272 STATE BOARD OF AGRICULTtJREi. 



dates, it was impossible to do so, with the result that early sowing has 

 favored the increase of the Hessian fly which is at present well established. 

 A repetition of early seeding bids fair to result in serious losses next year. 



The work of Doctor W. L. Chandler has progressed very satisfactorily. 

 This spring an inquiry into the life history of the ox-warble (grub-in- 

 the-back) was started, and three calves were isolated in a specially con- 

 structed, screened building, in order to shut out the parent flies of the 

 ox-warble from depositing any eggs other than those under observation. 

 Many larvae were collected from the backs of cattle in our herds and the 

 adults bred. Thus far no success has attended the attempt to induce 

 these flies to oviposit on the calves in the sheds. Neither could he get 

 the flies outside to utilize his particular calves for purposes of egg-laying, 

 although several were captured and attempted to do so. It would seem 

 that the ox-warble will not oviposit in captivity. It is hoped that these 

 difficulties may be overcome, however, amd definite information ob- 

 tained from further attempts. 



An experiment dealing with the determination and prevention of gapes 

 in poultry was started this spring. Some very interesting data have been 

 obtained, but it is too early to report the results as yet. 



THE WHEAT JOINT-WORM. 



BY R. H. PETTIT AND EUGENIA MCDANIEL. 



A tiny wasp-like insect that induces swellings and woody growths 

 in the straws of wheat and barley plants, causing some of the plants to 

 bend at sharp angles and lodge, besides interfering seriously with the 

 full development of the kernels. 



Three times, at least, Michigan has suffered outbreaks of this pest — 

 once in 1884, at which time Professor A. B. Cook records it; once in 1905 and 

 1906, which outbreak was observed by one of the writers, and once during 

 the summer of 1918. This last invasion, like the others was wide-spread, 

 but in this case, the common wheat joint-worm was accompanied in some 

 counties by a less common species called the wheat sheath-worm, I. vagin- 

 icohim. While the common wheat joint-worm is always with us here 



Wheat Joint-worm,^ (/sosomo tritici). Male at left, female at right, enlarged (original). 



