April, '19] McCOLLOCH: ELEODES OPACA 183 



but this is more difficult and less satisfactory with insect damage by- 

 such as the Hessian fly and joint worm. In the latter cases we can 

 compare with previous years, but we have no basis to estimate accu- 

 rately the injury in individual fields since there is no reliable compari- 

 son between infestation and injury. In the case of the fall injury by 

 Hessian fly, the damage can be estimated only when the infestation is 

 severe and the plants killed outright and in the case of spring injury 

 by fly and by the wheat joint worm we do not know just how much or 

 even the approximate damage by the insects. It is planned to get 

 positive data on these facts another year for the joint worm and Hes- 

 sian fly by enclosing large areas during the oviposition period of the 

 fly and joint worm, two to be kept free from infestation and two to 

 be infested by the introduction of joint worm adults and Hessian fly, 

 respectively. It is to be hoped that others may be in a position to re- 

 peat these experiments and to make similar tests with other insects. 



Continuity of Investigations 



In order to secure reliable results it is important, and in the cases of 

 such insects as the Hessian fly and corn root aphis, absolutely neces- 

 sary, to continue the experiments over a period of years. This is well 

 illustrated in the 1918 Hessian fly sowing experiments. Should we 

 base our conclusions on this single season's results, our recommenda- 

 tion for fall sowing of wheat would be inaccurate since the fly-free date 

 in 1918 was earlier than normal. 



Continuity of observation is also very necessary in assisting the 

 entomologist to predict the likelihood of an insect outbreak a following 

 year and to determine the seriousness of such a possible outbreak. 

 Thus a study of the likely hibernating quarters of the chmch bug in a 

 certain section of the country extending over a comparatively large 

 area and for several consecutive years is necessary to enable the ento- 

 mologist by surveys from fall to fall, to determine with reasonable 

 accuracy, the probabilities of a chinch bug outbreak and the extent 

 and degree of the likely infestation the following season. 



ELEODES OPACA SAY, AN IMPORTANT ENEMY OF WHEAT IN 



THE GREAT PLAINS AREA' 



By Jamks W. McColloch, Associate Entomohujisl, Kansas Slate Agricultural 

 Experiment Stati'yn 



Although the false wireworm, Eleodcs opacn Say, was describeil in 

 1823 (Say, 1823, p. 263) it was not recognized as an insect of economic 



' Contribution from the Entomological Laboratory, Kun.sa.s State Agricultural Col- 

 lege, No. 3.S. This paper einhodies some of the results obtaincii in the prosecution of 

 project No. 100 of the Kansas E.xperiment Station. 



