STUDIES ON THE CONTROL OF THE CLCVEF ROOT BORER Hylastinus obacurua (Marsham) IN OHIO WITH NOTES ON COINCIDENTAL CONTROL OF THE JEADCW SPTTTLEBUG
Dissertation
Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University
37 BERNARD AUMAN APP, A.B., H.S. The Ohio State University 1953
Approved By:
Adviser TABLE OF CONTENTS
Acknowledgement s...... • 11
Introduction...... 1
Plante Attacked...... 2
Damage...... 3 Classification and Synonomy...... 4
Life History, Appearance, and Habits...... 5
Control...... 8
Summary of Previous Work 1947-49...... 9 Etcperinents in 1949-50...... 9
Experiments in 1950—51...... 22
Experiments in 1951—52 ...... • 29 Insecticide Residues. •...... 40
Effect of the Root Borer Treatment s on the Meadow Spittlebug44
Summary...... «••«••••••••»•• 56 Literature Cited...... 61
Autobiography ...... • • « 64
1 & 3 S 1 8 - ii
ACKNOWLEDGEMENTS
The research presented in this dissertation was conducted at the
Legume Seed Research Laboratory maintained cooperatively by the United
States Department of Agriculture, The Ohio State University, and the
Ohio Agricultural Experiment Station* I am much indebted to Dr* F, W*
Poos in charge of legume insect investigations for the Bureau of Entomology and Plant Quarantine for his suggestions and encouragement* Special acknowledgement is due Dr* Ralph H* Davidson for his advice and counsel during the conduct of this research* 1 also wish to thank Dr. A* W* Woodrow and Mr* John G* Dean, Jr* , of the Legume Seed Research
Laboratory for their assistance, Dr* Kennit W* Kreitlow, pathologist of the Bureau of Plant Industry, Soils, and Agricultural Engineering, and
A* G. Schmitthenner, pathologist, of the Ohio Agricultural Experiment
Station for their help with the fungicide studies* The assistance of the personnel at the Ohio Hybrid Seed Corn Producers Research Farm at
Croton, Ohio, and of Mr* Cecil Robinson at Delaware, Ohio, who provided land, crops, machinery, and labor for these experiments is gratefully acknowledged. Sincere appreciation is due Messrs. Elbert L* Sleeper,
Alan L. Steffen, William A* Piersol, Jon A* Peterson, Robert L* Pienkowsky, David M* Daugherty, and George W* Layne, Jr. for their valuable assistance with the field work* INTRODUCTION
The clover root borer H.ylagtinus ob3cunis (Marsham) is an insect of European origin introduced into the United States sometime prior to
1878* Since this time it has spread to all parts of northern United
States and Canada wherever red clover is an important crop* The control of this pest with insecticides was unsuccessful before the tremendous progress in the development and use of organic insecticides following the discovery of the insecticidal properties of DDT* Marshall et al (1949) reported that studies made in 1946*-48 showed that benzene hexa— chloride at 1*5 pounds of the ganroa isomer per acre furnished excellent control of the borer* Everly and App (1949)> App (1950), and App and Everly (1950) reported that dusts of benzene hexachloride at 1*25 pounds of the gamma isomer per acre, sldrin at 2.0 pounds, chlordane at 5*0 pounds, and parathion at 5«0 pounds all gave good control. Studies on the control of this insect were continued during 1950, 1951 end 1952 in order to obtain data on (l) the minimum effective dosages of the more promising materials, (2) the effectiveness of other new insecticides,
(3) practical methods of applying the materials, (4) the effect of the treatment on forage or seed yields, (5) the comparative effectiveness of sprays and dusts, (6) the effect of adding a fupgicide to the insecti cide, and (7) the insecticidal residues present on clover forage.
Certain data on the life history, host plants, and damage largely taken from other sources are included in this report. _ 2 -
RECORD OF SPREAD
The first report of the clover root borer in the United States was
by Riley (1879) *bo mentions it as attacking red clover in western
New York in 1878. Lintner (1879) reported this insect as one of two
important pests of clover in New York* Webster (1905) states that the
insect was probably present much earlier but that its ravages were attributed to adverse weather conditions. Davis (1894) reports the insect as damaging red clover in Michigan in 1394* The clover root
borer was first observed in Ohio in 1890. Webster (1899* 1910) records observations in Ohio and states that he believed it was washed into the upper tributaries o f the Ohio river during periods of high water and
became established after the waters receded. Folsom (1909) records this
insect from Illinois. Gibson (1913) mentions finding the clover root
borer in Ontario. Rockwood (1926) states that this insect was recorded
on the west coast as early as 1896.
