49 



Several species of predaceous beetles andi bugs are known to feed up- 

 on the caterpillars; and mites have been found destroying the egg-masses. 

 Birds.— Many species of birds feed to a greater or lesser extent up- 

 on the eggs and caterpillars, and undoubtedly assist considerably in re- 

 ducing their numbers. The following have been recorded by various writ- 

 ers as feeding on the caterpillars: Black and yellow billed cuckoos, 

 Baltimore oriole, blue jay, crow, robin, catbird, American redstart, 

 white-fbreasted nuthatch, wood thrush, chewink, black and white creeper, 

 different vireos, flicker, scarlet tanager, yellow-billed sapsucker, bronzed 

 grackle, chipping sparrow, to-whee, English sparrow, chickadee, and ce- 

 dar wax wing. Certain of these also feed upon the eggs, and others to a 

 small degree upon the moths. The protection and encouragement of our 

 native birds would go far to-wards reducing the numbers of many injur- 

 ious insects of orchards, shade trees and forests. 



^" -1 



™4 



i^ 





Egg Masses of Tent Caterpillars on Maple Trees. 1 . Old egg mass. 2. Normal egg masses. 3. 



Diseases. — A bacterial disease at times destroys many of the cater- 

 pillars and effectively aidls in their control. Those affected by this dis- 

 ease often remain attached to the^ bark by a portion of the body. The in- 

 ternal organs are largely reduced 'to a dark-coloured fhiid, which exudes 

 when the skin is broken. 



A second disea.se, fungous in its nature, is sometimes prevalent. The 

 affected caterpillars become dry and rigid, and remain for some time 



