Comparative morphology of mandibles of the three larval instars of A. compressa. Mandible morphology is unique to each instar and appears to suit the needs of each stage. A First instar mandibles are suitable for piercing the cockroach cuticle and facilitating a steady flow of hemolymph without serious injury to the cockroach B The second instar mandible is larger and contains a serrated edge suitable for cutting into the cockroach to facilitate entry into the host C Third and last instar mandibles appear after the larva has entered the body cavity of the cockroach to consume fat body and muscle. These mandibles appear to be suited for crushing and macerating the internal tissues D All three mandible types together to scale for comparison.