INSECT ENEMIES OF EASTERN FORESTS 35 
Flea Beetles 
Flea beetles were difficult to control before DDT became available, 
because the arsenicals apparently were distasteful and repelled them. 
Excellent protection results from DDT sprays when they are thor- 
oughly apne to all parts of the foliage. Several applications at 
about’ 10 -day intervals will be required to take care of new growth. 
Bordeaux mixture is also repellent, but will give protection against 
some species of flea beetles. 
Leaf-Cutting Ants 
Atta texana Buckley, the leaf-cutting ant, can be controlled by in- 
jecting methyl bromide into the nest by means of a funnel and a lone 
tube inserted deep in a few of the main entrance holes. Such control 
work must be done before the trees are planted or after the latter 
part of November. Control work during the summer when the ants 
are more active and scattered over a wider area is ineffective. It re- 
quires about 1 pound to treat the average colony. Reasonable care 
should be exercised when methyl! bromide is used. 
The Florida harvester ant (Pogonomyrmex badius (Latr.)), which 
carries off seeds and cotyledons of young pine trees in nurseries in the 
Gulf States, makes a small mound nest in the nur sery, not extending 
very deep into the soil. It can be controlled by using carbon disulfide 
in the same manner as for the control of white grubs, or, if skilled labor 
is employed, by injecting into the nest 1 ounce of ‘powdered calcium 
cyanide. 
Calcium cyanide liberates a gas which is deadly to all forms of 
animal life, and this material must be used only by experienced 
operators. Containers of the cyanide should never be opened 
indoors, and the gas or fumes must not be inhaled. 
Walter, Seaton, and Mathewson (424) and Johnston (259) have 
published papers on the leaf-cutting ants. 
SAP-SUCKING INSECTS 
Sap-feeding insects cannot be controlled by stomach poisons, such 
as the arsenicals, because the plant parts on which the poison would 
be sprayed are not eaten. They feed by inserting their beaklike mouth 
parts into the plant tissues and drawing out the Juices. Contact 
insecticides, that kill by coming in contact with the body, must be 
used. Recent work with DDT on many insects in this group indicates 
that it offers promise as a control for this type of insect, owing to its 
long residual effect. Prior to its discovery it was impracticable to 
attempt control of many of these insects on a forest-wide basis. 
Aphids 
A number of generations of aphids are produced during a single 
season, and the population builds up rapidly under favorable condi- 
tions. Infestation should, therefore, be treated early. The usual 
recommendation for control is a spray made up as follows: 
For For 
Materials: large quantities small quantities 
Nicovinessulfate (40 percent) _—=-—~—-—__--_—. 1 pint 1 teaspoontul. 
AVA Cie eerenet Pee ie ee a ee ee Bee Ee 100 gallons 1 gallon. 
Laundry soap or fish-oil soap_-__--------- — 3-4 pounds 1 tablespoonful. 
