Dance Flies and Missing Moths

On Skye last week I spotted some impressive flies which turn out to be Empis borealis, a species of Dance Fly or Dagger Fly. Thanks to Tony and Seth for i.d. This particular species of fly exhibits sex-role reversal in its mating process, with female flies aggregating in swarms to compete for male choice. Female fly swarms change their flying behaviour in the presence of males, who present nuptial gifts to females before mating. The name Dagger Fly comes from the long downward-pointing probosis used for spearing other insects.

Empis borealis

Prior to this year Pammene giganteana (Early Oak Piercer) was known in Scotland from just four VC’s and a handful of records. However, it is known that it comes to lures for Grapholita molesta (MOL), Grapholita lobarzewskii (SKI) and Grapholita funebrana (FUN).  Use of these lures has resulted in many new records in England and southern Scotland.

The larvae feed on spongy oak galls but oak trees are scarce on Raasay. There are a few near Eyre and some near Dun Borodale and in both places I have had a go with a MOL lure. The weather has been irritatingly cold, only reaching 6 or 7 C most days – the absolute minimum for these micromoths to fly, and I have not succeeded. Maybe next year I will try in Sleat where there is a lot more oak.

Lure on oak at Eyre

Tags: ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s


%d bloggers like this: