EXPERIMENT STATION REPORTS. 



As soon as the presence of a serious outbreak became established, 

 the department took steps to oljtain samples of infested straw from 

 stan(Hng grain, through its own members, the coimty agricultural agents, 

 the State Crop Improvement Association, and through Professor A. C. 

 Conger of the Department of Zoology, all of whom kindly assisted. 

 These samples, numbering , several hundreds, were collected for the most 

 part, from the southern half of the State and were suitabl}'^ caged and 

 observed daily. During the summer thousands of parasites belonging 

 to five species emerged from the caged straws. The following list is ar- 

 ranged in order of their numerical importance: 



*1 . Ditropinotv>i a u reo- 

 riridis 



2. 



phagus 

 3. 

 4. 

 o. 



nosa 



Homoporus chalcido- 



Eupelnius alynii 

 Eupelminus saltator 

 Eridontomerus p r ?< i - 



Parasite of Wheat Joint-worm. (Dilrnpinolus 

 aurroviridis) enlarged (.original). 



These parasites were pretty 

 generally distributed over the 

 lower half of the State, the 

 Ditropinotus being by far the 

 most common, and on sev- 

 eral occasions this latter species 

 was seen to be ovipositing back 

 in the dried straws from which 

 t he adults had recently 

 emerged. 



The cages were placed in the cold room of our insectary so that tlu^ 

 «traw with th? llvijg joiiit worms and whatever parasites w?re present 



might experience approxi- 

 mately outside conditions. 

 They were, howevei-, brought 

 into the warm room in 

 March in order to hasten 

 the emergence of such life 

 as might be prestmt. As a 

 result, we obtained thous- 

 ands of the joint worm adults 

 and quantities of another 

 species of parasite, Eurotoma 

 bolteri, which closely resem- 

 bles the joint worm itself in 

 the adult stage. Last of all there emerged another large crop of Ditro- 

 pinotus, evidently the result of eggs laid in the cages by the adults that had 

 emerged during the previous summer. 



This year (1919) the joint-worm seems to be scattered pretty well 

 over the State, but only in comparativeh' few cases is the infestation 



Parasite of Wheat Joint-worm (Eupelminus sallalor) 

 enlarged (original). 



*Kindly determined by Mr. \V. J. Piiiliips of tLc Bureau of Entomology. 



