69 



althouo-h injury was not then noticeable the insects might do damage 

 tlie following spring. Such a sequel is often to be expected, and it 

 seems probable that many reported instances of injur}' by this and 

 related forms of maggots are due to their habit of developing on 

 decaying- vegetable and other matter and afterwards attacking roots 

 and taproots and other healthy vegetation of the vicinity. Most vege- 

 tables, more particularly beans, peas, and maize, are subject to damage, 

 and cabbage, turnip, radish, onions, and sweet potatoes are also much 

 affected. The insect which is generally distributed in the United 

 States is shown in its different stages in figure 65. It resembles the beet 

 or spinach leaf -miner previously considered. The particularly distin- 

 guishing characteristic of the fly consists of a i;ow of short bristly 

 hairs of nearly equal length on the inside of the posterior tibiae of the 

 male (fig. 64, a). The length of the wing is about one-fifth and of 



Fig. 64. — Pegomya/tisciccjis: a, male fly, dorsal ■saew, />, female, lateral view; e, head of female, from 

 above; d, larva, from side; e. anal segment of larva; /, anal spiracles; jr, thoracic spiracles; /;, pupa- 

 rium — all much enlarged (author's illustration, Division of Entomology). 



the l)od3' about one-sixth of an inch. The maggot as 'Cvell as fly 

 resembles the onion maggot. There is little doubt that this insect is 

 of European origin, and it is certainly increasing in destructiveness 

 in this countr}'. 



Reinedles. — Owing to the difficult}- of destroying subterranean pests 

 and the cost of chemicals for the purpose, such as bisulphid of carbon, 

 we have to depend more upon methods of prevention. One way of 

 deterring the parent flies from depositing their eggs consists in the 

 use of sand soaked in kerosene — a cupful to a bucket of dry sand — 

 which is placed at the base of the plants, along the rows. This also 

 kills young maggots that may attempt to work through the mixture. 



Fertilizers are also useful as deterrents, particularly when employed 

 just before or after a shower has thoroughly wet the ground. They 

 .should be applied as nearly as possible to the roots, and the earth 



