30 THE FLORIDA ENTOMOLOGIST 
lived on them. However after a few days the leaves wilted and 
dropped and the aphids began to die. Some winged ones were 
produced on all but one of the cuttings, but with no regularity. 
A little later the experiment was repeated, this time with 
Myzus persicae on orange cuttings. The cuttings were prepared 
as described above. Three or four dozen aphids were placed on 
each and watered with the same solutions as above and in the 
same order. The results as recorded show that wings were found 
in all but one, a cutting watered with sodium chloride solution. 
This cutting did not last very long before the leaves turned brown 
and dropped. In fact the cuttings watered with the chemical 
solutions showed the effects sooner than the checks in all cases. 
In this experiment the checks produced more winged specimens 
than any of the others except those watered with magnesium 
sulphate which produced about an equal number. Possibly this 
can be explained by the fact that the cutting did not wilt so 
quickly and hence more of the aphids had an opportunity to 
mature. At any rate, the wilting of the stems or the effect of 
the chemicals cannot be said to produce wings. 
Lachnus pini on Pine Cuttings. Four branches were cut from 
a pine tree and placed in bottles one each containing a 3% solu- 
tion of magnesium sulphate, sodium chloride and citric acid and 
distilled water. On each of these branches were placed about 
four dozen immature aphids of Lachnus pini which were allowed 
to mature. The mouths of the bottles were plugged with cotton 
and the whole bottle and stem covered over with a bell jar. 
Results show that in all cases except the check a majority of the 
aphids died while still immature and in the check also a large 
number died before becoming adult. The greatest mortality was 
noted on the stems kept in sodium chloride and citric acid. The 
leaves soon began to dry up there and the aphids died. In all 
cases however some winged ones were produced but most in the 
check. Here also we can say this is due to the fact that more of 
the aphids lived to become adult on the check. 
Injections of Chemicals into Plants. To make more sure of 
getting the chemicals into the sap of the plant and thus adding 
them to the food of the aphids, they were injected into the grow- 
ing stems with a hypodermic needle. This method was used on 
both cabbage plants and orange trees. Eight growing healthy 
cabbage plants were potted and placed under lantern globes in 
the open-air insectary. The same chemicals as used above were 
