The larval stages of the variegated mud-loving beetle Heterocerus similis Grouvelle (Coleoptera: Heteroceridae)

Last instar larvae of the variegated mud-loving beetle Heterocerus similis Grouvelle are described and illustrated in detail. Comparative notes with earlier instars are also included. Based on the width of the head capsule and the prothorax four different instars were identified; considering that heterocerids show five larval instars, the four instars identified probably correspond to the last four. Larval length was not useful to recognize among different larval stages. The larva of H. similis is compared to that of H. freudei (Pacheco), the only other described South American heterocerid larva.