50 



ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 47 



the twig to the ground, where transformation occurs. The adult 

 is a rather slender, brown beetle, about three-fourths inch long, 

 that emerges from the pupa. The female lays eggs in twigs in 

 early summer. 



Control Measure 20 (end of circular) . 



Oak Kermes, Kermes pubescens Bogue, fig. 36. — Of most im- 

 portance on bur oak, but sometimes found on chinquapin, white 

 oaks, and red oaks, the oak kermes is closely related to the scale 



Fig. 36. — Oak kermes: an infestation of this almost spherical scalelike 

 insect at the base of a new shoot. 



insects. After wintering on the bark of twigs and branches, the 

 oak kermes migrates to a growing shoot. Where numerous indi- 

 viduals cluster around shoots and on the under sides of the leaves, 

 they distort and kill the new growth. The full-grown female 

 kermes is about one-eighth inch in diameter, almost spherical, 

 light brown in color, and covered with very fine fuzz. The male 

 produces a tiny white cocoon, in which it develops. In the spring, 

 each female lays several hundred light brown eggs under her 

 shell. In June, the reddish-brown crawlers that emerge from 

 the eggs leave the mother shell to find a suitable place for feed- 

 ing. 



Control Measure 5 (end of circular), before the buds swell, 

 to kill the adults; or Control Measure 3, about July 1, to kill the 

 crawlers. 



