The Highland Biological Recording Group

Forest Bug Pentatoma rufipes and Spiked Shieldbug Picromerus bidens		Heather Fly Bibio pomonae
The Forest Bug Pentatoma rufipes and the Spiked Shieldbug Picromerus bidens are two rather similar insects. The first is widespread, sometimes common, and is certainly under-recorded in Highland. The second has only recently been recognised in Scotland, and we have a handful of records from Eigg to our eastern border. Shieldbugs have a distinctive shape (and an even more distnctive smell if handled - they are not called 'stink-bugs' for nothing!). These two are fairly large (11-14mm) and share a general pattern of brownish ground with a paler yellow or orange spot in the middle of the back. The pictures show the easy distinction. The Forest Bug has blunt shoulders, while the Spiked Shieldbug has very sharply pointed spines. If you see a shieldbug that does not have the pale spot, or has a different ground colour, or does not match the pictures in some other way, please check the British Bugs site especially for Parent Bug Elasmucha grisea or Sloe Bug Dolycoris baccarum. The other common shieldbugs are greener (Hawthorn Shieldbug Acanthosoma haemorrhoidale, Gorse Shieldbug Piezodorus lituratus and Birch Shieldbug Elasmostethus interstinctus). Reports of other shieldbugs will be welcome. British Bugs is an excellent resource, but please do not report nymphs (the wingless young ones) unless you are absolutely certain of their identity, as they are variable and somewhat confusing. Adults should present no difficulty. In case of doubt, send a picture .		The Heather Fly Bibio pomonae is a close cousin of the St Mark's Fly B. marci. The Heather Fly is a late flyer, very similar in size and behaviour, but easily told by its bright red legs. The centimetre-long males make themselves obvious as they fly in loose swarms with obvious dangling red legs. They have large bulging eyes, unlike the females, which, with their small heads and dark wings, can look like a different species altogether (see the picture of B. marci). There are other species of Bibio in Highland at this season, but they are all smaller or lack the strkingly red legs. If in doubt send a picture for confirmation.

Forest Bug Pentatoma rufipes. Photo © Darkone at Wikimedia Commons.	Spiked Shieldbug Picromerus bidens. Photo © Tomasz Górny at Wikimedia Commons.	Heather Fly Bibio pomonae. Photo © James Lindsay at Wikimedia Commons