BRITISH ICHNEUMONS. QQ 



lighter or darker red ; $ with sixth and seventh dorsally white, S rarely with 

 latter pale ; post-petiole broad, closely punctate ; second segment with 

 basal incisure deep ; gastrocaeli small, especially in $ , but distinct. I^egs 

 black, femora stout, those of 3 more or less red ; tibiae and tarsi in part 

 red ; front tibiae laterally flavous or whitish and shortly spinulose ; hind 

 coxae shining, sparingly punctate and not scopuliferous. Wings a little 

 clouded ; stigma and tegulae piceous or ferrugineous, latter in S white- 

 dotted ; areolet narrowed above ; external radial nervure apically curved. 

 Length, 8~[o mm. 



I follow most authors in considering /. derivator, Wesm., a mere black- 

 scutellum variety of the female ; but Thomson not only points out in the 

 "Annates" that it is smaller, at most 8 mm., with the frons more thickly 

 punctate, legs more slender, tarsal claws longer and the oral costa dentately 

 elevated, but in his " Opusc. Ent." he includes it definitely in Barich- 

 neurnofi, while placing /. bilurmlatus tentatively next to it, as doubtfully 

 referable to this sub-genus, on account of the tibial formation. If there 

 be two species, they are not understood in Britain, and since the true 

 /. bilumilaUis of Gravenhorst has never been found in Sweden, where 

 Holmgren says /. derivator is only " minus frequens ... in graminosis et 

 fruticetis," both probably do not occur here. 



Like the preceding species, B. derivator may be known by the short 

 antennae being inserted low on the forehead, and the second flagellar joint 

 being sub-transverse, but is distinguished from it by the clearly inflexed 

 genal costa, which is more dentately elevated, as well as by its shorter 

 areola, much larger gastrocaeli, and by the colour of the front tibiae. 



The colour of the male is somewhat inconstant in curious directions ; 

 thus the antennae will at times bear vestiges of a white band, the post- 

 petiole have an apical white dot on either side, or even the seventh seg- 

 ment with a white dorsal dot ; the hind femora are sometimes red. 



Var. triplax. Berth., is a male with white-banded antennae, thescutellum 

 black, and the seventh segment white-marked. The variety procerus, 

 Grav., though normal in other respects, has the front tibiae ferrugineou":, 

 thus agreeing with B. dtrogator. 



Stephens records this species, " scutellum white at the apex," as un- 

 common, about July, near London, and the var. procerus, thence very 

 rarely in June. Bridgman says /. bilunulatus is common in Norfolk, and 

 Bignell took it at Bickleigh, in Devon, on August 20th. It has been 

 frequently bred on the Continent from Trachea piniperda, and also from 

 Orgyia pudibunda, Hadefia adusta and H. baltica ; the var. derivator has 

 emerged from Fidotiia piniaria. 



18. vestigator, IJ'esm. 



Ichneumon deceptor, Gr. Mem. Ac. Sc. Torin, 1820, p. 30S (p.irt) ; I. E. i. 332 ; 

 Ste. Ill M. vii. 170, e.xcl. 9 et indivv. : antennae subtus albcj et stigniate fusco aut 

 piceo ; cf. Wesm. M6m. coiiron. Ac. Belg. 1859, p. 39 ; I'erth. Ann. Soc Fr 1S95, 

 p 244, (J 9 • /• snavis, var. I, Gr. I. E. i. 34S, 9. / vestigator,'^ Wesm. Nouv, 

 Mem. Ac. Brux. 1844, P- 9°; Holm. Ichn. Siiec. i. 175 ; Thorns Ann. Soc. Fr. 1SS8, 

 p. 109 i 9 • Barichneumoii vestigator, Tlioms. O. E -xviii. 1962, i 9 • 



A dull red and black species, with white scutellum and anus. Head 



1 Since Gravenhorst obviously gathered the females of more than one species under his /. 

 deceptor, and his description is not intelligible, it is certainly preferable to retain the very lucid one 

 of Wesniael, which embraces both sexes. 



