414 
Journal of Agricultural Research 
Vol. XXI, No. 6 
of the jointworm, and the first generation of this parasite begins to 
emerge about the first week in June and the second generation about 
the first week in July in Virginia, according to the authors' records. 
Previous to the season of 1918 it was supposed that there were only 
two generations each year; but during 1918 and 1919 two complete and 
a partial third generation were reared in glass cell slides, 1 and apparently 
a partial third one was reared from the field in 1919. There appeared 
to be only two main generations annually in the field, and further ob¬ 
servations, therefore, are necessary before it can be determined definitely 
whether there is normally a partial third generation under field conditions. 
Fig. 6.— Ditropinotus 
aureovirtdis: Pupa of 
female. X 25. 
Fig. 7. —Ditropinotus aureovt- 
ridis: Pupa of male. X 28. 
The largest number of eggs secured from a single female was 18 during 
a period of 12 days. One female lived 48 days. When the female is 
ready to oviposit she walks up and down the wheat stem, tapping it 
with her antennae until a jointworm gall is located. After locating a 
suitable cell the female brings the abdomen almost at right angles to the 
thorax, at the same time elevating the body as much as possible. She 
then touches the tip of the ovipositor to the surface of the wheat stem. 
In this position she uses her ovipositor very much as a gimlet until it is 
forced into the Harmolita cell, at which time the body assumes its more 
nearly normal position. The egg, after oviposition, has the same shape 
as before oviposition. Five to 10 minutes are required for the female 
1 This observation was repeated in 1920 with the same results. 
