The cytology and arval morphology of the Victorian representatives of the subgenus Kiefferulus of the genus Chironmus (Diptera: Nematocera)

Abstract

The larvae of C. martini, C. intertinctus, and the Botanic Gardens species can be distinguished from other Victorian "blood worms" by the structure of the hypostomial plate and the presence of only one pair of blood gills. It is also the case that the larvae of any one species differ from those of the other two in the average length of the fullgrown larva, the length of the blood gills, and the presence of a feeding brush in C. martini. In the adult form the Botanic Gardens species is taxonomically identical with C. intertinctus. All three species possess the usual four salivary gland chromosomes and each species is quite polymorphic. Twelve inversions are known from C. intertinctus, six from the Botanic Gardens species, and nine from C. martini, which is unusual in being polymorphic for three duplications or deficiencies. It is suggested that the similarity between C. intertinctus and the Botanic Gardens species is due to convergence because of their similar ecology.