1S93.I ■ 175 



DICHRORAMPRA ALPESTRANA, H.-S., AN ADDITION TO THE 



BEITISH LIST. 



BY A. THURNALL. 



On the evening of June 2'2nd, 1892, I captured in Epping Porest 

 a fine specimen of Argyrotoxa Audouinana ; this being a species much 

 wanted, I visited the spot again on the 26th, but after beating for 

 some time, I gave it up in disgust, and turned my attention to the 

 rough herbage growing in an open marshy spot, and was soon rewarded 

 by the capture of a small Dichrorampha, which I at once saw was new 

 to our list. In the course of half an hour I captured about a dozen, 

 most of them worn, sitting upon the stems of Juncus glomeratus and 

 Aira ccespitosa. From observations made at the time I felt sure that 

 the larva would be found feeding on the roots of the '' sneezewort " 

 {AcMlloBa ptarmica , Linn.), and accordingly paid a visit to the spot on 

 March 11th last, soon after the present dry season had set in, and 

 speedily found my surmise correct. The half-dozen larvae dug up on 

 that occasion were very snugly hidden away in neat little cocoons 

 attached to the bark of the roots of the above-named plant, and may 

 be very briefly described as — bone-white with light brown heads. 

 They appeared to have been feeding in and upon the rather long 

 underground suckers, often four or five inches below the surface, much 

 in the same way as Halonota trigeminana larvae feed on the roots of 

 Senecio. They must have an exceedingly moist time of it, as the spot 

 where they occur is over one's shoe tops in semi-liquid clay for months 

 at a time ! They changed to pupse very early in May, and on the 29th 

 a fine ? emerged. 



I found, on paying a visit to the spot on June 4th, that the imagos 

 were well out. From their small size and dull colours they are very 

 diflBcult to see, and I found the best plan was to search the stems of 

 Juncus and Aira, which are generally to be found wherever the food- 

 plant grows : they run up the stems to expand and dry their wings 

 just as D. alpinana does on the stems of tansy. The plants must not 

 be shaken when searching, as on the least alarm they dive down and 

 are lost in the herbage. Doubtless the insect will turn up in many 

 places w^here its food-plant occurs. I am indebted to Lord Walsingham 

 (through Mr. E. Baukes) for the name. 



The following is a brief description of the imago : — 



Head and thorax dark fuscous. Basal half of anterior wings very dark brown, 



the apical half very tliickly irrorated with dark orange scales, an angulated blue 



line leaves the costa bej'ond the middle, reaching to the dorsal margin, or vei-y nearly 



so. Still nearer tlie apex is a short blue line, whicli has, as a sort of continuation 



Q 2 



