POTATO INVESTIGATIONS LABORATORY
Mimeo Report 59-3 November 15, 1958
CONTROL OF INSECTS ATTACKING IRISH POTATOES IN THE HASTINGS AREA1
R. B. Workman
During the past several years, the wirevo Conoderus has
become very difficult or nearly impossible to ca o. i ,er elds.
This severe problem is apparently due to the e ent of resace in
wireworms to the soil insecticides used in this Thus, t trials
that formerly killed the wireworms no longer do t job.
Parathion has given good control in South Carolina ag i nst resistant
C. fall in both laboratory and field trials.
Field tests at the Hastings Potato Investigations Laboratory in 1958
were destroyed by cold weather. In laboratory tests, however, wireworms
collected in the immediate area were found to be very susceptible to para-
thion. Good control was obtained with as low as j pound actual per acre.
Aldrin at the rate of four pounds actual per acre produced no mortality.
Based on the results above and on recommendations in South Carolina,
parathion is recommended at two pounds of actual toxicant per acre in the
Hastings area where wireworm control has been difficult.
Apply the insecticide 2.3 weeks before planting. At this time, the
adult beetles have disappeared and no further wireworms are being produced.
The insecticide should be applied to the soil and disked in immediately
afterwards. Thorough mixing of the insecticide into the upper 4-6 inches
of soil is very important. In spraying the insecticide on the soil, the
nozzles should be positioned about six inches above the soil surface and
arranged so that a uniform coverage is obtained. The use of a pressure of
100-150 pounds will reduce the amount of spray lost into the air. Apply
the insecticide when there is little or no wind and disk and rebed immedi-
Use 1 quart of 25% DDT emulsion and 1.2 pints of a palathlo emulsion
(or 1-1 pint of a 50% parathion concentrate) in 100 galans of water per
acre. Spraying with this combination about every 10 days will generally
provide satisfactory control.
Apply a mixture of 5% DDT and 2% parathion dust at the rate of 20-30
pounds per acre every 10 days
1Revision of WMiew report 58-3
Regular spray applications should begin
foliage feeders appear. These materials may
solution with the fungicides used to control
when the first aphids or other
be combined in the same spray
The use of the insecticides recommended for control purposes on
involves no poison residue problems. In case some other material is
it is suggested that its status with regard to residue tolerances be
understood and honored.
to be used,
TABLE 1.--Conmon Insect Pests of Irish Potatoes in the Hasting Area
Insecticide Amount in
Insect EC = Emulsible 100 gals./A General Statement
Concentrate or total
D = Dust dust A
Parathion 2%EC 1-2 pints
Aphids Parathion 2. D -20-25 lbs.
_____ DDT 25% EC 1 art Controls small infestation
Toxaphene 70 EC 1-2 lintia Frequently attack newly
Cutworms Toxaphene 10%D 25-30 lbs. emerged potato plants.
DDT 25 C I quart
DDT Db ,6__ 2 -30 lDs.
Leaf-footed Parathion 257 EC -2 pints
plant bug, Parathion-2 D 2*3 ibs.
green stink bug Chlordne 72% EC 1 pint
Serpentine Parathion 2 EC 1-2 pints
Leaf-miner Parathion 2D 0-30 as.
Wirewors Pr on 25 EC y as discussed under
Pa is c l n fl 40il insects.
I (Is, actual/gal.)