation. Some morphological changes of the reproductive organs during the adult life cycle are also noted.Three pairs of accessory glands associated with spermatophore production are evident in the male beetle. One of these was previously termed the seminal vesicles. A complex musculature operates the male genital organ during copulation. The female organs have four telotrophic ovarioles with a posterior calyx region that has a possible secretory function. Evidence indicates that organs previously termed "colleterial glands" have a digestive and reabsorbing function. The bursa copulatrix may be more closely allied with the function of the accessory glands than with the mating process. Parts of the spermatheca have been more precisely defined according to function.