PLANTS ATTACKED
The clover root borer attacks and damages principally red and
mammoth clover. It has at times been recorded in considerable nunbers
from alsike clover. Davis (1894) states that any species of clover is
subject to attack. Folsom (1909) records the insect from alfalfa and
garden peas in addition to the clovers* Swain (1913) says that the "clover bark beetle" is injurious to red, mammoth, alsike and crimson
clovers in parts of Quebec and Ontario. Moznette (1917) lists alfalfa* alsike clover, vetch, field beans, and peas as additional hosts# St ear
(1 9 1 8 ) reports that the clover root borer is a pest of various clovers - 3 - and garden peas* Rockwood (1926) states that clover root borers have
been observed attacking alfalfa and sweet clover in the Yakima Valley,
Washington* Mills (1941) says that although red and mammoth clovers are
preferred it will attack several legumes including alfalfa and sweet
clover* Schwardt and Lincoln (1941) state that in addition to red clover slight damage was noted to alsike clover but none to ladino
clover, DAMAGE
In most areas red clover is planted in the spring with a companion
crop of wheat or oats* During the first year clover hay or seed is seldom harvested following the gathering of the grain crop. The follow- ing year is often referred to as the crop year* In June a crop of hay is cut and in August another crop of hay or seed is harvested* The clover roots become infested in the spring of the crop year* The larvae of the insect tunnel within and throughout the clover root, often destroying it, resulting in the death of the plant* The principle damage occurs at the time of cutting the hay crop. Many roots are so badly riddled that they are pulled out by the mower* Other plants are so weakened that they often die or make very poor regrowth* This results in a very thin and weakened stand, and little or no seed* Over the years entomologists have periodically recorded severe damage by this insect.
Often entire stands have been destroyed* Stear (1913) states that the feeding of this insect causes the clover to die out in patches and that damage is more severe during dry seasons* During wet weather the plants may survive but produce little seed* Stookey (1920) lists this insect a.3 the chief pest of red clover in Washington, Rockwood (1926) states
that the clover root borer is the factor limiting the life of red clover
to one crop year# Hudson (1936) says that the clover root borer is not
normally regarded a serious pest in Ontario since it confines its attack to plants in the second year of growth after which they are plowed under#
Sorenson (1936) reports that this insect causes much damage in one part
of Utah every year# Mills (1941) says that this borer injures the older stands of red clover# Shull (1944) states that this insect is of little importance in Idaho where the crop is maintained for one seed year# Mills (1941) and Portman and Barr (1952) mention that the feeding of this
insect allows the entrance of disease organisms# During 1947 severe
damage occurred in many clover fields in Ohio# This severe damage was one of the reasons for undertaking the present study# CLASSIFICATION AND SYNONOMY
Chamberlin (1939) in his classification of the bark beetles of
North America lists Hvlastinus obscurus as a member of the superfamily
Scolytoidea, family Scolytidae, and subfamily Hylesininae* It was first
described as Ip s obscurus by Mar sham (1802)# It was subsequently
described by Mueller (1807) as Bostrichus trifolii# Schmitt (1644) referred to the species as Hylesinus trifoH-f (Mueller)# It was called
Hylastes trifolii by Chapuis (1869) with a notation that trifolii of
Mueller is a synonym for obscurus (Marsham)# Bedel (1688) set up the genus Hvlastinus with obscurus (Marsham) as the type species# He notes that Hvlastinus is a synonym in part for Hylastes# He also notes that obscurus of Mar sham is identical with trifolii of Mueller# Hagedom (1910) lists Hylastinus as a subgenus of Hylastes and does not recognize Mar sham* r, obscurus, but retains the name t ri folii (Mueller), Guercio
(1915) refers to the genus as Hylastinus or Hylastes, The species has
been referred to as Hylastinus obscurus (Marsham) by Swain (1918), and by Chamberlin (1939)« The accepted common name for Hylastinus obscurus
(Marsham) approved by the American Association of Economic Entomologists is the clover root borer*
LIFE HISTORY, APPEARANCE, AND HABITS
Acoording to Rockwood (1926) the winter is passed as adult beetles
within the roots of old clover, A few specimens have been observed to
pass the winter as larvae. The reddish to dark brown adults are oblong
oval beetles averaging about 2,2tihu long and l,2ran, wide. The frons,
prothorax, legs, elytra, antennae, and venter are clothed with short
golden-brown hairs. The head and pro thorax are finely punctured and the
elytra are deeply 3triated, The sides of the me so thorax and metathorax are clothed with greyish scales. The a<&ilt3 resume feeding in the spring and in early May work their way to the surface of the soil and fly to new clover. Mating is believed to occur just previous to this flight.
