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).