98 TENTHREDO VIRIDIS. 



An aberration is sometimes seen with the abdomen 

 entirely green. 



Not unlike T. picta, but much larger ; the mark on 

 the vertex is much smaller and distinctly separated ; 

 the green marks on the mesonotum are larger ; there 

 is a pair in front of the scutellum and behind it which 

 are not found in picta ; the black band on the abdomen 

 is narrower, there is no black on sternum, the tarsal 

 joints are only annulated with black; and the radial 

 nervure is always received not far from the middle of 

 the third cellule, never interstitial. 



One of our commonest species, appearing in June 

 and July; often met with on Umlelliferce, which they 

 frequent more for the purpose of killing other insects 

 than to eat the pollen. 



The larva is described by Stein as having a dirty 

 olive-green body, varied with a series of darker or 

 clearer spots, and bearing on each segment two trans- 

 verse series of tubercles ; the head is greyish-green, 

 obscured with black, and pilose. It lives from 

 August to October on the leaves of sundry willows 

 (Salix alba, vitellina, &c.), eating from the edge of the 

 leaf to the midrib, and only during the night. It 

 pupates in the earth. Dours (Cat., 23) says that it 

 feeds also on birch. 



Viridis is probably one of the widest distributed 

 species in the genus, being found all over the Palee- 

 arctic region including Japan. 



06s. Thomson (1. c.) separates T. viridis, L., from T. scalaris, Klug, 

 by the greater extension of the black colour on the vertex, mesonotum 

 and dorsum of abdomen, by its shorter antennae, less developed patellae, 

 and by the suture of meso-pleurse being lined with black. I have never 

 been able to distinguish two forms, and thought at one time (as did 

 also van Vollenhoven) that Thomson's viridis was picta> Klug, but he 

 gives the same size to viridis as scalaris, while the latter is a couple of 

 lines larger. In the Linnean Collection viridis is represented by two 

 specimens^ a ? picta and a $ scalaris. 



