70 BRITISH APHIDES. 



remarkable blind beetles, onisci, and centipedes, wliich 

 are also the known denizens of ants' nests. 



These apterous Aphides may be taken in such 

 situations till late in November, and probably there 

 they hybernate. Aphis radiciiin, Goureau, is referred 

 to Trama by Boisduval. Trama troglodytes is frequent 

 on the high moors in Berwickshire, and mostly located 

 in the nests of Myrmica nihra or Formica fuliginosa. 



Genus XXIY.— DRYOBIUS,* Koch. 

 Knopperlause. Clouded Oak- Aphis. 



Rostrum rather long and thick, projecting beyond 

 the post-sternum. Much longer in the young. 



Antennae slender, six-jointed, with an unciform 

 process on the sixth joint. Third joint more than 

 twice the length of any other. The fourth and fifth 

 joints about equal. The sixth less than half the 

 length of the fifth. 



Cornicles conical, and very short. 



Cauda inconspicuous and rounded. 



Legs, the first two pair moderately long, the hinder 

 pair disproportionately long ; tarsus composed of two 

 distinct joints. 



Wings moderately long in the males, but very short 

 in the viviparous females. Stigmata rather long. 

 Cubital and first furcal veins issue from the same 

 point, which is at some distance from the cubitus. 

 The membrane of the upper wings variegated with 

 brown smoky fasciae. 



* From Spvc, an oak, and /3iow, to live. Prof. Monell warns me that 

 there is an American lepidopterons insect named Dryohius sexfasciatus. 

 I have failed to learn anything definite about this insect, or whether 

 Dryobius can claim priority as a lepidopterons form over that genus as 

 an Aphis. Koch's commenced to publish in 1854. Mr. McLachlan 

 informs me that Dryobus is a coleopterous genus which approximates 

 to the above name. In this uncertainty I retain Koch's nomenclature. 