The eggs are deposited in May or June in niches in the side of the egg burrow. After oviposition is completed the niches are plugged with frass. The eggs are pearly white and measure about 0,67 mm, long by
0,43 nr™, wide. They hatch into short, wrinkled, legle3s, creany—white larvae with a straw-colored head capsule. These larvae tunnel through out the root and it is in this stage that the damage to the clover plant occurs. The larvae be00me full grown in mid summer and pupation begins in late July and continues until early September# Pupation takes place in the burrow and lasts from 10 to 13 days. There is but one generation of this insect per year and the newly—emerged adults remain in the roots until the following spring.
The only data on the life history of the clover root borer in Ohio obtained during the present study were concerned with the time of the adult flight. These data were useful in timing the application of insecticides in the spring. During 1950, 1951* =nd 1952, 20 traps were operated to obtain the flight information. Each trap consisted of a
12 x 12 inch piece of waterproof masonite mounted on top of a 14—inch stake# The stake was set in the ground about 4 inches so the trap was about 10 inches above the surface. The surface of the trap was painted white and covered with tanglefoot# The traps were examined tri-weekly and the adult clover root borers removed and recorded# The traps were maintained in operation each year from late April until the hay crop was cut usually early in June. The data obtained during the three years are given in table 1, Adults were taken in the traps only during the month of Hay. Over the three-year period 68 percent of the adults were trapped during May 1—
10. The earliest date was May 2 in 1952 and the latest May 23 in 1950# The spring root borer treatments were applied the first week in May which corresponds to the period of heavy adult flight. Table 1,— Number of adults of the clover root borer caught in tanglefoot traps during 5—day intervals, Columbus, Ohio, 1950—52*
Year Adults caught during May Total 1-5 6-10 11-15 16-20 21-25 Number Number Number Number Number Number
1950 3 11 3 14 6 37 1951 3 2 5 1952 27 13 1 a
6 6 Total 30 2 7 14 83 CONTROL
The control of the clorer root borer with Insecticides has been
very difficult due to the fact that the larvae are within the clever
roots during the entire tine from egg to adult• Webster (1399) recom
mended the plowing of the field after cutting the hay crop and before pupation begins* This exposed the roots to drying conditions and killed many larvae. Davis (1394) suggested that no clover be grown in Michigan
for a period of years, and thus reduce the population of the root borer* Lincoln (1942) reported that p&radichlorobenzene at 1*000 pounds per acre reduced the mmfeer of infested roots and the number of borer3 per root*
Naphthalene at 2,000 pounds per acre acted as a repellent, Dichlorethyl ether also gave promising results, but all of the treatments were too expensive. In the last few years the use of the newer organic insect!-* cldes has shown good to excellent practical control, Marshall et al
(1949) reported that studies made in 1946**43 shewed that benzene hexa^- chloride hereafter referred to as BHC in this paper at 1*5 pounds of the gaaea isomer per acre gave excellent control of the root borer. From
1947—52 studies were made in Ohio with surface applications of dilute dusts or with sprays of the newer organic insecticides to determine their effectiveness against this insect. The theory was to apply the materials to yourg second—year clorer in advance of the adult migration, and poison the adults as they burrowed into the young crowns. The results of
Investigations made from September 1947 through May 1949 have been published (Everly and App 1949, App 1950, end App and Everly 1950) but for conqpleteness a brief summary will be given here* SUMMARY OF RESULTS OF 1947-49 TESTS Results obtained from the 1947*^48 tests indicated that gamma EHC
at 1*2 5 pounds per acre or chlordane at 5 pounds per acre, applied
either in the fall or spring, gave excellent oontrol of the clover root borer. DDT at 5 pounds per acre was not effective* Data from plots
treated in both the fall and spring showed that there was no advantage over a single fall or spring treatment. Samples of seed taken to show any effect of the treatments on seed production gave no significant results*
Studies conducted in 1948-49 showed that gamma BHC at 1,25 pounds and chlordane at 5 pounds per acre applied in the fall produced effective control, Chlordane at 5 pounds, aldrin at 2 pounds, gamma BHC at 1,25 pounds, and parathion at 5 pounds all gave good control. Met hooey chlor, toxaphene, and DDT were ineffective. As noted in the 1947—48 trials, applications to the same plots in the fall and spring did not show an increase in the efficiency of the materials* Samples of seed did not show any significant yield differences among the treatments. There was some evidence that some of the treatments produced a better stand, an increase in the percentage of florets containing seed, and an increase
In the number of seeds per head* TESTS CONDUCTED DURING 1949-50
The studies on the control of the clover root borer in 1949— 50 were directed toward determining the minimum effective dosages of BHC, aldrin, and chlordane applied as dilute dusts; the comparative effectiveness of sprays and dust3; and the use of farm machinery in the application of the materials* - 10 -
Tests applied September 29. 1949.— Technical BHC and BHC formulated
from 96 percent gamma isomer material at 1 pound of the ganma isomer per
acre, aldrin at 1.5 pounds per acre, and chlordane at 3*0 pounds per acre
were tested in 20 x 20 foot plots arranged in a Latin square. All of
the materials were applied as dilute dusts on September 29, 1949, using
a hand-operated Candy fertilizer distributor. These materials were
applied later and in lighter dosages than in previous yearo. Fifteen
roots from each plot or 75 roots per treatment were dug on August 3# 1950
and dissected to determine the root borer population. Table 2 presents
the data.
