A Revised Nomenclature for the Chaetotaxy of the Mosquito Larva (Diptera: Culicidae)

TLDR: It is suggested to prepare a uniform nomenclature which would take into account all the established elements of the chaetotaxy of the fourth instar mosquito larva, allow for the later inclusion of certain elements now poorly known, show homologies where they have been established, and be equally suitable for anophelines and culicines.

Abstract: The recent recognition of species complexes within populations formerly believed to represent a single species has focused the attention of students of mosquitoes to a reexamination of characters previously used in the separation of species and to a search for new morphological features useful in diagnosis. The immature stages of mosquitoes offer a greater variety of morphological characters which can be studied quantitatively, analyzed, and used for recognition of species than do the adults. Until recently almost all the attention was paid to the head, a few thoracic and abdominal hairs and the terminal abdominal segments of the larva, and the trumpets, paddles and a few abPom,nal hairs of the pupa. The larval characters used have not been entirely satisfactory and in the last few years the pupal stage has attracted more attention in the search for additional diagnostic characters. This interest in the pupa has culminated in the work of Knight and 'Chamberlain (1948) who made a comparative study, devised a new nomenclature, and illustrated the complete chaetotaxy of representatives of practically all the genera. The study of the larva has not progressed as rapidly, perhaps because of the greater complexity of the chaetotaxy, since the larva has upward of 200 pairs of hairs while the pupa appears to have about 105 pairs. The complete larval chaetotaxy for the majority of the genera is still unknown. In the course of a study on the genus Uranotaenia from the Solomon Islands, the complete larval chaetotaxy of seven species was described and figured by the author. In the preparation of descriptions it became evident that the existing nomenclatures were not entirely satisfactory as various combinations of numerical, alphabetical and nominal terminologies have been used by different workers according to their individual preferences and no system used all the elements of the larval chaetotaxy known at the present time. It seemed advisable, therefore, to prepare a uniform nomenclature which would (1) take into account all the established elements of the chaetotaxy of the fourth instar mosquito larva, (2) allow for the later inclusion of certain elements now poorly known, (3) show homologies where they have been established, (4) be equally suitable for anophelines and culicines, and (5) be easy to use in descriptions.