Larval stage of A. crassicaudatus is redescribed and larval stage of A. inexploratus and A. integrator are described for the first time. A particular attention is paid to the different characters of the three species. The present description of larval A. crassicaudatus is compared to that given by Stechmann (1977). Differences between the three species concern the in shape of the dorsal plate and excretory pore plate, ratio of the length of the median margins of the coxal plates and the distance of Mp1-Mp1.