Feb. si, 1916 
Green Apple Aphis 
959 
been kept in a cellar all winter, and later young green apple seedlings 
grown in pots. In handling the dormant stock the tops were cut off, 
leaving a stem of 4 or 5 inches, and growth was started by keeping the 
roots in water for 8 or 10 days before planting. 
The plants were covered by lantern-globe cages—inverted lantern 
globes with cheesecloth fastened over the bottom by a rubber band. 
After the first two weeks all work was carried on in an insectary all 
four sides of which were made of fly screen. This duplicated normal 
conditions very closely, except that in most cases the direct rays of the 
sun could not reach the plants during the middle of the day. 
In the actual handling of the insects it was found that it was much 
better to transfer adults than young, as this transfer of adults could be 
accomplished much more quickly and with greater safety, there being 
less danger of breaking the beak of the mature insects. Consequently 
several generations were reared, one after another, on one plant. This 
was also of great advantage in studying the effect of a prolonged use 
of good or poor food. 
The usual custom in rearing aphides appears to be to raise the first 
bom from the first bom and the lagt from the last throughout the season. 
Since it was desired to raise young from both wingless and winged 
mothers in every case, this method proved to be impracticable. More¬ 
over, the opinion was held—an opinion which has been confirmed by 
the past season's work—that the thorough study of a species can not 
be accomplished by such methods, because too few insects are reared. 
Consequently, as many insects as possible were carried to maturity, the 
number varying between a few to 60 or more for each experiment. The 
winged forms were transferred to new plants as pupae. The wingless form 
was reared to maturity, and then all but from one to three insects were 
removed, these few being allowed to reproduce. All molts and speci¬ 
mens of insects from each generation were mounted for further study. 
At first each individual molt was mounted on a separate slide, but later, 
as their number grew into the thousands, this was impossible and a series 
of molts was placed on each slide. The total number of experiments 
conducted during the season was 1,720, with an approximate total of 
15,000 insects. These insects, together with their molts, thus gave us 
for study nearly 75,000 individual forms of known lineage. The study 
of these forms has been tedious, but it has been a valuable adjunct to the 
actual breeding, furnishing many data which would otherwise have been 
unavailable*. 
It should be understood that, while the method above outlined was 
followed as closely as possible, it could not, from local causes, be applied 
in every case. However, it has been found to be very satisfactory and is 
believed to be a more efficient method for a thorough scientific study of 
the life history of aphides than any that has been seen recorded. 
