G 



COKN AND GRASS. 



and it throws the sap to the lower pods, which are benefited. If, 

 however, the infestation has been allowed to establish itself, the above 

 treatment would very likely be impossible. In the case of the plants 

 (mentioned p. 5) sent me from the Carse of Stirling, it would only 

 have saved one. The others were too far gone, from the black Aphides 

 having spread down the stem, and also from consequent damage, both 

 to the health and the vigour of the plant. 



If the infested part is removed, this and the Aphides on it must be 

 carefully destroyed, or many of these " Colliers " will almost certainly 

 get back to the plants, so that new attack will be started. 



In field growth there does not appear to be any remedy excepting 

 nipping off the tops of the shoots ; but in garden cultivation, good 

 washings with soft-soap mixtures (or even with water alone), sent as 

 hard at the infested shoots as is safely possible, so as to knock some of 

 the plant lice off, and to clean down the leafage from the stickiness and 

 filth, are sure to do good in this way. Also the watering helps on 

 growth, a very important matter, as Aphides multiply most rapidly on 

 plants which are stunted by drought or other causes. 



CORN AND GRASS. 



Gout Fly ; Ribbon-footed Corn Fly. Cklorops urnidpus Meigen. 



Chloeops t.eniopus.* — Gout Fly, grub and pupa ; nat. size and magnified ; with 

 infested stem. 7, 8, 9 and 10, Parasite Flies ; nat. size and magnified. 



* The attack is caused (as mentioned in previous Eeports) by the small black 

 and yellow fly, figured above. She lays an egg on the Barley sheath, the maggot 

 from this attacks the ear, and then eats a channel down one side of the stem to the 

 first knot, and then turns to chrysalis state within the leaves. 



