desired information was obtained, Mr. Stoddard wrote that the pests had 

 largely disappeared, seemingly as a result of the great concentration of 

 birds in the infested area. 



In an address before the National Association of Audubon Societies on 

 October 29 1935, S. A. Rohwer, Assistant Chief of the Bureau of Entomology 

 and Plant Quarantine, said: 



"Examples of the part birds play in the control of insect pests are 

 numerous. More than 40 species of the native wild birds prey on the true 

 army worm, and similar numbers feed on the fall army worm or grass worm of 

 the South. A specialist of the Bureau of Entomology and Plant Quarantine 

 working m the Southeastern States recently recorded numerous observations 

 which_ indicate that woodpeckers feed so extensively on the corn earworm 

 removing the worms from the ears before they have penetrated into the grain, 

 that in certain seasons and localities they give a fair measure of control. 

 in baliiornia another specialist reports that red-winged blackbirds fed so 

 extensively on the valley grasshopper in the Sacramento Valley that the po- 

 tential numbers for 1936 were reduced from 15 to 30 percent." 



Ralph C. Hall, of the Bureau of Entomology and Plant Quarantine, and 

 three assistant research entomologists made a detailed study of the locust 

 borer m the North Central States from 1931 through 1937 and concluded that 

 Woodpeckers arc important predators of the locust borer larvae in that re- 

 gion. In 1937 they were responsible for the removal of 29.4 percent of the 

 spring borer population of the nine-year old Cambridge [Ohio] stand. They 

 also removed about 20 percent of the larval population of two four-year old 

 Cambridge sprout plots. Locust borer survival was reduced by 29 percent in 

 the Cambridge area in 1937 by this predator. This was approximately the same 

 as tor the previous three years in the area." In other areas the birds were 

 much less effective. Dr. Hall added that "Hairy and downy woodpeckers feed 

 heavily upon young larvae in early spring, shortly after inception of s-oring 

 larval activity," and that for four years they "removed arroroximately 30- 

 percent of the active population. In the pre-pupal and pupal stages a cer- 

 tain amount of control is exerted by the feeding of red-headed woodpeckers. . . 

 it is possible that they are even more of a control factor farther south 

 where they are more abundant." He concluded that parasites arc relatively 

 insignificant as a control factor and much less effective than birds. 



The value of birds in controlling the most destructive insect pests of 

 the celery crop in the vicinity of Sanford, Ela., is worthy of note. The 

 economic importance of celery growing in that area is evidenced by the fact 

 that a population of about 20,000 inhabitants depends (directly or indirectly) 

 almost solely on that crop as a moans of livelihood. Approximately one- 

 third of the entire celery crop of the United States is produced on this 

 narrow strip of land bordering Lakes Monroe and Jessup. During the period 

 that the Bureau of Biological Survey and the Bureau of Entomology and Plant 

 (Quarantine were making a cooperative study of the feeding activities of birds 

 in that area, more than 2,200,000 crates of celery were harvested annually 

 in Florida. At least three-fourths of that quantity was produced in the 

 vicinity of Sanford, where it brought the celery growers from $1.25 to 

 $4,25 a crate. 



_ By far the most destructive insect pest that damaged the celery crop 

 during the period of the study was the celery leaf-tier ( Phjyctaenia rubigalis ), 



