DIPTERA > BRACHYCERA | Higher Diptera

MUSCOMORPHA > ASCHIZA > Platypezoidea > Platypezidae (34 species)

(subfamilies: Callomyiinae, Microsaniinae and Platypezinae)

Following on from the introduction and general information on the previous page, here is a little bit of detail regarding the Callomyiinae subfamily and the two species that I've photographed to date:

Callomyiinae

Agathomyia (11), Callomyia (4) and Platypezina (1)

The members of this subfamily are distinguished by having a posterior cross-vein (dm-cu) that encloses the discal cell, and vein M continuing near enough straight to the wing margin without a fork (apart from Platypezina connexa); acrosticals present between the dorsocentrals; first segment of the hind tarsus is greatly extended and roughly as long as segments 2-5 combined.

Agathomia

Third segment of the antennae elongate; tip of the middle tibiae with a central ventral bristle. Males and females are separately keyed. The females have distinctive abdominal markings, so I presume that most species can be identified with reasonable confidence from photos. The males may be a bit more difficult, although they can also be separated to some degree by their body colour. Otherwise, it's a case of checking details such as various leg bristles that are probably not going to be picked up in photos as the species are all rather small. 

Agathomyia falleni

A late season species that not that long ago seemed to be restricted to the south-east as most records were from East Sussex, although all from one particular recorder. More recently, it has been recorded from much further afield as far north as South Yorkshire and west to Wiltshire and South Wales. There are no more than 26 records though on either the NBN Atlas or in iRecord. I believe that my record is the only one from Dorset.

Females have a generally grey-dusted thorax with a slight bluish sheen coupled with a dull orange-yellow abdomen with more or less dorsally interrupted brownish-coloured bands that do not reach the fore and hind margins of the tergites. The males have a similarly coloured grey-dusted thorax and a mainly orange-yellow abdomen, but with only a vague brown band in the middle of each tergite; and further distinguished by the first hind tarsomere being noticeably broader than the hind tibia. 

Agathomyia unicolor

Apparently common and widespread and, as noted on the previous page, actually the fourth most frequently recorded platypezid according to the distribution data on the NBN Atlas with 66 observations but, for some reason, with only ten submitted to iRecord. I'm not sure why, but even the NBN records only have one sighting from Dorset, which was over twenty years ago.

The females are actually quite similar to the previous species, but with a slightly darker more brownish-grey thorax and a somewhat variable yellowish-brown abdomen. In contrast, the males have a mainly black body with some grey and brownish dusting; with the first hind tarsomere being only a little broader than the hind tibia; and the mid tibia having a strong posterodorsal bristle near the middle and a weaker dorsal bristle below.    

The larvae of both of these Agathomyia species are known to develop in the common, small-pored Smoky Bracket fungus Bjerkandera adusta.

NB. the identities of the individuals featured below have been checked and confirmed by Ryan Mitchell who is one of the country's leading authorities on Platypezidae species.

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Oct.24