TENTHREDO MESOMELA. 147 



posed of three, the second of four warts ; the lateral 

 folds over the legs bear also warts. The stigmas are 

 light brown. Head shortly haired, the front and 

 vertex opaque, marked with blackish points extending 

 from the eyes to the base of the antennae. Between 

 the eyes is a brownish splash. The anal fold is vel- 

 vety pilose ; the claws are light brown. It feeds in 

 July. 



Tenthredo mandibulars (Vol. I, p. 89). 



Brischke. describes the larva (1. c, p. 113, Taf. vii, 

 fig. 11). It is 22 mm. long, transversely wrinkled, 

 and shortly pilose. The ground colour is a bright 

 grey, the back to the orange-coloured stigmas deep 

 black. Each segment bears laterally a longish orange- 

 yellow spot, the second and third segments having in 

 addition in front an orange splash ; the first segment 

 has none. On the ground colour are small black spots, 

 mostly three on each segment. The head is shining 

 black, the lower half reddish-brown. 



At the last moult the larva seems shorter, more 

 cylindrical, shining blackish-brown ; the ventral surface 

 and legs grey; the orange- coloured spots are darker. 



The food-plants are Petasites officinalis and Tussi- 

 lago farfara, on which it is found from August to 

 October. 



Tenthredo hesomela (Yol. I, p. 93). 



Konow (D. E. Z., 1890, 254) sinks obsoleta, Klug, 

 and arctica, Thorns., as varieties of this species. 

 Brischke (1. c, 112, pi. vii, fig. 10) describes the larva, 

 and his description differs from mine. The food-plants 

 he gives as Polygonum persicaria and Arctium lappa. 

 The colour of the larva is given as bright ash-green, 

 and it is shortly and finely pilose. The back is dark 

 brownish-grey, with some darker markings. On each 



