100 BRITISH APHIDES. 



Winged viviparous female. 



Inch. Millimetres. 



Expanse of wings 0'310 7"87. 



Size of body 0-080 X 0-035 2-02 X 0-88. 



Length of antenna 0-060 1-52. 



cornicles 0-020 0-50. 



Wholly black. Head and thorax stout. Eyes red- 

 dish. Abdomen carinated and ringed. Legs black, 

 except the femora, which are ferruginous. Wings 

 rather coarse. Stigma grey and veins black. 



During the months of June and July very numerous 

 nn the soft stalks of the elder-tree, Samhucus nigra. 

 They form thick slaty-black encrustations, which are 

 composed of apterous and winged females, interspersed 

 with young and pupee, and packed so close together 

 that the elder-stalks often cannot be distinguished. 

 These swarms are largely visited by ants, eight or ten 

 of which may be seen on every twig of three or four 

 inches length, coursing backwards and forwards over 

 the backs of the Aphides, and watching for the clear 

 drops of sweet secretion which exude from both the 

 anus and the nectaries. 



The ants sometimes drum with their antennae on 

 the sides of the Aphides, which answer this solicitous 

 action by yielding up their sweets. If no ants are at 

 hand to remove the liquid, the Aphides violently expel 

 the drops to a considerable distance, and thus they 

 bedew the surfaces of the leaves below. 



The relations between the ants and Aphides are so 

 remarkable that a sketch of what Huber and others 

 have observed will be inserted in the next volume of 

 this Monograph, where we shall treat of those special 

 Aphides which, up to the present time, have nowhere 

 been found otherwise than imprisoned in ants' nests. 

 On Plate LXX will be found a representation of an ant 

 taking the honey-dew from Apliis sambiicaria. It is 

 remarkable (and no explanation can at present be 

 given) that A. samhuci does not occur in the autumn, 

 and A. samhucayia does not occur in summer. 



