A Dipterists year. May.
May is my favorite time for walking in the British woodlands, with the less dense foliage of the trees, there is often an array of colourful flowers that attract insects.
Myopa testacea Linnaeus, 1767. Conopidae.
This Conops fly first appears in the spring and my find was along a path at the bottom of a small steep sided woodland on the chalk.
M. testacea parasitises some of the common spring
Andrena mining bees, inserting an egg into the abdomen of the chosen host, hence their often used English name of bee grabbers, the mature Conopid larva eventually pupates within the host. A fairly widespread but local species.
Myopa testacea. Chalk woodland, Wiltshire, May.
Sphegina clunipes Fallén, 1816. Syrphidae.
This very small unusual looking hoverfly was found in the small woodland mentioned in connection with the last species, the only place I have yet observed it. It has a dainty flight, but seems to hardly ever rest as it flits through the undergrowth in dappled light. This species likes damp woodland, often near a stream, the larva develop under dead bark on living trees or under the bark of fallen trees in shady conditions.
Sphegina clunipes. Chalk woodland, Wiltshire, with habitat. May.
Rhingia rostrata Linnaeus, 1758. Syrphidae.
Rhingia rostrata is the less frequent of the two snout hoverflies that occur in Britain, it was once much rarer but in recent years it has spread across Southern England, but it seems to be currently absent from my region. My first finds were in a limestone wood in Somerset where the males especially sought out the Ramson,
Allium ursinum flowers but it was not especially common there, occurring with the darker and more frequent
Rhingia campestris.
Rhingia rostrata 1 & 2 male, woodland, Somerset, May. 3. Female, woodland in Shropshire, May.
Mesembrina meridiana. Muscidae.
Known in English as the Noon fly, this large species like to sit about sun bathing in well wooded country, it also visits dung in which the larvae breed, a common and widespread species in Britain.
Criorhina asilica Fallén, 1816,
Criorhina berberina Fabricius, 1805,
Criorhina floccosa,Meigen, 1822. Syrphidae.
One remarkable day in Savernake Forest in Wiltshire, on a bright summer's morning, produced not only the other three local species of the bee mimicking
Criorhina in one area but also two mating pairs, which are very rarely seen. The larvae of all three species live in rotting wood. Both forms of
Criorhina berberina were encountered, the buff form
oxycanthae, a mimic of Carder bumblebees and the typical form, an excellent mimic of
Bombus hypnorum. Several of both forms of
C. berberina were flying around the base of an old sycamore tree and slowly quartering the ground around, obviously looking for a newly emerged female, or perhaps waiting for one to emerge. On this and subsequent visits, I saw a number of
Criorhina floccosa males holding territories around the base of large old beech trees within the forest, usually there was one individual but if another appeared they would engage in combat, locking together, often rolling around on the ground in the dead leaves, the victor emerging to sit on his preferred spot on the moss covered base of the tree, ready to claim any emerging or visiting females, while the vanquished retreated to try his luck elsewhere. The
Criorhina asilica males were very active along a woodland ride, flying at speed, rarely resting, on their endless search for females. Occasionally I saw the males of both
C. asilica and
C. floccosa in this area, visiting the yellowish-green flowers of the sycamore trees.
1 & 2.
Criorhina floccosa mating pair and male at the base of a beech tree
3 & 4.
Criorhina asilica mating pair and a male.
4 & 5.
Criorhina berberina male form
oxycanthae and typical form.
Meligramma euchromum. Kowarz, 1885. Syrphidae.
One May morning in Savernake Forest, I found basking in the sunshine
Meligramma euchromum, a really good find because it is a rare and elusive species that is thought to be mainly arboreal. I only managed one quick shot, before it vanished upwards.
Meligramma euchromum male. Savernake Forest, May.
