THE CABBAGE ROOT FLY. 31 



this moth behaving in this manner, and one can therefore only regard 

 it as a change in the feeding habits, which is likely to prove serious 

 to growers of Black Currants. 



It was too late when last year to try the effects of any spraying, 

 but I hope to do so this season. 



THE CHERRY FRUIT MOTH. 



Argyrethesia conjugella. 



Another Tineid pest was reported by a correspondent in Worcester 

 attacking Cherries. It has not previously been met with in the Mid- 

 lands, and it is to be hoped that it will not re-occur this season. 



THE CABBAGE ROOT FLY. 



Pkorbia brassicae, Bouche. 



This is a pest particularly prevalent in the Midland Counties, and, 

 I regret to state, one that is slowly but surely extending itself over a 

 wider area. 



The fly is not unlike the common house-fly in general appearance, 

 though smaller, and with proportionately larger wings. Many of the 

 flies probably hybernate during the winter. 



Early in May the female deposits about fifty eggs, either on the 

 surface of the ground near the plant, or upon the plant stem, and 

 the larvae hatch out in about seven or eight days. 



Washburn 1 gives the following account of egg-laying, as observed 

 by one of his assistants : " When a fly lights on a plant in search 

 of a place to deposit her eggs she runs quickly down the stalk to the 

 ground. Here she searches alternately with her forward or rear end 

 or ovipositor for some crevice or crack through which she can obtain 

 access to the stalk of the plant underground. She acts rather nervously, 

 occasionally running up on to the leaves. The ovipositor is, when ex- 

 tended, nearly as long as the abdomen, very flexible and pointed. With 

 this she tries every place offering any chance of furnishing what she 

 desires. When she has finally found a crevice, she forces the ovipositor 

 in to the limit, and stands still for several seconds, meanwhile usually 

 polishing her head with her fore pair of legs. Then withdraws her 

 ovipositor, and, after climbing on to the plant again, flies with a slow 

 flight near the ground to a point of vantage or to another plant. I 

 watched five flies at work, and they all laid eggs while I was watch- 

 ing them. Only one of them laid more than one egg in a place, and 



Minnesota Univ. Agric. Exp. Stat., Bull. No. 100, 1906. 



