64 MASS. EXPERIMENT STATION BULLETIN 369 



Cultivation alone reduced the number of flies 71 percent and 99 percent in first 

 and second generation experiments respectively, and appears to be worth while 

 when insecticides are not applied. Calcium cyanide dust (1 pound per 100 

 square feet) and carbon disulfide emulsion (1 pint per square foot) were relatively 

 ineffective. 



Control of Plum CurcuHo in Apples. (W. D. Whitcomb, Waltham.) The 

 plum curculio attacked apples at two distinct periods in 1939 and generally caused 

 more damage to fruit than it has for several seasons. In many orchards this insect 

 was the most destructive apple pest of the 3'ear. The first critical period occurred 

 on May 31 and June 1, or about three days after the calyx application. At this 

 time, the curculio caused the greatest damage to varieties such as Gravenstein, 

 Astrachan, and Yellow Transparent, which grow rapidly immediately after blos- 

 soming. The second critical period continued from June 7 to 14 but was less 

 destructive because adequate protection had been applied. 



During the first critical period sprays using lead arsenate 4 pounds, wettable 

 sulfur 4 pounds, and soybean flour 1 pound in each 100 gallons were applied to 

 certain trees June 1, 3, and 6. Just before each application, 50 apples of each 

 variety were measured with calipers to determine the average diameter in six- 

 teenths of an inch. 



On Mcintosh and Wealthy the examination of about 70,000 apples, including 

 drops, indicated that the spray applied on June 3 when the apples were approx- 

 imately 4/16-inch in diameter was more timely and effective than the spray on 

 June 1 when the apples were smaller, or on June 6 when they were larger. 



Biology and Control of the Grape Plume Moth and Grape Cane Girdler. 



(W. D. Whitcomb and W. E. Tomlinson, Jr., Waltham.) The Grape Plume 

 Moth, Oxyptilus periscelidactylus Fitch, was abundant throughout eastern Massa- 

 chusetts, especially Metropolitan Boston, in 1939. Examinations of vines in home 

 vineyards near Waltham showed that 32 to 78 percent of the buds were infested. 



Laboratory studies proved that this insect has one generation annually. The 

 eggs, which have not been reported in literature heretofore, are laid singly, 

 embedded in the pubescence at a crotch or node on old canes. They are laid in 

 late June and early July, and the average number laid by a female moth in cap- 

 tivity was 12.6. Incubation is completed in about four weeks, but the larva 

 remains in the eggshell until the following spring. The larva hatches about 

 May 10 and feeds for about one month. The pupal period averaged 11.6 days 

 and moths emerged during late June and early July, living seven to twelve days 

 in captivity. The photographs on page 50 show some of the stages of the insect, 

 as well as typical injury to vines. 



Dormant sprays applied both in the laboratory and in home vineyards killed 

 the eggs without injury to the vines, and these records are the first known reports 

 of effective control of the grape plume moth with insecticides. The most effective 

 treatments were spraying with sodium dinitro cresylate diluted to 1 and IJ^ 

 percent and with oil emulsion (mayonnaise type) diluted to 3 percent. These 

 sprays applied April 21, which was about two weeks before the larvae hatched, 

 reduced the number of infested tips from 55 percent to 2 and 5 peicent in one 

 experiment, and from 77 percent to 7 and 19 percent in another experiment. 



The results of these studies have been submitted for publication in the Journal 

 of Economic Entomology. 



The Grape Cane Girdlcr, Ampeloglypter ater, Lee, continued to increase in 

 eastern Massachusetts in 1939 and on some of the infested vines 75 percent of 

 the new canes were girdled. 



Life history studies in the insectary showed that there was one generation 

 annually and that the insect hibernates as the adult. E^rly in June when the 



