52 NEMATUS QUERCUS. 



2. NEMATUS QUERCUS. 

 Plate I, fig. 2, ? ; 2 a c, Trophi ; Plate XY, fig. 2, Saw. 



Nematus quercus, Hart., Blattw., 190, 10; Thorns., Opus., 620, 

 13 ; Hym, Scand., i, 95, 18 ; Br. and 

 Zad., Schr. Ges. Konig., xvi, 61, 

 pi. 6, f. 17; Andre, Species, 103; 

 Cat., 12,* 5. 



Tenthredo lorealis, Zett., Ins. Lap., 353, 53. 



Antennae a little shorter than the body, black, filiform, tapering 

 towards the apex. Head black, shining, covered with greyish 

 pubescence, finely punctured; the clypeus a little rounded at the 

 apex ; the labrum white, palpi pale. Thorax black, shining, finely 

 punctured, covered with short microscopic down ; pleurae smooth and 

 shining; the extreme edge of pronotum and the tegulse pale red. 

 Abdomen clear red ; the basal segment, part of second and the apical 

 three, black ; cerci longish, black, sheath of the saw black, hairy, 

 projecting. Wings very slightly clouded at apex, clear at base ; the 

 costa fuscous, stigma black. Legs: coxae at apex and trochanters 

 white ; the femora reddish testaceous, sometimes with a black line at the 

 base ; a black dot on the apex of intermediate, and a large black line 

 on the apex of posterior ; tibiae pale testaceous, apical half of posterior 

 and the posterior tarsi black ; the four anterior tarsi are pale testaceous ; 

 spurs testaceous, longish, extending to near the middle of the meta- 

 tarsus. 



The $ is extremely rare, and I have never seen it. According to 

 Zaddach it is not unlike the $ in coloration, but the reddish band on 

 the abdomen is narrower, and is interrupted in the middle with black 

 spots. Sometimes the ring is present only on the third and fourth 

 segments ; in other specimens it extends from the second to the fifth, 

 and in this case the second, third, and fifth segments bear, in the middle, 

 a broad black splash, and the fourth two small black spots. The belly 

 is nearly all yellow. 



Length 3 lines. 



The wings are sometimes hyaline; the coxae are 

 often black at the base ; sometimes the posterior tro- 

 chanters and the femora are nearly all black. In one 

 of my Scotch specimens the posterior tibiae are totally 

 black. The amount of the red colour on the abdomen 

 also varies. The first transverse cubital nervure is 

 rarely present. 



From Erichsoni the present species is easily known 

 by its smaller size, thinner, longer, and quite black 

 antennae, whitish labrum, and smooth shining pleurae ; 

 the posterior legs are also darker coloured. 



The larva, according to Brischke, feeds on 



