284 



BRITISH ICHNEUMONS. \Gambrus. 



coxae, the petiolar caiinae extending beyond the spiracles, dull central 

 segments; black $ hind tarsi, white-marked pronotiim, narrower abdomen, 

 and nearly linear basal segment ; and from the remainder of the Conti- 

 nental species in its smaller areolct, the apical white fascia on segments 

 seven and eight of the feniale's abdomen ; the red $ femora and tibiae, of 

 which the hind ones are not broadly black-marked, the apex of its 

 scntellum and its anus more or less broadly, white. 



This species is given in the last British catalogue as synonymous with 

 the following, but, as I pointed out in my paper read before the Entomo- 

 logical Society on March 6th, 1901, it is now universally accepted as 

 distinct, and is here so treated. 



Its distribution extends throughout Europe, and it has several times 

 been bred in Britain from Shnyra venosa by Eedle, Harwood, Marshall 

 and Bignell. It is probably to this species that Kaye refers (Ent. Rec. 

 1899, p. 235) when he writes, "The extraordinary scarcity o'i Arsiloiiclie 

 venosa in ^Vicken now, after having been so abundant in 1895, '•'' attribu- 

 table, one is inclined to think, to the parasitic hymenoptera which attack 

 this species having got in the ascendancy. In the year quoted, when 

 larvae were so abundant, not more than seven or eight per cent, produced 

 moths. Since that time the species has got scarcer and scarcer, until now, 

 when there are actual doubts as to whether the insect is going to maintain 

 itself at Wicken." He adds that it is easy to tell if the larva be parasitized, 

 since, in that case, it never attains the pupal condition. It has also been 

 bred from Poecilocampa populi, Trichiosoina lucorum and a species of 

 Leiicatiia, according to Parfitt's Devon List ; and from Plusia chrysiiis, 

 according to Billups in the Proc. S. Lond. Soc. 1896. 



2. ornatus, Grav. 



Cryptits ornatus, Gr. I. E. ii. 620 ; Ste. 111. M. vii. 293, ? ; Holmgr. Sv. Ak. Handi, 

 1854, p. 53 ; Tschek, Verb. z.-b. Ges. 1872, p. 249 6 'i . C. tricolor, Tasch. Zeits. Ges. 

 Nat. 1865, p. 100, ? (part). Spilocryptus ornatus. Thorns. O. E. v. 506, {, 'i ; cf. 

 Gainbrus ornatus, Thoms. lih. cit. xxi. 2374. 



Head immaculate ; maxillary palpi of $ broadly white centrally. 

 Antennae of 9 with flagellum centrally white-banded and basally rufes- 

 cent. Thorax immaculate, narrower in $. Scutellum black. Abdomen 

 red, of $ sub-linear, of ? somewhat broad, with segments four, five, and 

 generally base of first, black ; c^ with whole of first and part of two to four 

 infuscate ; six and seven broadly white in both sexes ; petiole gradually 

 dilated, with no dorsal carinae ; terebra about half length of abdomen ; 

 ventral valvulae of $ short vomeriform and slightly excised apically. 

 Legs red ; front coxae and trochanters, hind ones with apices of femora 

 and tibiae, black ; $ with hind tibiae also infuscate before the base, or 

 externally entirely obscure with rufescent band before base ; front tibiae 

 not inflated ; $ hind tarsi with joints three and four white. Wings some- 

 what clouded ; radix dark stramineous, tegulae black ; areolet quite 

 parallel-sided. Length, 7-10 mm. 



This species is rendered distinct by its parallel-sided areolet, the 

 gradually dilated petiole of the $ which bears no carinae, and by the 

 structure of the $ ventral valvulae. Moreover, the ? has the head dull 

 behind the eyes, but the cheeks nitidulous, its front coxae and trochanters 



