INJURIOUS INSECTS OF 1904. 173 



15,000 cabbage plants and 10,000 cauliflower plants, practically his 

 entire crop, through the agency of the cabbage maggot. He states 

 further that the fly worked right through September, and was as 

 bad on late cabbage as on early. The number of cabbage or cauli- 

 flower plants set to an acre is small compared with beans or onions 

 on the same area ; hence, remedies may be applied to cabbage or 

 cauliflower which would not be practical for beans or onions. 

 These flies lay their eggs upon the surface of the ground near the 

 stem, and the maggots, hatching a day or two later, work through 

 the ground to the stem. One means taken to prevent attack con- 

 sists of round discs of the cheaper grades of tarred paper, about 4 

 to 4^ inches in diameter, with a slit cut from the edge to the cen- 

 ter. These are slipped around the stems of the plants, and made 

 to lie flat on the ground. To be effective they must be applied 

 before the eggs are laid. The idea is to keep the fly which lays 

 the eggs away from the stalks where they enter the ground, oblig- 

 ing her if she lays at all, to lay her eggs so far from the plants that 

 the maggots cannot reach them. Onion plants infested by mag- 

 gots, evidenced by the yellowing and wilting of the leaves, should, 

 if weakened beyond all hope of recovery, be pulled and destroyed, 

 that the maggots therein may not develop and spread the mischief. 

 In bad cases weak kerosene emulsion might be employed along the 

 rows, wetting the stalks and adjoining soil. This would, to some 

 extent, if used frequently, repel the fly, and possibly kill some of 

 the larvje which might not be protected. One party claims to have 

 obtained relief by making an application of about a thimbleful of 

 common salt about the root stalk. We have never tried this, but 

 would remind our readers that while a little salt is good for plants 

 it should be used with caution in connection with flowers or most 

 vegetables. Finely ground tobacco, or sOot, or ashes, or air 

 slaked lime, or sand wet with kerosene, a cupful of kerosene to a 

 pail of sand, is sometimes applied around the plants, or along the 

 rows. This must be done before the eggs are laid. When the 

 maggots are working on the stem, kerosene emulsion or carbolic 

 acid emulsion has been used with success. Carbolic acid emulsion 

 is made as follows: Dissolve i lb. hard soap in i gal. boiling 

 water, add i pint crude carbolic acid, and churn through force 

 pump. When wanted for use against cabbage maggots dilute it 



