Mesochorus] BRITISH ICHNEUMONS. 321 



8. testaceus, Gniv. 



Mcsoctionis fcstcicciis, Gr. I.E. ii. 973, j; Ilnlm^'r. Sv. Ak. Hantll. 1858, 

 p. 128; Tlioms. Ann. Soc. Fr. 1885, p. ;«7, <^ ? ; (?) Fonsc. lib. cit. 1852, p. 439, 9 

 ct Brisch. Schr. Nat. Ges. Danz 1880, p. 181, ,f ? . 



A pale testaceous species with s[)arse black inarkiiii^fs, tlie pleurae 

 smooth and face finely punctate. Head with tace (inel)- punctate and in 

 <^ usually substramiueous ; ocellar region sometimes nigrescent. Thorax 

 laterally smooth and usually broadly flavous-marked. Scutellum llavidous. 

 Abdomen with first segment ferrugineous or piceous, basally paler, the 

 second piceous with its ape.x and usually centre testaceous; the following 

 segments pale, rarely laterally subinfuscate. Legs pale flavous, with hind 

 tibiae and tarsal joints usually apically infuscate. Wings hyaline with 

 stigma either testaceous or piceous, and tegulae whitish. Length, 

 7-9 mm. 



Similar in size, central petiolar spiracles, continuous basal nervure, sub- 

 petiolate areolet, quadrate face, longer lower mandibular tooth, basally 

 black abdomen with triangularly flavidous second segment, the structure 

 of the claws and not subulate terebra to M. vitticoUis ; though distinct 

 therefrom in its darker stigma, basally testaceous petiole, laterally sub- 

 margined postpetiole and not black-marked hind tibiae. Very like 

 M. fulgurans in colour but more flavidous and slender with two basal 

 segments always partly badious, stigma often darker and the recurrent 

 nervure emitted from centre of areolet. 



Not common in north and central Europe ; found during June in 

 Belgium; and bred in France from Tachiua flavcscais (Giraud, 1^77), 

 from CliUHllaria amcrinac, Dinura stilala, Poecilosoma candidaia, and Tachina 

 larvarum (Gaulle) ; Eupilhtcia pimpincllata is also instanced as host by 

 Brischke in Prussia. A good deal scarcer with us than the last species and 

 ap})arently confined to Tenthredinid hosts: Brundall near Norwich in 

 May (Bridg.), Kings Lynn in Norfolk (Atmore), two at Shere in Surrey 

 (Capron), Banchory in Kincardine during September, iqio (Elliott, mis- 

 named J/, vitlicollis by me, E.M.INL 191 1, p. 93). Nearly all my examples 

 consist of two batches ; one comprising a dozen of both sexes is from the 

 New Forest (Miss Chawncr), the other comprising about a score of males 

 only, emerged on 14th May, 1901, through four distinct holes \\\ a Cimhcx 

 cocoon " formed by a large white sawfly larva, with a dark medio-dorsal 

 stripe, beaten from birch at Paul's Cray Common near Chislehurst on 

 22nd September, 1900" (Montgomery); doubtless this host was C. fiiiwr- 

 ala, L.=-sylvarum, Cam. It lias only occurred to me towards the end of 

 August, 1905, also by beating birch, at Tuddenham Fen in Suffolk. 



9. semirufus, Ifolmgr. 



McsocJionis xcininifns, Holmgr. Sv. Ak. Hand!. 1858, p. 125; Brisch. Schr. 

 Nat. Ges. Danz. 1880, p. 180; Thorns. Ann. Soc. Fr. 1885, p. 337, ^ ? . 



A i)ale species, with the thorax and abdominal base black; pleurae 

 punctate. Head narrow behind the eyes; face transverse and except 

 apicallv ruf(>scent, with the mouth, cheeks, frontal shortly and other orbits, 

 stramineous; mandibular teeth of equal length. Antennae paU-, fniely 

 pilose and as long as body. Thorax stout, finely punctate and somewhat 



