Adela (Cauchas) fibulella: 14th record for Herts, & Heath Speedwell

The title is a bit of a cheat and quite frankly a blatant pilfer of Ben Sale's far more deserving declaration of the 13th record for Herts. Last week, Ben visited Hexton Pits with the express purpose of finding Adela (Cauchas) fibulella, a day-flying moth (scarce in Hertfordshire), which feeds on Germander Speedwell (Veronica chamaedrys). Ben’s careful searching led to him finding not just 1 but 25 of these diminutive but attractive moths (for Ben's account, click HERE).

Discovering that Germander Speedwell was the all important ingredient, I knew that Bovingdon Brickworks was a possible home for the fibulella. My first opportunity to get there was Monday morning, in overcast, very blustery conditions. Not ideal but worth a punt, I thought. I started searching in the area favoured by the Brown Argus, east of Baker’s Wood, where I knew there was plenty of G. Speedwell. The third clump I came to, there they were. Five of them! One perched, the rest fluttering around the food plant. However, with minimal mothing experience, my identification was tentative at best. I found another single moth, again tentatively identified as the same species, in another area. Once home, I sent photographs to Ben and David K and they very kindly confirmed the ID as Adela (Cauchas) fibulella, a new species for the Brickworks and the 14th record of the moth in Hertfordshire.

Today, conditions were perfect to carry out a more accurate count of the Cauchas fibulella at the Brickworks. I concentrated on 2 large stretches of Germander Speedwell but also checked a couple of smaller clumps in the vicinity. The results were as follows:

Location		Grid Ref		No. of Cauchas fibulella
East of Baker’s Wood		TL00780263		14
Path into site		TL00650270		3
Open area 1		TL00450270		12
Open area 2		TL00440272		2
TOTAL				31

On the way home, I stopped off at Westbrook Hay to check another stretch of Germander Speedwell in Barnfield Meadow (TL02920565). I didn’t spend long there but counted at least 7 fibulella. It may well be that the moth is simply under-recorded rather than scarce but, even so, it’s always nice to add to the species list.

Finally, whilst searching for tiny moths on Monday, I came across what I think is probably Heath Speedwell (Veronica officinalis). I’d never seen it before and it isn’t included in the Brickworks 2011 Plant Survey. Further correspondence with Martin Parr, Conservation Manager at Maple Lodge, suggests that the plant has previously been recorded in the vicinity of the Brickworks but not actually at the site before. So, a new plant to add to the species list as well.

Heath Speedwell (flower stem)

Heath Speedwell (leaf stem)

Heath Speedwell (LEFT); Germander Speedwell (RIGHT)