Bo Rev. T. A. Marshall's monograph of 



16. Bracon mediator, Nees. 



Bracon mediator, Nees, Mon., i., 69, ? . 

 Braco mediator, Wesm., Nouv. Mem. Ac. Brux., 1838, 

 p. 39, <? . 



Black ; mouth, legs (with coxae), and abdomen, rufo-testaceous ; 

 scutum of 1st segment, and 4 last segments entirely, black ; 

 segment 2 rugulose at tlie base, 3 — 7 smooth ; wings subhyaline, 

 stigma blackish; terebra ? as long as the body. Length, <? 1^ — 2; 

 wings, 3i — 4i : ? 2 — 3 ; wings, 4J — 5f Hn. 



Antennas $ 33-jointed, scarcely shorter than the body ; mandibles 

 and palpi testaceous. On each side of the vertex is a subobsolete 

 nifous spot, often wanting, Metathorax shining, with an inchoate 

 apical carina, from which branch out on either side a few rugo- 

 losities. Second abdominal segment rugulose, except the hind 

 margin ; sometimes there is a small black spot in the middle of 

 the base ; suturiform articulation slightly sinuated ; segments 3 — 5 

 rufo-testaceous, the rest black. 



The (? is similar; antennse 36 — 40-jointed, as long as the body ; 

 segments 2 — 3 rugulose ; 4th black with the base rufo-testaceous, 

 or rufo-testaceous with the sides and apex black ; even the 3d is 

 sometimes black at the apex. 



Described from 18 males and 6 females. The latter 

 vary considerably in size ; one is very large as com- 

 pared with the rest, being 3 lines long, or 5 lines 

 including the terebra ; this is the largest British Bracon 

 I have seen. B.fi(scicoxis,^!Vesiin., is distinguished from 

 this species by being generally smaller, having black 

 coxae, a shorter terebra, &c. 



I am indebted to Bignell for a knowledge of the habits 

 of this species, which is a parasite of Trochilium crabro- 

 niforme, Lewin, feeding on the wood of the sallow. 

 Thirty-three specimens, all males, bred from an osier- 

 stem, two years old, in Yorkshire, were sent to Bignell 

 in June, 1884, by Harwood, of Colchester. They emerged 

 from the 7th to the 12tli of the month. Four of these 

 specimens were sent to me. Some years ago I used to 

 find both sexes commonly in an osier-bed near Aylestone, 

 Leicestershire, now destroyed. Cameron has taken them 

 frequently in Cadder Wilderness near Glasgow ; and 

 Fitch near Maldon. Cocoons brown, of loose texture, 

 filling the cavity occupied by the larva of Sesia ; each 

 cocoon is about 3|- lines in length. 



