HESPERIIDS AND THECLIDS. 77 



genus, Gorytes, Latr., remarking that thus merged together they 

 are easily distinguished from other Sphegidae by certain char- 

 acters, which he gives. But this union of the genera at once 

 leads him to give some characters to his genus Gorytes which 

 do not apply to it as a whole. Leaving out the question of the 

 differences of neuration which Saunders once considered sufficient 

 for the definition of the three genera, I believe that these are 

 perfectly good and valid on other characters, some of which may 

 be briefly tabulated as follows : 



1 (2). Mesopleural portion of the thorax not separated from the 



mesopectus by a distinct groove or ridge ; front tarsi of 

 9 without a pecten Gorytes. 



2 (1). Mesopleura and mesosternura distinctly separated ; 9 with 



a pecten on the front tarsi. 



3 (4). Posterior ocelli distant from the margin of tlie eyes by a 



space at least hardly less than that between themselves 



HopUsus. 



4 (3). Posterior ocelli much nearer the eye margins than to one 



another Arpactus. 



I believe all the species of these genera, so far as the habits 

 are known, prey on Homoptera, Gorytes and Harpactus on 

 cuckoo-spit insects. The genus Nyssoii, as I have elsewhere 

 recorded, seems certainly to be parasitic on members of these 

 three genera. N. spinosus appears to be attached to Gorytes 

 mystdceas, N. trimaculatus to HopUsus quadrifasciatns, and 

 N. dimidiates to Arpactus tumidus. Of Alysoii [Didineis] I have 

 not been able to observe living specimens. 



Paignton ; 



March 1st, 1919. 



HESPEPJIDS AND THECLIDS. 

 By J. J. Lister, F.R.S., F.E.S. 



My friend Capt. E. N. S. Tebb and 1 made a short excursion 

 last May to beat for the larvte of Hairstreaks and to see the 

 chequered Skipper {Carterocephalas paUemon) in its native haunts. 

 Some account of our doings may, I hope, be of interest to our 

 fellow-entomologists. 



We started from Cambridge on the afternoon of Friday, 

 May 24th, and bicycling from Huntingdon, reached the "Wheat- 

 sheaf" on Alconbury Hill about six. We were able to put in an 

 hour in Monk's Wood beating the sloe-bushes before dinner, and 

 I had the satisfaction of bringing back seven nearly full-grown 

 larvfe of Thecla pruni and three small larvae oi Zephyr as betulce. 

 For the three following days we had much cloud, a north-east 

 wind and a little sunshine; but when beating for larvae one is, 



