Dec. ix, 1916 
Macrosiphum granarium 
479 
turn brown. On November 4 they had the usual leather-like appearance 
and each one was firmly glued to the leaf. On November 23 part of 
these old bodies were taken indoors and kept at the ordinary room tem¬ 
perature. The temperature went much lower at night than during the 
day, as the fire was allowed to go out. On December 2, male A. nigripes 
began to emerge and on the 4th all had emerged that were brought in¬ 
doors. The ones that were left outside were still in the larval stage. 
This is probably the stage in which they pass the winter. 
OTHER INSECT ENEMIES 
The late F. M. Webster made more observations on the parasites and 
predacious enemies of M. granarium than any other entomologist. His 
notes from 1884 to 1890 that are on file in the Bureau of Entomology 
record the following insects as attacking this aphid: 
CODEOPTERA 
HYMENOPTERA 
Podabrus tomentosus Say. 
Coccinella g-notata Herbst. 
Hippodamia parenthesis Say. 
H. convergens Guerin. 
H. iypunctata Linnaeus. 
H. glacialis Fabricius. 
Anatis i$-punctata Olivier. 
Megilla maculata De Geer. 
DIPTERA 
Allograpta obliqua Say. 
Sphaerophoria cylindrica Say. 
Xanthogramma emarginata Say. 
Aphtdius avenaphis Fitch. 
(Dioeretus) Praon americanus Ashmead. 
(D.) Praon brunneiventris Ashmead (= 
Praon americanus ). 
(D.) Praon ferruginipes Ashmead (— 
Praon americanus ). 
Isocratus vulgaris Walker. 
Encyrtus websteri Howard. 
Pachyneuron micans Howard. 
Allotria tritici Fitch. 
Riley (9) records in addition the following: 
COLEOPTERA 
HYMENOPTERA 
Coccinella sanguinea Linnaeus. 
DIPTERA 
Syrphus americanus Wiedemann. 
Aphidius granariaphis Cook. 
Tetrasiichus ingratus Howard [no men 
nudum ] 
Megaspilus niger Curtis. 
All of the parasites listed, however, are not primary. In recent years 
two species, Pachyneuron sp. and Allotria sp., have been definitely proved 
to be secondary parasites. It is very probable that others in the list 
will be proved secondary upon further study. 
FUNGUS ENEMIES 
This aphid seems to be very susceptible to fungus attack. During 
warm, moist weather rearing cages have to be carefully watched or fun¬ 
gus will soon gain control. It undoubtedly destroys many aphids in the 
fields also. 
66847°—16-2 
