THE CABBAGE MAGGOT 



HOST PLANTS 



The cabbage maggot feeds on all members of the mustard family, Cruciferae. 

 Metcalf and Flint (8) and Chittenden (3) report that it has been found feeding 

 on celery and beets but this has not been observed in Massachusetts. 



Among the common garden vegetables cabbage, cauliflower, and radish are 

 frequently damaged extensively and seriously, while in some localities fall tur- 

 nips have been severely attacked. When cabbage and cauliflower are grown In 

 the same field., the cauliflower is usually damaged more severely. At Waltham, 

 in 1939, Chinese cabbage, collards, and kohlrabi were infested about as heavily 

 as cabbage but this is apparently unusual. 



The extent of injury to different host plants which have been grown at Wal- 

 tham is shown in Table 1. 



Susceptibility of Cabbage Varieties 



Cabbage varieties show some variation in susceptibility to injury by the 

 cabbage maggot. Brittain (1) in Nova Scotia reported complete immunity for 

 the large Red Drumhead variety, and Glasgow (5) in New York showed a definite 

 resistance for the Danish Ballhead as compared to the Copenhagen Market 

 variety. 



During 1942 and 1943, at Waltham, thirteen varieties of cabbage were observed 

 for susceptibility to injury, as shown in Table 2. 



Table 2. Susceptibility of Cabbage Varieties to Injury by the 

 Cabbage jMaggot. Waltham, Massachusetts, 1942-1943. 



Percent of Percent of Percent of 



Plants Com- ' Salable^ Unsalable^ 



Variety Seasonal^ mercially Heads Heads 

 Maturity Injured 



1942 1943 1942 1943 1942 1943 



Early Jersey Wakefield .. Early , 17.3 13.3 62.7 95.6 37.3 4.2 



Penn State Ballhead Late 30.1 35.5 53.3 71.1 46.7 28.9 



Glory of Enkhuizen Intermediate 37.3 — 49.3 — 507 — 



Allhead Early :. Intermediate 38.7 68.9 74.7 66.7 25.3 33.3 



Red Acre Intermediate 41.3 46.7 52.0 68.9 48.0 31.1 



Mammoth Red Rock Late 48.0 44.4 41.3 62.3 58.7 37.7 



Cornell Early Savoy Early 49.3 48.9 60.3 61.4 39.7 38.6 



Red Drumhead Late 58.7 — 40.0 — 60.0 — 



Premium Flat Dutch Late 58.7 — 52.0 — 48.0 — 



Golden Acre Early 58.7 76.7 33.3 45.6 66.7 54.5 



Marion Market Early 60.0 — 33.3 — 66.7 — 



Copenhagen Market .... Early 77.3 — 13.3 — 86.7 — 



Supercurled Savoy Intermediate 74.7 — 22.7 — 77.3 — 



' Classification of most varieties was taken from Morrison, Drewes and Coulter, Mich. Agr. 

 Expt. Sta. Spec. Bui 249, 1934. 



-Salable heads include those which were classified as Very Large, Large, and Medium at the 

 time they were examined. 



^Unsalable heads include those which were classified as Small, Very Small, Blind, or Dead at 

 the time they were examined. Some of the Small heads might grow to salable size, but they were 

 not salable when classified. The classification of injury and head size was made on different plants 

 and there is, therefore, no direct correlation between the corresponding percentages. 



