Dicranomyia (Idioglochina)


Alexander, C.P. 1921. New species of crane-flies from North Queensland (Tipulidae, Diptera). Canadian Entomologist 53: 209.


Dicranomyia is one of the largest and most widely distributed genera within both the Limoniinae and the Tipuloidea as a whole. The current concept of Dicranomyia as displayed in the world catalog of Oosterbroek (2005) shows 23 subgeneric divisions. This large number of subgeneric divisions were created from the re-classification proposed in this catalog that moved numerous subgenera formally placed under Limonia to subgenera of Dicanomyia. The genus Dicranomyia in this current state does not offer a consistent synapomorphy by which the genus is based, rather this genus is best described as a extensive group of species that shows variation around a common groundplan of wing venation (see D. (Dicranomyia) Fig. 1) and male genetalia (see D. (Dicranomyia) Fig. 2). Further revision will likely see many of these subgenera transferred to other genera or elevated to the generic level.

The subgenus Dicranomyia (Idioglochina) is based on the antennae of the adult fly, which is produced into a subserrate condition. The original description of Idioglochina states "flagellar segments with the inner face strongly produced into flattened disks, giving a subserrate appearance to the antennae, the periphery of each disk with a series of about six spinous bristles" (Alexander 1921). The male genetalia is generally of the typical Dicranomyia type with a variable rostral projection that is typically bulbous but may rarely appear short and slender. The wing venation of the subgenus is of the typical Dicranomyia type.

Dicranomyia (Idioglochina) sp. wing
Figure 1. Wing of Dicranomyia (Idioglochina) sp. (re-drawn from Alexander 19??) 

D. (Idioglochina) sp. hypopygium
Figure 2. Male gentalia of Dicranomyia (Idioglochina) sp. (re-drawn from Alexander 19??)

The 29 species of D. (Idioglochina) are most strongly represented by the 18 species that are found throughout the islands of the Australian/Oceanic Region. The Oriental Region is represented by 5 species that are distributed throughout the insular areas of the region. The subgenus is only weakly represented in the remaining biogeographic regions by 3 Neararctic species, 4 Eastern Palearctic species, 2 Neotropical species, and 4 Afrotropical species.

Larval Habitat: 

Alexander (1958) states that "all members of the subgenus Idioglochina whose habits are known are marine".