94 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



A paper was presented, as follows : 



THE MAPLE LEAF STEM-BORER. 



(Priophorus acericauJis MacG.) 

 By W. E. Britton, New Haven, Conn. 

 [Withdrawn for publication elsewhere.] 

 The following paper was read : 



THE VALUE OF PARASITES IN CEREAL AND FORAGE CROP 



PRODUCTION. 



By F. M. Webster, Washington, D. C. 



While there has been much said of late concerning the beneficial 

 influences of parasites in affecting insect pests of the orchard, garden, 

 and truck farm, we hear little of this in relation to such as attack grain 

 and forage crops. It might almost be said that the average farmer, 

 from his point of idew, sees only the benefits derived by the fruit 

 grower, while the aid that he himself receives from the good offices of 

 parasites is quite outside his vision. The facts are, however, almost 

 if not quite the reverse, and it is probable that the crops of the 

 average farmer are more continually under the protection of, and 

 greater losses are prevented by, beneficial insects than in any other 

 field of husbandry. The real difference is that in the case of the 

 farmer they are obscured or overlooked ; while among the fruits and' 

 vegetables, where observation is less difficult, much more that tran- 

 spires is seen and recorded in reports, bulletins, and the agricultural 

 press. A case in point from my own observation many years ago will 

 serve as an illustration. 



There was a threatened outbreak of wheat midge (Contarinia 

 tritici Kir by) in a field of wheat, the larva? at the usual season being 

 excessively abundant. During late afternoons and early forenoons 

 the heads of wheat were visited by great numbers of predaceous 

 insects that hunted about among the bracts, and greedily devoured the 

 larvae of the midge. Day after day this was observed, until it seemed 

 to me that none of the victims could have-escaped capture. Gradually 

 and naturally the heads changed from green to golden, and the threat- 

 ened disaster did not materialize, there being very few of the midge 

 larvae remaining in the heads, where a short time before there had 

 been myriads. To me, who had watched the proceedings daily, it 

 was clear that the crop had been saved from serious damage, if not, 

 indeed, a loss so great as to render the field of too little value to 

 harvest. One day at harvest the farmer himself was observed stand- 

 ing with a neighbor near the borders of his field, and I caught a few 

 words of his conversation as I passed by, to the effect that his success 

 in wheat growing that year had been due to good farming. I asked 



