b THE CABBAGE MAGGOT. 



We do not understand why other workers failed to obtain 

 this. The same observation was repeated with other speci- 

 mens, the flies laying- within four hours of the time they 

 were confined, and placing their eggs in the axils of the 

 leaves. The egg under both of these jars hatched on July 

 6th, a few hours over three days. 



The Hatching of the Egg. The hatching of one egg was 

 .observed under the microscope. The active larva in this 

 instance tried unsuccessfully for several hours to free itself 

 of the empty shell, and finally died. The smooth surface of 

 the glass slide may have been and probably was the cause of 

 this failure. Later we figured one in the act of hatching, 

 and it would appear that the larva emerges from the egg 

 through the groove above referred to. 



Laboratory Experiments zvith Eggs. May 27th 200 eggs 

 collected and divided into two equal parts, one part treated 

 with carbolic emulsion, i part to 30 parts water, for 30 

 seconds. Later three of the untreated eggs hatched, and five 

 of those immersed in the emulsion. 



Observations on Maggot. May 31st a few maggots ob- 

 served. On June 5th many more were found, \-arying from 

 those just hatched to those nearly and quite full grown. On 

 June 1 2th many had changed to pupae. At this date too, 

 practically all cauliflower with many market gardeners, was 

 found to be ruined by the maggot. The very earliest set 

 cauliflower, of wdiich there was not a large amount, made a 

 better showing than plants set out later. Many of the mag- 

 gots observed early in June (June 5 to 7) were full grown, 

 and by July 7th the majority of the maggots of first brood 

 appeared to have transformed to pupae. ■ 



We cannot speak definitely to a day as to the length of 

 life of the maggot. Some, wdiich were believed to be but a 

 day old when found, required tw^enty days to reach maturity, 

 and transform to pupae, indicating that the larval life may 

 last three weeks. 



Laboratory Experiments on Maggots. Young maggots 

 allowed to remain in carbolic emulsion (i part emulsion and 

 30 of water) w^ere killed in two hours and tw'enty minutes, 

 full grown specimens required three hours and forty minutes 

 before succumbing. Maggots immersed in lime water (2 lbs. 

 slaked in i gal, water) for twenty minutes were killed. 



