56 THE FLORIDA ENTOMOLOGIST 
ornamental plants where they lived during the early part of the 
year. In the fall they again appeared on the cabbages, turnips, 
radishes, rape, etc., as they had done the previous year. They 
continued to live on these plants in more or less abundance all 
through the winter. They also appeared in November on peach 
tree leaves, and in December on some fresh garden plants, as 
beets, carrots, kale, etc. All through the winter they could be 
found in more or less abundance on most young fresh garden 
plants, also on sunflowers and various weeds. In the greehouse, 
also, they lived on several plants but were very abundant and 
destructive on the young shoots of the orange trees. Hence it 
appears that Myzus persicae selects always the plants that are 
coming up fresh, instead of remaining on one plant all the year. 
Life History. An effort was made to breed this species in 
jars throughout the winter and thus determine if reproduction 
was entirely parthenogenetic or if sexual forms occurred; also its 
rate of reproduction and other factors of biological importance. 
The work was carried on one winter in the greenhouse and the 
following winter in the open air insectary which was then avail- 
able. Although the aphids probably reproduced faster in the 
greenhouse than under natural conditions, a line on the maximum 
number of generations could be obtained in the open air insectary, 
as well as its method of living and other data of importance. 
For the purpose of the experiment, small cabbage plants were 
used, these being placed in pots and protected with lantern globes 
which were set over the plants and the top covered with a piece 
of cheese cloth. These pots were placed on the greenhouse bench 
and the plants kept in the best possible growing condition. Start- 
ing with six adults an effort was made to carry six lines of the 
aphids through the winter. The first-born young was removed 
by means of a camel’s-hair brush and placed on a new plant. 
Then, to be more sure of preserving the line, the next two or three 
were placed on a substitute plant to be used in case the first 
one should die or be lost. Only the first young was raised to 
maturity and its offspring kept in the same way. However, after 
carrying on the work for three or four months it was found that 
the greenhouse was not a desirable place for it. In fact, it was 
impossible to carry through a line there. A fungus disease be- 
came so prevalent as to kill off the aphids before reaching ma- 
turity and thus whole lines were lost. Also the extreme heat on 
bright days caused the plants to wilt from drying out and the 
aphids, as a result, would die; therefore the work was abandoned 
in the latter part of April until the following fall. 
