Fighting Behavior of Male Golofa Porteri Beetles (Scarabeidae:Dynastinae)

Large males of Golofa porteri possess several striking secondary sexual characteristics: the head has a long, curving horn with serrations along its edges; the prothorax has an even longer, thinner, nearly vertical horn which is smooth and covered on its anterior surface with a thick mat of golden hairs; and the front legs, especially the robust tibiae and tarsi, are monstrously elongate, with the last tarsomeres sporting thick growths of golden hair on their ventral surfaces. Howden and Campbell (1974) observed two struggles between males in nature at apparent feeding sites on long thin stalks of a bamboo-like plant. Wille (1943) also noted G. aegeon (especially males) on sugar cane stalks. This study is a follow-up of these observations to determine the functions of the males’ bizarre secondary sexual structures.