E6~~ 7k 5r
m2 20 '1972
AGRICULTURAL RESEARCH CENTER
iimeo Report BBL 71-8 1Sd mr.l3,, 1971
INSECTICIDE EFFECTIVENESS Ii CONTROLLING C
ECONOMICALLY IIMORTA1iT INSECT/MITE PESTS OgEA ECkE"
Sam S. Fluker d
Asst. Entomologist f LrS. O
Commercial peach growers are constantly operating at a reduced margin of
profit. Less expensive methods of controlling insect pests effectively is one
way of increasing this low margin of profit. Therefore, an experiment was initi-
ated this year to test the effectiveness of concentrate formulations of various
insecticides against the catfacing insect complex and a parathion resistant popu-
lation of the two spotted spider mite, Tetrrnychus urtisae (Koch).
At the Agricultural Research Center, Monticello, 109 seven-year old peach
trees (IHaygold variety) were selected for the experiment. The trees were marked
so that from 10 to 13 trees were treated with one of the insecticide formulations
in Table 1.
Table 1 Insecticides applied to peach trees,
Chemical and Formulation
Parathion 4 EC
DuPont Lannate 25% H.P.
Velsicol Phosvel 3 EC
Hiagara Thiodan 2 M
Velsicol Phosvel 3 ULV
Geigy Supracide 2 E
Niagara Furadan 4 F
T.H. DE-FETD 267 E
T.H. DE-FEND SULV
A.R.C., Monticello, 1971
Each tree was treated five times beginning March 16, with the last spray
applied Hay 25, approximately 10-15 days before harvest. In addition to the in-
secticides applied, each tree received at 10-day intervals 80% wettable sulfur at
the rate of 2.99 ozs. of 80% wettable sulfur/tree. All insecticides were applied
using a Soloe Nodel 423 mistblower. Each insecticide, except the ULV formulations,
was applied at 12x concentrations or approximately 32 ozs. of formulated material/
tree. To apply the ULV formulations an ultra low volume attachment available from
Solo Co. was used. With the use of this attachment rates as low as 2.4 ml./tree
All treatments were sampled with a D-Vac' before and after each insecticide
application. This was to determine the activity of the catfacing insects, specif-
ically the tarnished plant bug (Lygus lineolaris (P. de B.) and the southern
green stink bug (Nezara viridula (L.). Also, other insects of economic signifi-
cance could be collected in the D-Vac collections.
The fruit samples from each treatment consisted of the entire fruit crop.
Each peach that was harvested was examined for insect damage.
Nine trees were selected as check trees and did not receive insecticides
throughout the 1971 season. However, these trees did receive regular applications
of 80% wettable sulfur at the recommended rate.
The 1st sample with the D-Vac revealed the presence of the tarnished plant
bug. This sample was taken at petal-fall. The following day, all trees were
sprayed with the proper insecticides. Thereafter, no tarnished plant bugs were
found in any subsequent D-Vac samples. The southern green stink bug began appear-
ing in the D-Vac samples approximately Hay 1. As the peaches neared maturity
(mid-June), two insects, the big-footed plant bug (Acanthocephala femorata (F.)
and the leaf-footed bug (Leptoglossus sp.) began to appear in the collections. Of
the two insects, the leaf-footed bug was by far the more numerous. Observations
in the field revealed numerous leaf-footed bugs feeding on the fruit. As many as
6 leaf-footed bugs/fruit were observed as the fruit reached maturity. Although
the southern green stink bug and the leaf-footed bugs are not responsible for the
catfacing damage to peaches, the feeding of these insects on the maturing peach
does provide an entry for the brown rot fungus. Brown rot was severe this year
and many peaches were ruined by it. Because the above mentioned insects are
strong fliers and fly readily, no significance was attached to the areas in which
these insects were collected. In fact, the samples showed a random distribution
Of 32,722 peaches harvested from the 109 trees, 866 had insect damage.
The data of Table 2 indicate that all insecticides gave adequate control of the
catfacing insects. Treating the data from Table 2 statistically using a linear
regression method described by Snedecor (1956) resulted in a non-significant
difference between treatments at the 99% confidence interval.
Table 2 Number
of peaches harvested in insecticide test. A.R.C., Monticello,
% of catfaced
fruit in harvest
The last insecticides were applied to the test trees on May 25. Between
May 25 and July 14, no insecticides were applied to any test trees. On July 14,
all test trees were checked for the presence of mites, specifically the two-
spotted spider mite. Nine of 10 treatments were found to be heavily infested
with the two-spotted spider mite. Ten leaves that showed signs of heavy infesta-
tion were selected from each tree in each plot. The number of live mites from
the underside of each leaf was counted. The data from Table 3 indicates that
Thompson-Hayward DE-FEND SULV (Dimethoate) gave excelle-t control of the two-
spotted spider mite. In this experiment all other insecticides used gave less
than satisfactory control of the two-spotted spider mite.
Table 3 Two-spotted spider
mite infestation on peach trees.
Avg. No. Mites/leaf
(10 leaves counted)
Parathion 4 EC
Lannate 25% 7U.P.
Phosvel 3 EC
DE-FEND 267 E
Phosvel 3 ULV
trees sprayed 7/16
trees sprayed 7/30
The insecticide, DE-FEND SULV, was superior for controlling the insect and
mite pests of economic importance on fruit and foliage of peaches in this test.
Also, because DE-FEND SULV was applied at the rate of 10 Ml. of formulated
material/tree, the cost of applying the material would be low compared to the
other insecticides tested. An exception to the cost factor in application would
be Phosvel 3 ULV, since it was applied at the rate of approximately 2.4 ml. of
Snedecor, G. U. 1956. Statistical Methods, The Iowa State University Press,