Insect Pests and Fungoid Diseases. 



417 



ASPARAGUS FLY (Platyparea poeciloptera).This is a small hairy 

 fly, brownish in colour, with lighter bands on the abdomen and brownish 

 bands on the wings. The larva is a yellowish glossy maggot, with a dark 

 head and without legs. The fly lays its eggs from early in April to the 

 middle of July, and the larvae hatch out from two to three weeks later. 

 They at once begin to bore into the tender young shoots, following a down- 

 wardgcourse. The affected shoots become dwarfed and yellowish, and rot 

 at or below the ground line. 



Treatment : Cut out close to the root and burn all affected shoots. In 

 the autumn burn all tops and dig up and burn all dry stumps. 



The flies may be collected in the early morning from the tips of the 

 shoots. Sticks smeared with banding grease or tar and stuck into the bed 

 at intervals will catch numbers of flies as they settle. 



Early in the spring following an attack it would probably serve to check 

 another attack by the fly if the beds were dressed with one of the adver- 

 tised soil fumigants, lightly forked in before the shoots began to grow. 



BEAN APHIS (Aphis fabce). This aphis is popularly known as the 

 "Collier" and "Black Dolphin Fly." Large clusters form at the 

 tops of the broad bean 

 plants, and if allowed to 

 remain, increase at such 

 a rate that the shoots 

 become covered either 

 with the flies or with a 

 sticky excrement which 

 besides making the plants 

 disagreeable to handle 

 interferes with the func- 

 tions of the leaves and 

 prevents any prospect of 

 a profitable crop. 



Treatment : As soon 

 as the aphis is observed 

 on the plants the tips of 

 the shoots where they 

 congregate should be cut off. These should be put in a pail containing 

 a little paraffin and carried away and destroyed ; if they are thrown about 

 on the ground many of the aphis will get on the plants again and much of 

 the labour will be lost. Early-sown plants often escape this pest. 



See under Aphides for washes. 



BEET AND MANGOLD FLY (Pegomyia betce) This fly lays eggs on 

 the leaves of the plants during June and July. Small maggots hatch out 

 and burrow into the leaves, eating the green inner tissues. Blisters and 

 blotches are formed, the leaves shrivel, and the growth of the plant is 

 severely checked. 



Treatment- Dress affected nlnnts with some stimulating manure, such 



27 



Bean Aphis, or Black Dolphin, 



Infested Bean shoot ; 2, Male Aphis, magnified ; 3, Lines 

 showing natural size ; 4, Female Aphis, magnified. 



