ANNUAL REPORT, 1944-45 29 



Cranberry Spittle Insect {Clastoptera saint-cyri). This insect began to hatch 

 on Cape Cod cranberry bogs as early as May 31, in 1944. 



Arniyworm {Cirphis unipuncta). This worm appeared in numbers on many 

 cranberry bogs from which the winter water was let off as early as May 20 in 

 the spring of 1945. 



New Insecticides. During the 1944 growing season, tests of sabadilla and 

 DDT as possible controls of various cranberry pests were made in cooperation 

 with the United States Bureau of Entomology, with the following results: 



Sabadilla in all cases was used as a 20 percent dust. At the rate of 75 pounds 

 per acre, this dust was fully effective against the black-headed fireworm (Rhopo- 

 bota); and at 100 pounds per acre it controlled the blunt-nosed leafhopper {Ophi- 

 ola) reasonably well. Smaller amounts were not enough. At the rate of 100 

 pounds per acre, it was wholly ineffective as a treatment for the cranberry fruit 

 worm {Mineola), and killed only about two thirds of the cranberry girdler {Cram- 

 hus) moths treated. 



No injury to cranberry vines or blossoms from sabadilla was observed. It 

 was not liked by the growers because of its sternutative effects on those handling 

 it. This seems to be a fair stop-gap insecticide for the black-headed fireworm 

 and blunt-nosed leafhopper, but probably will never have permanent value as a 

 cranberry insecticide. 



DDT. Fifty pounds of 3 percent dust to an acre was fully effective against 

 full - grown gypsy moth caterpillars and the blunt - nosed leafhopper, lesser 

 strengths not being clearly satisfactory. The 5 percent dust at the rate of 100 

 pounds to the acre was 80 percent effective against the cranberry fruit worm, but 

 was clearly less satisfactory than derris or cryolite. The 5 percent dust at the 

 rate of 100 pounds per acre, used after the flight of the moths, killed about 75 

 percent of the small worms of the cranberry girdler on the bog floor. No evidence 

 appeared that DDT is injurous to cranberries at the strengths and in the amounts 

 used. The bee situation is such that it seems dangerous to advocate the use of 

 this material on cranberry bogs even against pests which it controls readily. 



Prevalence of Cranberry Insects. The relative general abundance of cranberry 

 insects in the 1944 season was as follows: 



1. Gypsy moth infestation relatively fairly heavy throughout the cranberry 

 section of southeastern Massachusetts. 



2 Blunt-nosed leafhopper (Ophiola) well controlled and rather scarce every- 

 where on the bogs. 



3 Cranberry fruit worm (Mineola) extremely abundant and destructive 

 everywhere in southeastern Massachusetts except in Bristol County, more so 

 than for many years. It may be worth noting that a similar insect, the codling 

 moth, was also very abundant in New England this year. The fruit worm was 

 not noticeably prevalent on bogs in Middlesex County. 



4. Black-headed fireworm less troublesome than usual. 



5. No firebeetles (Cryptocephalus) found. 



6. Spanworms in general not plentiful. 



7. False armyworm (Xylena) norinal in abundance. 



8. Black cutworms (Euxoa^ ypsilon) very abundant after summer flooding 

 of bogs to control grubs. 



9. Cranberry girdler (Crambus) very plentiful and troublesome, due probably 

 to reduced resanding and fall flooding caused by labor scarcity, a war condition. 



^Essig, Co-lege EntoinoIo.Ty, 1942, p. 476. 



