Further notes on Callicera spinolae and C, aurata, and another hoverfly Criorhina ranunculi
However, in 2001 C. spinolae also turned up at Wimpole Hall in Cambridgeshire (Damant 2002)
with C. aurata. Larvae of both species were found in Beech and Horse-chestnut rot-holes full of
water (but drying out in the summer). Two larvae were collected from rot-holes in Horse Chestnut
and the two species duly emerged as adults - C. aurata in June with C. spinolae pupating and
emerging in August. At Hylands Park specimens of C. spinolae were observed at flowering Ivy on
the 21st and 24th September.
On 12th September 2002 I was investigating the patch of Ivy where C. spinolae had been found the
previous year in order to confirm that it was still found in the park (and hence probably breeding).
Although attracting the attention of numerous flies and wasps, the Ivy was barely into flower. I
noticed a Callicera species at rest on an Ivy leaf, and after again capturing the specimen by hand I
noted a distinct lack of dark banding on tergites 2 and 3 and the female specimen also had noticeably
dark femora, on all legs - the specimen thus proving to be Callicera aurata (formerly misidentified
in the UK as C. aenea). This neatly confirms Rotheray's assertion that the two Callicera species
can overlap (C. aurata is said to have a flight period as late as October). I suspect also that both
Callicera species have established breeding populations in the park, probably in some of the older
Horse Chestnut trees.
Criorhina ranunculi (Panzer)
This notable species is not uncommon in Britain. It is the largest and most spectacular of the four
British Criorhina, Despite it being a 'southern' species (almost all records come from below a
horizontal line through Leeds) it has never before been recorded in Essex. This is possibly due to
it being an excellent bumblebee mimic and probably also because it has a very early flight period.
It can be out in March and it peaks in late April. Interestingly it occurs in two colour forms, both
noted at Hylands Park. Both forms are mainly dark black but one has a bright orange-red tip to the
abdomen rather like the bumblebee Bombus lapidarius; the other has a white tip. Larvae are said to
develop in rot-holes in deciduous trees - at Hylands Park almost certainly Horse-chestnut.
Hylands Park records of Criorhina ranunculi:
24/4/02 One female noted investigating a rot-hole at the base of a huge Horse-Chestnut
pollard (TL 687048)
15/5/02 Another individual also seen investigating damp rotting wood at the base of a
Horse-chestnut tree in the formal gardens (TL 683044).
31/5/02 A female of the white-tailed form noted on the blossom of Cockspur Thorn
Crataegus crus-galli also in the formal gardens (TL 684044).
References
BALL, S.G. & MORRIS, R.K.A. (2000) Provisional atlas of British hoverflies (Diptera. Syrphidae).
Huntingdon: Biological Records Centre.
DAMANT, S. (2002) Further hoverflies at Wimpole Hall. Bulletin of the Dipterists Forum 53: Hoverfly
Newsletter: 6.
HANSON, M..W. (2002) Callicera spinolae Rondani at Hylands Park. Essex Field Club Newsletter 37: 15.
ISMAY, J. (ed.) (2000) Report on the Diptera of Epping Forest. Report for the Corporation of London.
Essex Naturalist (New Series) 19 (2002)
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