ANNUAL REPORT, 1940 45 



These pupae waggle the abdomen very freely when disturbed. They are 

 very much like those of the cranberry rootworm (Rhabdopterus) in habits, 

 size, appearance, and structure and in the distribution and character of all 

 the hairs and spines described above. 



All the Colaspis beetles emerged from the pupal condition between the 

 twentieth and twenty-sixth of June. 



For comparison with the description of the Colaspis grub given above, a 

 description of the full-grown grub of the cranberry rootworm ( Rhabdopterus) 

 is given here: Length, a little over a quarter of an inch. Head light 

 brown, the antennae not nearly reaching the tips of the mandibles. Body 

 whitish without markings; the back and sides scattered over with simple 

 brown hairs noticeable under a lens. Abdomen not noticeably darkened 

 by its contents; the venter covered with a brush of brown hairs, those at 

 the sides in clusters and larger than those across the middle, the latter 

 arranged in transverse lines; the tip with a rounded light brown plate on 

 each side of the anal opening. All the tarsal claws single, simple, slender, 

 and sharply pointed. 



Cryolite has come to stay as a cranberry insecticide. About 17,000 pounds 

 of it were used on Massachusetts bogs during the season with generally 

 satisfactory results. It takes four or five days to effect its kill, but it 

 stops worm feeding on foliage very soon. It will he useful mainly against 

 the fruit worm and as a substitute for lead arsenate where that has 

 been used heretofore late in May. The weevil and the black-headed fire- 

 worm should soon cease to be troublesome where it is used fairly regularly 

 against the gypsy moth and false armyworm. It doesn't seem to control 

 spanworms as well as arsenate of lead. 



Anhydro He.ritol-Cocoanut Oil Fatty Acid Esters. Aqueous dispersions 

 of esters of anhydro hexitols and cocoanut oil fatty acids were tried against 

 the cranberry spittle insect, the black-headed fireworm, and the blunt-nosed 

 leafhopper. They failed to control any of these insects to any noticeable 

 extent even when they were used in such strength that they completely 

 destroyed the cranberry inflorescence. 



Prci'aloicc of Cranberry Pests. The relative general abundance of cran- 

 berry pests in ^Massachusetts in the 1940 season, as judged by general 

 observations and by the opinions of cranberry growers, was as follows: 



1. Gypsy moth in Plymouth County about as abundant as in 1939; 

 quite destructive on the outer Cape, but less so than in 1939. 



2. Blunt-nosed leafhopper about the same as in 1939. 



3. Cranberry fruit worm greatly more abundant than in 1939, more 

 destructive than for many years. 



4. Black-headed fireworm about as usual. 



5. Firebeetle {Cryptocephaliis) very much less prevalent than in the last 

 few seasons, only an occasional specimen being found anywhere. 



6. Spanworms about the same as in 1939. 



7. False armyworm much more generally prevalent than for many 

 years. Blossom worm less abundant than usual. Other cutworms scarce 



8. Cranberry girdler {Crarnbus) and cranberry weevil about as in 1939. 



9. Cranberry spittle insect {Clastoptera) and tipworm (Dasyneura) notice- 

 ably more prevalent than in 1939. 



10. Spotted fireworm {Cacoccia) scattered, but more abundant than usual. 



