Bassus | BRITISH ICHNEUMONS. 83 

the second segment. Pfankuch remarks upon the extreme rarity of males 
in this species; with us both sexes are almost equally common. 
The tricoloured hind tibiae will instantly distinguish it from all other 
Bassides. 
This is a very abundant species with us and is one of the most cosmo- 
politan of all Ichneumonidae; Ashmead says its distribution extends 
throughout Europe, Asia, Africa, Australia, New Zealand, Chatham 
Islands, Hawaii, Japan, the West Indies, and both North and South 
America; I have specimens from India (Quetta), Bucharest, etc., and it is 
common in the Canary Islands. In Britain it is found from the Isle of 
Wight to Whitby and the Isle of Man; but I have heard of no Scotch 
captures, though it doubtless occurs there and was, according to his MS. 
in Dublin Museum, found commonly by Haliday in Ireland.* It first 
appears on 27th May, is most abundant from the end of July to the begin- 
ning of September, and my latest date of capture is the 23rd of the latter 
month. That it is attracted by artificial light is, I think, proved by my 
finding one sitting on a table beneath a lamp during the evening of 31st 
July, 1900; and I have frequently seen it on the inside of windows. It is 
most commonly found by sweeping, but may often be observed upon the 
leaves of horseradish, on oats, reeds and the flowers of Heracleum, Angelica, 
Statice, Achillea and thistles, not uncommonly in salt-marshes, though it 
has no especial penchant for damp situations. On 25th to 29th July, 1899, 
I noticed that the females were exceedingly abundant upon Polygonum 
growing at the base of a corrugated iron paling on the beach at Slaugh- 
den; they were running up and down the stems and leaves, poking both 
antennae at once into the cups surrounding the base of the branches and 
keenly searching for some host which was invisible to me. This species 
was first bred by Ratzeburg from the larva of some Sy7phus fly in Saxony ; 
subsequently Dr. Giraud raised it (Ann. Soc. Fr. 1877, p. 408) from Syr- 
phus balteatus and another species, the MS. 2. pipizae, Gir., from Pipzza 
noctiluca ; Brischke says of it “aus Syrphus-Maden erzogen,” in Prussia ; 
and its association with these flies, which prey on Apfzdidae, was sug- 
gested by Gravenhorst, who tells us that it was captured among Aphides 
near Helmstadt, as well as upon umbels. Van Vollenhoven says (Pinac. 
pl. 1) that it had long ago been noticed that this species is parasitical to 
the larvae of Sy7phus Pinastri (= ? corollae) ; but his other records of its 
emergence (copied from Kirchner, Cat. 84) from a larva of the phyto- 
phagous Coleopteron, Adimonia rustica, Schall. (= pomonae, Scop.) and 
from Zorrices are most probably errors. Bignell bred a specimen (Entom. 
1884, p. 167) from the indurated larval skin of an unknown species of 
Syrphus on 3rd June, 1884, which he had found during the preceding 
October in Oreston Quarry, in Devon, preying upon Aphis Jacobaeae, 
Schr.; he adds that the host-larva had entered its puparial state at the 
end of October, and remained quiescent till the parasite’semergence. In 
his South Devon list of 1898, he says (p. 42) that “this is a common 
parasite on the larvae of the Hovering fly (Syrphus), the larvae of which 
* Detailed localities :—Alderney, Lands End and Cremy] in Cornwall, Newton Abbot, Cornworthy, 
Bickleigh and Ivybridge in Devon, Portland undercliff and Isle of Purbeck, Glanvilles Wootton, 
Littlehampton, Hastings and Guestling in Sussex, the Deal sandhills, Abinger Hammer, Guildford, 
Shere and Greenings in Surrey, Plumstead, Chiswick and Acton, Felden in Herts, Shotover near 
Oxford, St. Albans, Nunton in Wilts, East Ilsley in Berks, Redland near Bristol, Nottingham, and 
Cadney in Lincs., Gosfield in Essex, West Runton, Hunstanton and Kings Lynn in Nortolk, Tim- 
worth, Tostock, Aldeburgh, Benacre Broad and Oulton Broad in Suffolk, Lastingham, Storthes Wood 
and Whitby in Yorks, Isle of Man. I have taken it at Ryde and Norton Wood in the Isle of Wight, 
Lyndhurst in New Forest, at Holme, Filby Broad, Horning and Cromer in Norfolk, at Peterborough ; 
and in Suffolk at Southwold, Easton Broad, Bentley Woods, Tuddenham Fen, Barton Mills, Sother- 
ton, Lackford, Finborough Park, Felixstowe, Slaughden, Dodnash, Claydon bridge, Lowestoft, Cor 
ton, Henstead, Barnby Broad and in my paddock at Monks’ Soham, G2 
