Frass everywhere

With unexpected cloud-cover in place at dusk and the temperature forecast to remain in double figures until midnight at least, last night I made a last-minute decision to venture out to Bernwood Forest.  The cloud cover thinned then disappeared altogether by 10pm to reveal that bright moon, but while it lasted it had encouraged moths to fly and the eventual total of just over 30 species from two MV traps in the usual three hours seemed a reasonable return.  Great Prominent was the only macro to appear in any numbers (22 seen), while Silver-ground Carpet, Grey Pine Carpet, Scalloped Hazel, Poplar Hawk-moth and Alder Moth were new to me this year.  Micros included the colourful Alabonia geoffrella and an early Dioryctria abietella (I think - separating abietella from sylvestrella is not at all straightforward).  Nice though geoffrella is, one day I look forward to seeing its even smarter cousin Oecophora bractella, of which there are a handful of post-millennium records for Bucks from the area around Turville.

Alabonia geoffrella, Bernwood Forest 16th May

Dioryctria abietella, Bernwood Forest 16th May

Alder Moth, Bernwood Forest 16th May

Most noticeable by the end of the session was the huge amount of caterpillar frass on the sheets beneath the two traps, both of which were placed under the oak canopy.  There were also lots of small caterpillars abseiling down from the trees, mostly those of Winter Moth (something I've noticed during woodland butterfly transects for several weeks now).  Two larger final instar specimens are illustrated below, the first wandered onto one of the sheets while the second was found descending an oak trunk.

Small Quaker caterpillar, Bernwood 16th May

Merveille du Jour caterpillar, Bernwood 16th May

Dave Wilton
Westcott, Bucks