266 FOREST ENTOMOLOGY. 



Aphis viburni (Schr.) 



This is another species causing the tip shoots to form into a rough 

 rosette of leaves on ViJmrnum opulus, and the shining blackish insects 

 may be found underneath the leaves. 



Aphis sa.mbuci (Linn.) 



This insect is very plentiful on the young shoots of elder. They 

 are very gregarious, and often cluster two or three deep, and thus 

 form a covering from three to six inches in length on the shoots. 

 There are many species of the genus Aphis on forest trees and 

 shrubs, but they may be all recognised as belonging to this genus 

 from their structure, and in nearly all cases the specific name coincides 



with the name of the host-plant. 

 ^/^ Ileiice the specific name of the 

 in^ect may be almost anticipated; 

 l)ut this species is a migrant, 

 and does not live all the year on 

 older. Fig. 255 is an illustration 

 of the winged female. 



Genus Chaitophorus. 



Fig. 255.-A,.his .sa.uhnci. (From Buckt,>n',s ^^ ^his genUS may be COU- 



sSy'r'^' °^ ^"^'''' Aphides.' Ray founded with Drepanosiphum, it 



is well to give full characters of 

 the same, according to Buckton. Eostrum fairly long ; head with 

 tufted bristles ; antennte much as in Aphis, and short compared with 

 Drepanosiphum, very hairy ; abdomen studded over with tubercles, 

 eacli of which is surmounted with a tuft of bristles ; cornicles 

 very short, and in mounted specimens projected at right angles 

 to the abdomen. Legs comparatively short and hairy. "Wings 

 veined as in Aphis. 



Chaitophorus aceris (Linn.) 



An aphis is found on the sycamore which may be readily con- 

 founded with Drepanosiplium platanoides previously described. This 



