A walk around the lanes of lower Llangynwyd with fine weather meant that the summer migrants are now starting to return. Both Willow Warbler (2) and Blackcap (2) were singing and Chiffchaff (10) numbers increasing. Overhead raptors were soaring in Buzzard (8), Red Kite (1) and Goshawk (female) with a Swallow flying north also.
There were less butterflies than there have been lately with only Comma (1) and Peacock (2) present. Tree Bumblebees are becoming more noticeable and there are still good numbers of Honey Bee feeding. Hoverfly numbers are yet to pick up but I did have the first of the year for Melanostoma scalare. I also recorded two new flies for myself in the valley a Tachinid and a St Mark's Fly species, although Paul Tabor has recorded them before me, see below.
The Tachinid fly
Gymnocheta viridis is often found sunning itself on the tree trunks in sun traps in the woods. As I said in a previous post Tachinid flies are parasitoidic, that is they lay their eggs in the host caterpillars and the larva/grubs then eat the host alive before pupating. This species has been recorded inside the larva of the moths Shaded Broad Bar, Small Wainscot, Common Rustic and Small Dotted Buff. Not a rare species by any means but is new for the valley. There is one similar species but that flies in late summer and has only 1 record for Great Britain, while Gymnocheta viridis is a spring species.
There are 18 species of Bibio (St Mark's Fly) of which four are in the 6-8mm range, three have all black legs (male) and the other has a certain amount of deep red/rusty brown tibia like the picture below. So this is
Bibio lanigerus and has been confirmed on Irecord. There have been few records for Glamorgan but is probably overlooked as it is regarded as common in Great Britain.
map of Bibio lanigerus Glamorgan records. Dark red are confirmed records, pink are unconfirmed records.
male
Melanostoma scalare - very common but first of the year for the valley.
