FORDA FORMIOARIA. 83 



Genus XXXII.— FORDA,* Heyden. 

 Ant-Aphis. Ameisenlaus. 



Antennas 5 -jointed, the last articulation furnished 

 with a small tubercle or nail. The third joint much 

 the longest. Eyes very small. Abdomen convex. 

 Cornicles none. Tarsus provided with two claws. 

 Winged forms unknown. 



The species of this genus occurs in small scattered 

 companies. They feed on the fine fibres of the roots 

 of various grasses. They very commonly affect the 

 nests of Formica flava. 



Both Kaltenbach and Passerini consider the above- 

 noted tubercle to be a true antennal joint. As it is 

 very small, and is not articulated to the fifth joint, I 

 do not count it such. 



Koch remarks that the young have much resem- 

 blance to Trama. They, however, may be distinguished 

 from such by their more simple antennas and minute 

 eyes. 



The eyes of Trama are rather large than otherwise. 



Forda formioaria, Heyd. Plate CXXVI. 



Bhkoterus vacca, Hartig. 



Forda formicaria, Heyd., Kalt., Koch, Pass. 



Viviparous female* 



Very variable as to size and colour. Large specimens 

 measure — 



Inch. Millimetres. 



Length of body O'lOOxO'060 2-53 X 1*52. 

 Antennse 0-040 1*01. 



* Probably from/ero, which ordinarily makes latus, but irrregularly 

 fordus, pregnant, or prolific ; thus forda vacca, &c. However, this 

 genus is far less productive than most other kinds of Aphides 



