One of the more interesting biogeographical questions about the arthropod fauna of The Philippines is the question of whether Mecoptera exist in these islands. There are no confirmed records of Mecoptera being collected here. However, the family Panorpidae (scorpionflies) is a Northern Hemisphere family that is commonly encountered throughout Taiwan about 380 kilometers (235 miles) to the north of the coast of Luzon. Other species of scorpionflies are found on Mount Kinabalu along the north coast of Borneo, only 267 kilometers (163 miles) from the coast of Palawan.
Another family, the Bittacidae or hangingflies, is a cosmopolitan family found throughout Australia, southern Asia, and Taiwan. However, this family is not known from New Guinea, Borneo, other parts of Indonesia, nor The Philippines. If this family has never been found in the intervening areas between Taiwan, Asia, and Australia in the geological past, how did the family get from one region to the other?