Fireflies are sensitive to pollution in the environment and often chosen as indicators in the studies of environmental protection. However, during non-adult active season of fireflies environmental investigation requires identification on the larvae morphology. Hence, accurate identification of larvae species is very important. Due to the scarce systematic studies on the association of adult fireflies with its immature form, it is difficult to correctly identify larvae species of firefly. Therefore, this study reviewed the morphology of the five larvae species of the genus Pyrocoelia Gorham in Taiwan, and provided a description and illustration in color. We also established diagnoses and provided keys of Pyrocoelia Gorham larvae, and discussed the variations of body color on larvae.