No. 4.] INSECTS AND GARDEN CROPS. 333 



on the roots of the young plants. These eggs are smooth, 

 white, and large enough to be seen by the eye. Upon hatch- 

 ing, the little maggots they produce burrow into the stem, 

 root or bulb of the plant, often causing a serious amount of 

 damage. After feeding until full grown, the maggots leave 

 the plant and become quiet pupte for a time, after which 

 the adult flies escape from them to lay eggs for another 

 brood, of which there are two and perhaps more each year 

 of the kinds here considered. 



Treatment, 



Many methods have been suggested for checking the rav- 

 ages of these pests, but only a few are of any value. Pro- 

 tection from the cabbage root maggot may be ol)tained by the 

 use of tar paper cut to encircle the stems of the plants when 

 these are set out, but the cost of preparing and apjilying the 

 pieces reduces the vakie of this method. Before the appear- 

 ance of the maggots the use of carbolic acid emulsion has 

 been strongly recommended. To prepare this, a pound of 

 hard soap or a quart of soft soap should be dissolved in a 

 gallon of boiling water. Into this pour a pint of crude 

 carbolic acid, and stir until an emulsion is thoroughly formed. 

 To treat the plants, one quart of this, mixed with about thirty 

 quarts of water, will give the required strength. In apply- 

 ing this emulsion, begin the day after the plants have been 

 set out, or, if raised from seed, a day or two before they 

 come up, thoroughly moistening the ground close to each 

 pUmt with it, and particularly the stems just l)elow the level 

 of the ground, in the case of plants which have been set out. 

 The object of this is to kill every e^^g and maggot present b}^ 

 actual contact with the emulsion. This treatment should be 

 repeated every week or ten days till about the first of June. 

 " Whoever has tried this emulsion thoroughly, reports suc- 

 cess" (Slingerland). 



Another and a})parently equally successful treatment is by 

 the use of carbon disulphide. To apply this properly, an 

 apparatus such as the ISIcGowan injector is necessary. In 

 using this, push the tip of the injector into the ground three 

 or four inches away from the plant, and run it obliquely down 

 to a point just below the roots ; then force al)out a teaspoon- 

 ful of the carbon disulphide out of the injector into the 



