Survey of nocturnal parasitic wasps: request for assistance by Dr Gavin Broad
Parasitic wasps are seriously neglected insects. Very few
people realise that this group of Hymenoptera represent a substantial
portion of Britain’s (and the world’s) insect fauna,
with ~6,000 species in this country. My interests lie mostly
in the family Ichneumonidae, which is the largest family. We
know very little about most species, including such basic information
as whether or not they are widespread and what insects they use
as hosts. To partly address some of this lack of knowledge,
I am trying to build a picture of the ecology of a convenient group
of parasitic wasps, those species of the families Ichneumonidae
and Braconidae that are nocturnal and come regularly to light. The
truly nocturnal species have converged on the same overall appearance,
mostly pale red/orange, with long antennae, so that species from
completely different families may look very similar. The
pictures below show two reasonably common nocturnal wasps, an ichneumonid
By examining specimens of these species from across the country
I hope to build up a picture of the true distribution and habitat
requirements of these wasps, together with an idea of their host ranges from data that Mark
Shaw, in
Edinburgh, has been collecting. Most of the species that
come to light develop in Lepidoptera larvae, although one genus, Netelia,
develop as ectoparasitoids, attached to the outside of the caterpillar. There
are very interesting patterns of different host use, with some
species appearing to be complete specialists on one host (e.g. Enicospilus
tournieri on the Sand Dart, Agrotis ripae) and other
species attacking almost any suitably-sized caterpillar in the
right habitat.
Unfortunately, owing to the very similar colouration of most of these species, it is essential to examine specimens to see the minor morphological differences. Separation of some of the species involved is tricky and at the moment we do not really know what the most reliable characteristics are. Photographs will almost always be of no use as they will not show the necessary detail. If anybody is willing to send specimens of these species that they find in their light traps I would be very grateful. The one exception is with Ophion obscuratus, which has distinctive yellow stripes. Photographs of specimens you suspect to be O. obscuratus would be welcomed, accompanied by the appropriate data. If you find such a specimen on a sand dune, however, please do retain the specimen and send it to me as it could be the very similar and very little-known species, Ophion forticornis.
Specimens should be sent to me at the address below. My preference is for specimens in alcohol but failing that dry in tubes is fine, provided there is some tissue paper to stop them rattling around and breaking antennae. I shall sort out a supply of tubes if it looks like there will be a good response. Essential data to be included with each specimen are: 1) date; 2) grid reference, preferably 6 figure or more; 3) locality; 4) trapping method (e.g. UV, MV bulb); and 5) recorder’s name. Any other data, such as habitat information, will also be welcome.
Probably most specimens people will encounter will be ichneumonids
belonging to the subfamilies Ophioninae (particularly Ophion and Enicospilus),
Tryphoninae (Netelia) and Ctenopelmatinae (Absyrtus and Perilissus species). There
are relatively few species involved, perhaps about 60, but there
are still plenty of taxonomic problems to be solved. In
the last year I have found one Enicospilus and at least
three Netelia species new to Britain, one of them undescribed.
Your assistance would be much appreciated!
Dr Gavin Broad
Coordinator of Zoological Data and Research
The Natural History Museum
London SW7 5BD
Ichneumonidae checklist available at:
www.brc.ac.uk/downloads/Ichneumonidae_checklist.pdf