Long-tailed
Blue (Lampides boeticus)
Saturday,
19th September saw the first of the 2015, Sussex born Long-tailed Blues’
emerge, with two females, found by Neil Hulme at Newhaven Tidemills. Following
a lengthy break in proceedings, a pristine male was discovered at Beeding
Cement Works, also by Neil, on Thursday, 8th October. Despite a rather slow start things still looked promising, as in 2013, for a mid-late October emergence.
However, by Monday, 12th October the weather began to cool and, with the
ever-pending threat of overnight frosts, a cold northeasterly wind set in -
though the weather remained generally dry and bright. High pressure was
predicted to remain over the UK for at least ten days. Thursday, 15th
October was cold and overcast with a daytime coastal high of around 12-13°C; the
chilly northeasterly breeze still present. On a positive note, the frosts have stayed distant, at least to date, with overnight temperatures, on average, only dropping to around
7-8°C. Although wind chill is unlikely to stop emergence it would mean a lengthened
development period and also less active adults when they finally emerged,
consequently they would be much harder to locate. The presence of a hard frost would be
a completely different matter!
Complete development of L.
boeticus (egg to adult) can vary considerably with those individuals breeding
in warmer climates being substantially quicker - as short as 28 days (Cribb,
2001) - compared with those in the cooler northern hemisphere - up to 58 days
and possibly longer (D. Harris, 2015, pers. comms., 19 October; pers. obs.,
2015); confirmed by a female, witnessed in the wild state, having emerged on
Monday, 19th October after 22 days in the pupal stage and, with an estimated
egg-laying date, some eight weeks earlier, of Saturday, 22nd August. Latitude, temperature, humidity and the nature of the seasons all undoubtedly play an important role in the development of L. boeticus. This is by no means unexpected nor is it exclusive to boeticus. For example, it is believed that some slow-developing larvae of the Mountain Ringlet (Erebia epiphron) may spend two years in the larval stage, usually the result of a late spring and a short summer period.
Weatherwise, Tuesday, 20th October was the day we all been waiting for -
blue sky, sunshine, highs of 15°C and, finally, the cold northeasterly wind had
abated. However, this only lasted for a day as Wednesday, 21st was wet and
windy. Despite dull and overcast conditions, a freshly
emerged female (pictured above) was discovered at Beeding Cement Works on Friday, 23rd October. I feel sure that the 2015 season is far from over and that we may still see fresh Sussex born boeticus in November …
More
at:
Cribb, P. W. (2001). Breeding the British Butterflies. Edition 3. Orpington, Kent: The Amateur Entomologists' Society, 18, pp.49-50.
Cribb, P. W. (2001). Breeding the British Butterflies. Edition 3. Orpington, Kent: The Amateur Entomologists' Society, 18, pp.49-50.
