New York Agricultural Experiment Station. 407 



life history of cabbage maggot with reference to 

 growth of early cabbage. 



In the latitude of Geneva the adults of the cabbage maggot appear 

 about May 15 during normal seasons, and the eggs of this species 

 usually occur in large numbers about the roots of cabbage and 

 other cruciferous plants from May 20 to June 5. The work of 

 the maggot is most conspicuous during the last two weeks in June. 

 The time of appearance of the adults and the period of egg laying- 

 are hastened by warm weather during April and May. In order 

 to secure the highest prices early cabbage should ordinarily be 

 ready for market in July. For this reason it is necessary to trans- 

 plant the seedlings from the greenhouse or cold frame in the latter 

 part of April or early in May. During the three or four weeks 

 following the planting in the field, cabbages are most susceptible 

 to injury by this insect. The accompanying chart shows clearly 

 the life history of the pest with reference to the growing of early 

 cabbage. It should be noted that the maggots are most numerous 

 when the plants are small, and therefore most vulnerable to attack. 



STATION EXPERIMENTS IN PROTECTING EARLY 



CABBAGE. 



Many methods have been proposed for the protection of early 

 cabbage from the cabbage maggot. In a series of preliminary 

 tests carbolic-acid emulsion and tar pads proved to be the most 

 effective of the various protective and remedial measures commonly 

 recommended for the control of this pest. In order to ascertain 

 their applicability to the needs of market gardeners and truckers 

 in this State, both of these have been tested in the laboratory and 

 in a number of cooperative field experiments which are briefly 

 described under the headings (l) Tests with Carbolic Acid Emulsion 

 and (2) Tests with Tar Pads. 



TESTS WITH CARBOLIC-ACID EMULSION. 



References to use of carbolic acid for the control of root maggots. — 

 An emulsion of carbolic acid of 0.1 per ct. strength was used by 

 Cook 1 as a remedy for the cabbage maggot in 1881. He reports that 

 frequent ap plications with this diluted material protected radishes 



1 Can. Ent. 13: 189. 



