41 



COKN AND GRASS. 



Corn Aphis or Plant Louse. Siphonophora r/ranarm, Kirby ; 

 Aphis avena; (Fab. ?). 



SiPHONOPHOHA GEANAEIA. 



Winged female ; young Aphis, magnified ; and infested Wheat ear ; after Buckton. 



Corn Aphis is only an occasionally serious infestation in this 

 country ; but in 1885 it was exceedingly prevalent, and in last season 

 it was to this attack (and to that of the mildew or rust, often known as 

 blight) that much of the loss on Corn was apparently to be attributed. 



The winged female figured above, magnified, is somewhat more than 

 a quarter of an inch in the spread of the wings ; of a pale brown or rusty 

 yellow, but the thorax brown, with darker lobes above, and the abdomen 

 shining green, with four well-marked black spots on the back, and some 

 black spots on the sides, and the honey-tubes (cornicles) black ; legs yel- 

 low, with black knees and feet. In the early stages the colour is given as 

 (typically) green of some shade. The wingless female, producing living 

 young, is also given as green or brownish green. But though this S. (jra- 

 naria, ^)/^/ay//)/ considered, has much green in its colouring, a very large 

 proportion of the " Wheat Plant Lice " are often of some shade of brown, 

 and much correspond with the Oat Aphis, Aphis avena, of Fabricius.* 



* For description, with colours of "Lice," or early condition ; pui)fi>, that is, 

 when showing wing-cases ; and wniged specimens, see my ' Report on Injurious 

 Insects for 1885,' p. 16, where I give a special note of specimens sent me from Tabley 

 Grange, Cheshire. 



