2018 has been an interesting one for Diptera in the Natural History Museum’s Wildlife Garden in South Kensington. The stand out highlight has to be David Notton’s find in May of a specimen of not just a new species, but a new family for Britain! The tiny Cryptochaetum iceryae is a parasitoid of scale insects https://twitter.com/NHM_Bees/status/1027250059782615040.
As well as the dedication of the Museum’s entomologists paying off, interesting records of larger Diptera are being added even by casual visitors and non-specialists. A visitor to the May bioblitz caught a Heineken Fly Rhingia campestris. During the same event I found a Black Snipefly Chrysopilus cristatus – with another a few days later. These are common species but nonetheless new for the site. Also in May, David Notton swept two Tree Snipeflies Chrysopilus laetus. This is a rare Snipefly with diffuse spotting on the wings and orange body and few previous site records. I was lucky enough to chance upon one of these a few days later. The fairly common, delicately built and green-eyed Little Snipefly Chrysopilus asiliformis is a more frequent casual observation. Soldierflies and their allies such as the Snipeflies are attractive and a number of species are fairly distinctive, giving the non-dipterist a chance to have a go at them.
Chrysopilus cristatus
Chrysopilus laetus
The Drab Wood-soldierfly Solva marginata was formerly rare but is now understood to be increasing, though still a good find. In the Wildlife Garden it is believed to use rotten standing deadwood in the Poplar trees. This June-July I found them on several occasions, including seven in one day. Although superficially drab, if you get the chance to examine them closely they are subtly beautiful with yellow bands and golden hairs.
Solva marginata
Because Soldierflies are seldom abundant and so have sometimes been overlooked, they offer the chance to add new records for the site. For example, in June I found the Black Colonel Odontomyia tigrina –new for the site - by the main pond. Many species have entertainingly militaristic common names such as the (beautifully-marked) Four-barred Major Oxycera rara, which is seen occasionally. The large but elusive Banded General Stratiomys potamida is occasionally seen, by the main pond. In September search for the iridescent blue and orange Twin-spot Centurion Sargus bipunctatus, if only so you can mutter its common name to the bemusement of passers-by. And, very importantly, take a moment to marvel at the diversity and beauty of these insects!
Oxycera rara
Joe Beale 28 Aug 2018
