71 



probably winters over in the fields, in other stages besides the egg, al 

 though we have never yet found them on grain during the early part 

 of the year. 



An undescribed species of Bhopalosiphum was found on spring grown 

 volunteer wheat, on July 12, of the present year. A few days later 

 adults, both winged and wingless, and young in all stages of develop- 

 ment, were found on the heads of orchard grass, Dactylis glomerate, 

 and also on the heads of spring sown rye, working- precisely after the 

 manner of the true Grain Aphis. This species I was not able to follow 

 in the fields after about the 10th of August, when it left the heads of 

 rye, and, though a large number were placed on young wheat plants, 

 in a breeding cage, all seem to have died. 



When this last species was confined on wheat, the same cage and 

 plants were utilized as had been used in the attempt to carry the true 

 grain Aphis through the months of July and August. But as none of 

 the many individuals placed on the plants survived, a large number of 

 heads of rye thickly infested by the Bhopalosiphum were placed in the 

 cage. When the first winged adult appeared in this cage, I was not a 

 little surprised to find it belonged to neither one of the species inten- 

 tionally placed in the cage, but to a species of Myzus, which could have 

 only gained admission by being introduced with one or the other or both 

 of the other species. 



By whatever way it gained admission, this Myzus has continued to 

 throw off generation after generation, and at date of writing, Novem- 

 ber 25, is still reproducing, although during the entire time — nearly 

 four months — it has had no other plants except wheat upon which to 

 subsist. It is undescribed. 



Still another species (a Megoura sp.?) was found giving birth to young, 

 on leaves of young rye, August 9, but not observed afterwards. 



The natural enemies of the Grain Aphis were, as we might expect, 

 unusually numerous the present year, and especially those belonging 

 to the Hymenoptera. Of these we had reared, during other years, a 

 species of Trioxys in quite abundance, and this season the following 

 occurred in great numbers : Bassus sycophanta Walsh, Aphidius arena- 

 phis Fitch, Isocratus vulgaris Walker, Encyrtus ivebsteri Howard, Allo- 

 tria tritici Fitch, Megaspilus niger Howard, Pachyneuron micans Howard. 



Of the Syrphids, Sphaerophoria cylindrical Xanthogramma emarginata, 

 and Allograpta obliqua were very numerous. A secondary parasite, 

 Bassus sycophanta, was in some localities so exceedingly abundant that 

 nearly all of these useful flies were destroyed. 



Two species of Chrysopa were exceedingly useful. In a field of 

 wheat, near Indiauapolis, about the middle of June, these were so 

 abundant that at every step, from one to four or five individual adults 

 would be disturbed, and take wing. The field was but very slightly 

 attacked by Siphonophora. 



