154 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



bugs,' the grubs hatching from the eggs feeding internally on the 

 bug and destroying it (Figs. 115, 116). Other natural enemies are 

 the Iarva3 of certain predaceous flies, and the larva? and adults of 

 lady-beetles. The little wasp-like parasite first mentioned, how- 

 eve^ is the one that keeps the ' green bug ' in control in normal 

 years, and in years when the latter is most abundant finally over- 

 comes it, as was the case in 1907 in Kansas, North Carolina, and 

 other States in the more northern part of the range of the pest." 



FlG. 113. Lysiphlebus testaceipes Cress., adult female and antenna of male 

 greatly enlarged. (After Webster, U. S. Dept. Agr.) 



"Unfortunately this parasitic wasp as with the other bene- 

 ficial insects is active only while the temperature is above 56 F., 

 or at least 10 above that at which the ' green bug ' breeds freely; 

 and herein is the whole secret of the irregular disastrous outbreaks 

 of the ' green bug ' in grain fields. As accounting for the out- 

 break in the year 1907, the ' green bug ' had had a whole winter 

 and the following late spring in which to breed and multiply un- 

 molested, and it accomplished its principal damage, as in Texas 

 and southern Oklahoma, before the weather was warm enough 

 for the parasite to increase sufficiently to overcome it." 



