Abstract: The study reveals that four species (M. matsumurae, M.massonianae, M. koraiensis, M. dahuriensis) have obvious difference in their ultrastructure of sperms.The main difference appeared in the quantity of microtubules, their arrangging patterns and the angle of the microtubular row has been discovered.The key to four species is as follows:1.The microtubules are arranged in whorled radii patterns in the non-nuclear region……2The microtubules are arranged in spirale patterns in the non-nuclear region……32.The angle of microtubules row in non-nuclear region is 170°—190°……M. massonianaeThe angle of microtubules row in non-nuclear region is 30°—50°……M. koraiensis3. In the nuclear region, the microtubules are arranged in whorled radii patterns, the angle of microtubular row is 40°—60°……M. matsumuraeIn the nuclear region, the microtubules are arranged in whorled radii patterns, the angle of microtubular row is 90°—160°……M. dahuriensis

Key words: Pine scale insect, Sperm, Ultrastructure