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 Rhopalosiphum was found on spring grown 
volunteer wheat, on July 12, of the present year. A few days later 
aduits, both winged and wingless, and young in all stages of develop- 
ment, were found on the heads of orchard grass, Dactylis glomerata, 
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 Rhopalosiphum were placed in the 
eage. 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 avena- 
phis Fitch, Isocratus vulgaris Walker, Encyrtus webstert Howard, Allo- 
tria tritict Fitch, Megaspilus niger Howard, Pachyneuron micans Howard. 
Of the Syrphids, Sphaerophoria cylindrica, 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 Indianapolis, 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. 
