Morphology of the male reproductive system, sperm ultrastructure and γ-irradiation of the red palm weevil Rhynchophorus ferrugineus Oliv. (Coleoptera: Dryophthoridae)

• The genital apparatus of the Rhynchophorus ferrugineus male was studied.
• The morphology of the accessory glands was reported.
• The ultrastructure of the germ cells during all the spermatogenetic process was investigated.
• A preliminary ultrastructural comparison between non-irradiated and irradiated sperm was carried out.

In the present study we describe the morphology of the male reproductive apparatus and sperm ultrastructure of the red palm weevil – an invasive pest of several palm tree species – as well as the most important steps of spermatogenesis. The reproductive apparatus consists of a pair of testes (each formed by two lobes) a long tube-like accessory gland, a prostate gland and a small accessory gland. Characteristic features of the sperm are 90–100 μm total length, 10 μm nucleus, two mitochondrial derivatives, two accessory bodies, one well-developed puff-like structure and a typical insect 9+9+2 flagellar axoneme. One of the methods used for the biological control of pests is the Sterile Insect Technique (SIT), for the evaluation of which we make a preliminary comparison of the sperm ultrastructure of non-irradiated and irradiated weevils (at a dose of 80 Gray).