Ultramorphology of the third instar larvae of Miridiba trichophora (Coleoptera: Melolonthinae: Rhizotrogini)

Abstract

Rhizotrogini are one of the most typical phytophagous scarab beetles, named primarily for their larvae attacking plant roots. Miridiba trichophora is the most widely distributed species of its genus. Its larvae are the main harmful stage and the primary target for control efforts. However, identifying M. trichophora larvae in the field is difficult due to the serious lag in larval classification work. In this study, the larvae of M. trichophora were obtained through rearing and observed using light and scanning electron microscopy. The larvae of M. trichophora are peculiar for the labrum possessing two curved horizonal ridges, the epipharynx equipped with 14 heli and a proplegmatium, the raster furnished with numerous prominent setae pointing the inconspicuous palidia, and the spiracles on the seven- and eighth abdominal segments being comparative larger than the other abdominal spiracles.