Slilpni4S.] BRITISH ICHNEUMONS. 24I 



STILPNUS, Gnwenhorst. 

 Gr. I, E. i. 664 (1829). 



Small, smooth and strongly shining insects, with the abdomen more or 

 less flat and ovate. Head short and transverse, with oval and jjrominent 

 eyes ; clypeus not distinctly discreted, quite flat, apically slightly rounded, 

 with basal lateral foveae. Antennae normal, slightly attenuate basally, 

 consisting of nineteen (in $ fourteen to seventeen) joints, of which the 

 third is about twice longer than broad and conical, the following soon 

 becoming as broad as long and cylindrical. Metathorax short and not 

 produced beyond the base of the hind coxae, all the areae sub-entire but 

 with the areola wanting and the dentiparal transverse, apically truncate ; 

 longitudinal costae of the petiolar area usually strong ; spiracles circular 

 and very small, approaching the lateral costae. Scutellum convex and 

 apically obtuse. Abdomen petiolate, usually deplanate, smooth and 

 strongly nitidulous, of 9 sub-orbiculate and broader than the thorax, 

 of $ fusiform ; basal segment narrow, sub-linear or with the post-petiole 

 slightly explanate, carinate and aciculate, with spiracles behind the centre ; 

 remainder of abdomen strongly deplanate and nitidulous ; second segment 

 with lateral impressed lines and distinct epipleurae, of $ strongly, of $ 

 slightly transverse. Legs slender. Wings ample, areolet pentagonal and 

 apically sub-complete ; stigma broad, emitting the radial nervure from its 

 centre. 



Haliday and Gravenhorst noted the affinity of this genus with Hemifeles, 

 than which the abdomen is distinctly shorter and more circular ; Curtis 

 first drew attention to its similarity to Atractodes ; the abdomen is not 

 centrally plicate ventrally after desiccation. 



This ill-defined genus was placed originally, like Pristiceros and Ischnus, 

 as a sub-genus of Ichneumo?i or, as we should nowadays say, among the 

 Ichneumoninae, whence Taschenberg, who knew but one species, trans- 

 ferred it to the Cryptinae, in spite of its hardly exserted ovipositor. At 

 that lime it would have been more correctly placed among the Ophiouinae, 

 but now that Thomson, following Forster's impossible classification to a 

 reasonable extent, has indicated its close affinity with Atraclodes, and has, 

 perhaps more correctly, placed the whole group in the Cnp/iiiae, it were 

 better to treat of it here, though, wherever it be placed, it must remain to 

 some degree aberrant. Fitch says that the fact of a species having been 

 bred from a cocoon of its own manufacture shows that the genus does not 

 belong to the Ichneitmotiinae, and the same may be said with almost equal 

 propriety of the Cryptinae^ in spite of the more or less distinctly penta- 

 gonal areolet. 



Table 0/ Spci les. 



(6). I. Head not abruptly contracted behind the eyes. 

 (3). 2. Abdomen strongly convex, black ; flagellum 



of $ stout, not reaching petiole i. (;.\0.\TES, Grav. 



(2). 3. Abdomen deplanate, centrally red ; flagellum 



normal, reaching petiole. 



(5). 4. Second segment entirely rufescent 2. I'.WONIAK, Srop. 



(4). 5. Second segment laterally or apically black 3. imVADl'M, Cinf. 

 (l). 6. Head abruptly contracted behind the eyes. 



(8). 7. Abdomen centrally red 4. l!I..\NI>li.s, Gniv. 



(7). 8. Abdomen entirely black 5. 1)K1'L.\n.\tus, C7n/7'. 



R 



