52 BRITISH ICHNEUMONS. {Thirsilochus 



shinintr ; sternauli elonfj;ate and deeply impressed, notauli apically subin- 

 dicated ; metathorax finely scabrous and not very dull ; basal area 

 variable, subquadrate or twice longer than broad, always distinct ; petio- 

 lar area entire, not discreted, and extending beyond centre. Abdomen 

 normally compressed and discally black with second segment sometimes 

 obsoletely badious, the following segments laterally subrufescent below ; 

 basal segment glabrous and nitidulous, discally sulcate to beyond its 

 centre with no aciculation, of $ linear and of 9 with postpetiole apically 

 subexplanate ; second segment with distinct though small thyridii, of 9 

 a little and of $ strongly longer than broad ; terebra as long as abdomen 

 and not very slender. Legs testaceous with only coxae black; of normal 

 length and not very stout ; hind trochanters subHavidous. Wings hyaline 

 with stigma large and entirely nigrescent-piceous, tegulae testaceous ; 

 radius apically straight ; recurrent nsrvure sometimes exactly continuous 

 with, or emitted distinctly beyond, the areolar. Length, 4-4.75 mm. 



1 do not consider anyone has correctly recognized Ratzeburg's species; 

 he gives the antennae with sufficient accuracy as 22-23-jointed; Holm- 

 gren's 9 with twenty-three joints in the flagellum must be distinct. It 

 differs from P. 7)ioderator, var. 4, Grav., in the pedal colouration, from P. 

 caudalus, Holmgr., in the paucity of flagellar joints and, sw Thoms., also 

 in the strong sternauli. 



Ratzeburg tells us that Tischbein bred both sexes of this species from 

 the heteromerous beetle, Oirhcsia micaiis [cf. Grav. LE. i. 721), which 

 appears to suffer from many Braconidous enemies. Possibly the present 

 species is hyperparasitic upon the latter. Wherever Oirhcsia micans 

 occurs, always in Boletus fungi on old elm trees, about Ipswich Mefeoriis 

 obfuscatits, Nees, is to be found; thus a fungus taken at Foxhall on 

 October 17th, 1897, produced several $ 9 of T. Orchesiae on ist April, 

 1898 (from which the above description is drawn), while by January 12th 

 I go I, more of both sexes, together with many of the beetle and M. ohfus- 

 cii/iis had emerged. A second fungus yielded only the coleopteron and 

 Braconid. But a third produced, besides these, ten 7'. Oir/hsiai' in equal 

 sexes and a female Proctotiypes parvulus, Hal. 



14. moderator, Hohugr. 



Ichiteianon nio'derafor, Linn. S.N. 1758, 564 ; Opiiiou moderator, Fab. Piez. 

 137; Porizon moderator, Gr. I.E. iii. 783, c? ?; Cynipsic/iiieiimnii strohilcl/ac, 

 Christ, Naturg. 1791, p. 385, pi. xlii, figg. 4 cf 5 (?). T/icrsiloc/nis moderator, 

 Holmgr. Sv. Ak. Handl. 1858, p. 144, ?; Brisch. Schr. Nat. Ges. Danz. 18S0, 

 p. 193; Thoms. O.E. xiii. 1395, <? ? . 



Head dull and almost broader than thorax with vertex rather broad 

 and posteriorly hardly constricted ; cheeks subelongate and subbuccate ; 

 clypeu-i apically rounded and subelevated, usually rufescent with the 

 mouth infuscate. Antennae hardly extending to thoracic apex; flagellum 

 slender and filiform, of 9 with about twenty joints, of which the first is 

 ratln;r longer than the second and second longer than broad ; scai)e, 

 especially in ^, often rufescent beneath. Thorax coarctate, dull with 

 notauli wanting; metathorax rugosely punctate and subelongately pubes- 

 cent; basal area elongate and linear, petiolar area extending beyond 

 centre. Scutellum apically compressed, in (J subacumniate; pleurae dull 

 and finely alutaceous, with no sternauli. Abdomen subfusiform and im- 

 maculate black or centrally badious; basal segment subelongate and little 



