DIPTERA > BRACHYCERA | Higher Diptera

MUSCOMORPHA > ASCHIZA >  Syrphoidea > Syrphidae > Syrphinae > Bacchini

Platycheirus is not only the largest genus in the Bacchini tribe with 25 species as previously noted, but is also the second largest group of hoverflies after Cheilosia. Whilst there are a few species that can be readily distinguished, many are difficult, especially the females. Species are separated into six groups based on their abdominal markings and it will often be the case that individuals can only be identified as such.

... albimanus group

Four species, two of which are scarce and, therefore, only two are normally considered, Platycheirus ambiguus and Platycheirus albimanus. The latter, a sexually dimorphic species with the females having very distinctive grey spotted markings on their black abdomen, whereas the male has metallic bronze markings, is a regular spring visitor to our garden.

... manicatus group

Three species, with only two likely to be seen, Platycheirus manicatus and Platycheirus tarsalis. The first is a widespread, dry grassland species, whereas the second, which I have not encountered, is a woodland fly that's more likely to be seen in the Midlands than in Dorset.

... peltatus group

Three species, albeit one can be pretty much disregarded. That leaves Platycheirus peltatus and Platycheirus nielseni. Males can sometimes be distinguished by the shape of their front feet. Females are far more difficult, so are nearly always left as Platycheirus peltatus (group) as are any unidentified males.    

... scutatus group

Three species, although only Platycheirus scutatus is normally considered. As with the previous species, males can be confirmed by the shape of their front feet, but also by the presence of a distinctive tuft of tangled hairs at the base of the femur. If these features cannot be seen, then the individual must remain questionable. Females cannot be separated and, consequently, are always recorded as Platycheirus scutatus (group).    

... clypeatus group

This is the largest aggregate with ten species, which are separated into two smaller groups dependent on the extent of certain markings. The first group includes Platycheirus angustatus, which is a fairly distinctive species in its own right, and Platycheirus clypteus, which is difficult to separate from four other species. I've seen neither of these species despite being described as common and widespread. The other smaller group includes the wetland species Platycheirus fulviventris, which I have seen and three other much scarcer species that are rarely recorded. 

subgenus Pyrophaena

The final grouping consists of another wetland species Platycheirus granditarsus, which is a widespread and readily recognised hoverfly that I've yet to find, and Platycheirus rosarum, which can usually be identified by the unusual shape and markings on the abdomen. Unfortunately, I only have one photo of this species at present from which only the slight bulge towards the rear of the abdomen can be determined.

Sept.24