TETRANEUEA ULMI. 181 



Genus XXYII.— TETRANEUEA,* Hartig. 

 Gallenlatts. 



Rostrum in the adults very short. 



Antennas short, about equal to the head and thorax ; 

 six-jointed, the last joint ending with the usual button ; 

 the third joint much ringed. 



Cornicles and tail entirely wanting. 



Wings similar to those of PempJiigus, except that 

 there is only one oblique vein in the hinder wing. 



The stigma has a dark included spot. 



Legs short, as in Pemphigus. 



These insects live in small pedunculated pseudo- 

 galls, which are usually constructed from the midrib 

 of the Elm leaf. The mature insects perforate the side 

 of the gall, which expands into a more or less irre- 

 gular hole from which they find an exit. 



There is but one British species belonging to this 

 genus as yet recorded. M. Lichtenstein, however, sent 

 me deep-red, hairy galls from the leaves of the Elm, 

 which differed much from those made by the English 

 insect. He jDroposes to call the French insects Tetra- 

 neura rubra. Tetraneura alba also is a Continental 

 species, which has not been observed in England. 



Tetraneura ulmi, Dp, Geer. Plate CXIY, figs. 5 — 13. 



ApJiis gallarum uhni, De Geer, Geoff., Yon Gleichen. 

 Tetraneura ulmi, Hartig, Kalt., Koch., Pass. 



Apterous viviparous female. Queen Aphis. 



Incli. Millimetres. 



Size of body 0-085X0-055 2-14xl-39. 



Length of antennee 0'012 0"30. 



* From rerpa {pro rirapa), four, and vtvpov, a nei've. 



