24 



wei'e lost in the rows where these substances had been applied than 

 in the untreated check rows, due in part to the injury produced by 

 the materials and in part to the ineffectiveness of the substances 

 against the maggot. Like results were reported where the mix- 

 tures were tried on onions. The use of such oily mixtures, there- 

 fore, is not advised a^-ainst these insects. 



RECOMMENDATIONS. 



The recommendations, then, based on the life hist«:try and habits 

 of the insects, are as follows : By clean culture, prevent as many 

 insects as possible from reaching maturity or from propagating. 

 Clean out the outbuildings, sheds and similar place- during the 

 winter to destroy hibernating adults, and destroy rubbish piles 

 out of doors. Remove infested plants and crop remnants, such as 

 cabbage stumps, just as soon as they are no longer useful, and 

 destroy all cruciferous weeds about the place. Having made the 

 land as clean and free from infestation as possible, plant on ground 

 not infested the previous season, and as far as practicable from 

 any that was infested. Then regulate, as has been already dis- 

 cussed, the time of planting to avoid the deposition of the eggs on 

 or around the plants, fertilize well with quick-acting mineral fer- 

 tilizers, avoiding manures, and plant when feasible an earlier trap 

 crop, which when infested can be carefully removed and destroyed 

 with its maggot contents. In addition, protect the plants and pre- 

 vent the eggs from being laid about them or the maggots from 

 getting to the roots by applying some material or covering on the 

 surface of th.e ground around the stem of the plant. For cabbages 

 and cauliflower the tarred paper discs or bran and glue may be 

 used, or on both the crucifera? and onions the carbolized lime or 

 one of the other materials already considered. In the work o£ 

 11>06 the carbolic acid and lime mixture showed up to the best 

 advantage. "Whatever is used, it must be borne in mind that to 

 insure success the applications must be begun early, and made 

 frequently and thoroughly. Apply immediately after the plants 

 are set or have made their appearance above ground, make the first 

 two applications at five-day intervals, the later ones not more than 

 a week apart, and continue at least a month. 



