228 BRITISH ICHNEUMONS. l-''^^"" 



and a little clouded ; stigma and radius infuscate, radix and tegulae 

 nigrescent ; areolet large, sessile or subpetiolate and nearly regularly 

 triangular ; ner\ellus intercepting slightly below the centre. Length, 

 1 8 — 20 mm. 



I'his is the largest and stoutest species of the genus ; it is very like 

 Jlf. piviplafor but is larger \vith the frons more impressed, mesonotum 

 more nitidulous basally, metathorax much more strongly rugose and the 

 coxae black. The J is rarer and more slender than the 9 '^'^^^ not pale- 

 marked. 



Bouche says (Naturg. 144) the larva has only the vertex of the dorsal 

 abdominal segments a little gibbous "der Riicken der Abschnitte ist etwas 

 bucklig." 



It is distributed throughout northern and central Europe where it occurs 

 in May, June and August on oak trunks and umbelliferous flowers ; in 

 Belgium it is not infrequent in the latter month on old sallows. Graven- 

 horst records it from Netley in Shropshire, Bridgman from Sparham in 

 Norfolk and Harwood from Essex ; Bairstow mentions it as doubtfully 

 occuring in Yorkshire (Trans. Yorks. Un. 1880, p. 108). I possess an 

 ancient female, labelled " Bury St. f^dmunds," from Dr. Wratislaw's col- 

 lection''' and have seen another bred by Beaumont at Blackheath from an 

 apple stump, probably from Sesia myopacformis, early in July, 1898. 

 Several of both sexes were sent to me from Bloxworth in Cambs., where 

 they had been bred from a species of Sesia (probably S. hembeciformis) in 

 osier stumps on 29th July, 1902. Bouche (Naturg. 145) says that this 

 species is parasitic upon the larvae of Cossus h'gtiipcrda, that it passes the 

 winter in the host's cocoon and emerges in May, two or three specimens 

 being generally bred from a single host. This statement appears to have 

 been simply copied by Holmgren and subsequent authors (though Fitch 

 and Brischke, who describes the cocoon as brown and cylindrical, appear 

 to have bred it from the same host) till it has given rise to the supposition 

 that M. setosus was especially attached to that host, which the above 

 breedings will dispro\'e, though all were from lignivorous lepidoptera. 

 A final instance and a very interesting one is brought forward by Chap- 

 man, upon Bignell's authority (E. M. M. 1898, p. 5) : He noticed at Sterz- 

 ing in the Tyrol that an entomophagous larva of this species constrained 

 its host to spin a cocoon when only in its second year of growth, which 

 is a proceeding it naturally undertakes only just before pupating in the 

 spring at the end of its third year. Only a single specimen emerged : 

 perhaps if more than one had been present the host would have lived its 



* This collection amassed about 1865 and composed, I believe entirely, of Suffolk insects found its 

 way at Wratislaw's death into the hands of J. B. Hod^kinson and I have seen a memorandum of his 

 acquisition which passed, with at least the Ichneumonidae, to my friend the late Alfred Beaumont. 

 When the latter died while working at insects in his study in Feb. 1905, the Ichneumonidae were 

 bought by A. J. Chitty, whose widow has just (Feb. igo8) presented the whole of his extensive collec- 

 tions to the Hope Dept. of the Oxford University Museum, where they will find a permanent abode. 



