226 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
for the spraying of potatoes, because of the danger of injury to the 
plants. However, with both apples and pears large amounts of lime 
may be applied with little fear of injury. 
Mr. Leroy Childs : In my experimental work I found sulphur dust 
could be used for control. I am wondering if any work with dust has 
been carried on. 
Mr. P. J. Parrott: No. 
Mr. Leonard Haseman: This work on potato leafhopper bears 
directly on one of our projects. I would like to ask Mr. Parrott 
whether in his opinion the burning is due to the sucking of sap or to 
the possible introduction of poison? 
Mr. P. J. Parrott: My opinion is that with plant lice and insects 
of that character there is not only injury as a result of the extraction 
of the juices of the plant, but I think there is something in the salivary 
secretions of the insects which is toxic to plant tissues and thus accen¬ 
tuates the injury. 
Mr. E. D. Ball: I would like to raise one further question. We 
have a large number of sucking insects occurring on a large number of 
plants. It does not seem to make any difference what plant the 
potato leafhopper feeds on, whether a potato plant, a Dahlia, a box- 
elder, an apple tree or a raspberry bush, it always causes this burning. 
We have leafhoppers on practically every one of those plants, and 
none of them produce anything of the kind. The burning is limited 
to a specific insect. Further than that, the explanation is very largely 
yet to come. 
Vice-President A. G. Ruggles: The next paper is “The Straw¬ 
berry Root Worm Injuring Roses in Greenhouses/’ by C. A. Weigel 
and E. L. Chambers. 
THE STRAWBERRY ROOT-WORM INJURING ROSES IN 
GREENHOUSES 
By C. A. Weigel and E. L. Chambers 
The immediate circumstances leading up to this investigation were 
the simultaneous reports received by the Bureau of Entomology con¬ 
cerning two widely separated infestations of an insect injuring roses 
in greenhouses at Alexandria, Virginia, and Richmond, Indiana. The 
specimens which accompanied these reports upon examination were 
found to be a chrysomelid beetle, the strawberry root-worm, Pavia 
canellus Fab. 1 This pest though frequently reported as a serious 
enemy of strawberries, has hitherto not been reported as injurious to 
1 Fabricius, J. E., 1801, Syst. Eleut., p. 52, Vol. 2. 
