24 TRICHIOSOMA BETULETI. 



Mesoleius rufus, Gr., have been recorded as parasites. 



The species is parthenogenetic, the virgin eggs pro- 

 ducing males. 



Common in June, especially in Scotland. 



Continental distribution : Sweden, Germany, Holland, 

 France, Russia. 



4. TEIOHIOSOMA BETULETI. 

 Vol. II, PL XII, figs. 11 a and 6, Larva. 



Cimbex betuleti, Klug., Jahrb., 225 ; Yoll., Tijd. Bnt., ii, 64, pi. iii. 

 Trichiosoma tibiale, Ste., 111., vii, 10. 



lucorum, West., Gard. Chron., 1852, 68 ; Thorns., 



Hym. Sc., var. betuleti, i, 24. 



Cimbex cratsegi, Br. and Zad., Schr. Ges. Konig., iii, 263. 

 Trichiosoma betuleti, Cam., Proc. N. H. S. Glas., iii, 207 ; Fauna, 



46, 3 ; Andre, Species, i, 27 ; Cat., 2,* 2. 



Black; tarsi yellowish, tibia3 fuscous; head, thorax, and abdomen 

 covered densely with reddish-yellow hairs. Abdomen from the basal 

 third covered uniformly with black, sometimes pale, hairs, which are 

 shorter than those on the base and thorax. 



Length 6 9 lines. 



Apart from the fuscous-coloured tibiae, which sepa- 

 rates it readily from the three other British species, 

 betuleti differs from lucorum (of which it is considered a 

 variety by Thomson) by the reddish hair on the thorax 

 and abdomen, and by the latter being not uniformly 

 covered with hair of the same length. 



The larva, when young, is green, but this colour is 

 usually hid by the white exudation ; the head black, 

 also covered by a white powder. The oral region is 

 white. 



When old the larva is bright greenish-yellow, with a 

 darker green line running down the back. The head 

 is yellowish, with a large brownish-orange mark on the 

 vertex. The legs pale whitish-green, with brown claws ; 

 the spiracles reddish. The skin is covered with minute 

 warts (much smaller than the tubercles found on the 

 other species), and is sparsely covered over with a 

 white powder. 



