128 BRITISH ICHNEUMONS. [ Zrvphonides 


TRIBE 
TRYPHONIDES. 
The members of this tribe are among the commonest and most 
generally met with of our indigenous Ichneumonidae and it is they that 
one finds so frequently, with no idea whence they come, by swinging a net 
to and fro in the glades of woods during May and June. To the general 
collector, this group is associated with spring work and especially woods, 
though, in reality, they are no less common in gardens and about the 
borders of meadows and streams, both then and throughout the summer, 
up to quite late autumn, for they exclusively prey upon the sawflies or 
Tenthredinidae, which have so long a spell of life in the perfect state, 
ranging from the early Doleri to be met with in March to the laggard 
Emphytus serotinus, still abroad during the early days of November. 
Consequently Tryphonides may be seen throughout all but the quite dead 
months of the year, for I fancy they are peculiarly uniform in economy, 
and all hibernate as larvae in their pupal cocoons or those of their hosts, 
however many broods or successions of emergences there may be in the 
course ofa summer. Specimens of this Tribe are extremely abundant 
with us and I noted that I possessed a little over sixteen hundred of them 
when I came to work upon the present part of my volume in June, 1910; 
of these rather more than one could not be satisfactorily determined and 
I am extremely averse to erecting presumably new species in a group 
where we already appear to have fully the usual percentage of parasites 
specifically, and far more prevalently, than Tenthredinid hosts. The Rev. 
F. D. Morice has been tabulating our indigenous sawflies in a peculiarly 
concise and satisfactory manner since 1903, with the result that there are 
now very few genera to be treated of in his Help Notes, and we are 
enabled to judge the number of British species to be about three hundred 
and fifty. Upon these are already recorded over two hundred parasites 
of the Ichneumonidae alone. Consequently I have been most reluctant 
to introduce any of the latter that were not well established as British, 
though the line was difficult to draw in view of the very numerous 
erroneous determinations made by our older authors, who worked ex- 
clusively with Gravenhorst’s Ichneumonologia, even long after Holm- 
gren’s earlier works had appeared. Most of our knowledge respecting 
their economy comes from Germany and but little has been done in this 
respect in England, where sawflies are only beginning to be appreciated 
as a most fascinating group of insects. We may hope, I think, that ere 
long with the growth of this interest their parasites will be more freely 
bred and those of the present Tribe which do not prey upon them (if 
there be any such, as I have suggested under the genus Tryphon) will be 
found peculiarly interesting in unique economy, associated with insects, 
probably of their own Order, hitherto unknown to suffer from ichneu- 
monidous attacks. From an economic point of view those kinds prey- 
ing upon the numerous noxious and often appallingly destructive species 
of Lyda and Nematus, Eriocampoides and Emphytus are among the 
most beneficial of all Ichneumonidae. 
The distinctions between the Sub-tribes falling in this division are good 
in their very artificiality. Species with no hind calcaria have been picked 
