THE WHEAT APHIS. 41 



CHAPTER XLIV. 



THE WHEAT APHIS. 



(^Siphonop flora sp.) 



Order : Hemiptera. Sub-order : Homoptera. Family : Aphididoe. 



This pest of the farmer is one, perhaps, that gives more 

 trouble tliaii many of his other insect enemies. In appear- 

 ance the fully grown insect is about the tenth of an inch 

 long, with the body flattened and widest behind. (See 

 Fig. II.) Each bears a pair of slender feelers {antennae)^ 

 a jointed rostrum or beak, which is folded close against 

 the under side of the body when not in use, three pairs of 

 jointed legs, and towards the hind end of the abdomen 

 are two short tubes (cornicles), the use of which are 

 described in Part 11. , with open extremities. Colour, 

 pale green, varying to brown and often black. A series 

 of small spots, as shown in our figure, are ranged along 

 each side of the abdomen. Regarding the life history of 

 this pest but little is known here. It is, however, well 

 known that the insects are particularly severe on cereals, 

 as wheat, oats, barley, grass, &c., but is especially bad on 

 wheat. According to the best authorities, this Aphid 

 lives through the winter on the old roots in the ground, 

 as do many of the insects of the same group. Professor 

 Garman and others state that the common Wheat Aphis, 

 S. Avenae^ which is closely related if not identical with 

 our own kind, lives on the roots and down in the ground 

 on the stems of winter wheat, and that it also occurs 

 through late summer and early fall on volunteer grain, 

 these facts having been fully ascertained by American 

 investigators ; l)ut Mr. Bruner states that just where the 

 true sexes, male and female, are matured, and where the 