Of the materials tested, aldrin reduced the population 60*8 percent,
and BHC 37.2. Technical benzene hexachloride formulated from 96 percent
gamma isomer material, and chlordane were ineffective in these tests.
These fall applications were much less effective than in previous years
indicating that the lighter dosages are not satisfactory. The materials were applied about 2 weeks later which also may have influenced the re stilt s.
Plots treated May 2. 1 9 5 0 . — Cn May 2, 1950 plots 20 x 20 feet in size in a randomized block replicated 5 times were used to compare different strengths of various insecticides. Technical BHC was tested at 1.00 and at 0.75 pounds of the gamma isomer per acre, lindane at the same strengths, chlordane at 5*0 and 3*0 pounds, and parathion at 5*0 pounds. The dusts were applied with the Gandy distributor as in the fall. Root samples of 15 roots per plot, or 75 roots per treatment, were dug on August 7—6 and dissected. The data are given in table 3. 11
Table 2*— The effect of different insecticides, applied to red clover as dilute dusts on September 29, 1949, on the population of the clover root borer in August, 1950* Groton, Ohio*
Active Reduc tion ingredient Roots Total Average in total Treatment per acre infested borers per root population Pound s Percent Nuirk er Number Percent
None - 37.3 51 0 . 7 -
B H C 1 . 0 2 / 17.3 3 2 0 . 4 37.2 E H C 1 / 1 . 0 2 / 34.7 66 1.1 + 6 8 . 6
Aldrin 1*5 1 3 . 3 20 0 . 3 60 . 8 Chlordane 3*0 ■ 37.3 66 0 . 7 + 25.0
1 9 : 1 8 * 0 L.S.D. 2 / 9 9 : 1 H . 3
1 / Formulated from 93 percent gamma isomer material* 2/ Gamma isomer*
2/ Not significant* Note: A sample of 75 roots dug in a part of this field unaffected by drift averaged 4 4 * 0 percent infested and 0 * 9 1 borers per root* 12
Table 3.— The effect of different Insecticides and different rates of application on May 2, 1950* on the population of the clover root borer in August* 1950* Croton* Ohio*
Active Reduction Ingredient Roots T o t a l Average in total Treatment per acre infested borers per root population Pounds Percent Hunker Nunfeer Percent
None - 1 8 . 7 31 0 . 4 1 BHC 1 . 0 0 1 / 6 .7 27 0 . 3 6 12.9
BHC 0 . 7 5 3 / 9 . 3 24 0 . 3 2 2 2 . 6 Lindane 1 . 0 0 1 3 . 3 2 2 0 . 2 9 2 9 . 0 Lindane 0 . 7 5 1 6 . 0 30 0.40 3.2
Chlordane 5.00 1.3 4 0.05 8 7 . 1 Chlordane 3 * 0 0 8 . 0 9 0.32 7 1 . 0 Para th ion 5.00 1 2 . 0 16 0.21 4 8 . 4
Aldrin 1 . 2 5 13.3 29 0 . 3 9 6.4
Aldrin 0 . 5 0 21.3 4 9 0 . 6 5 ♦ 58.1
19*1 2/ L.S.D. 99*1
1/ Gamma isomer*
2/ Differences not significant*
Notes A sample of 75 roots dug in a part of this field unaffected by drift averaged 4 4 * 0 percent infested and 0 . 9 1 borers per root* The most effective material was chlordane at 5*0 pounds per acre
which showed a population reduction of 87*1 percent. When applied at 3 pounds per acre this material showed a reduction of 71*0 percent,
Parathion at 5,0 pounds per acre reduced the root borer population 48*4 percent. The other materials were less effective* The data indicate
that the dosages used in 1 9 5 0 , except chlordane at 5*0 pounds per acre,
were too low to furnish effective root borer control, Si tests made in
1949, BHC at 1,25 pounds of the gamma isomer, and aldrin at 2*0 pounds
per acre gave excellent control*
Comparative effectiveness of sprays and concent rated dust 3 in root
borer control*— Oh Hay 1 1 , 1 9 5 0 , an experiment was set up to determine
the effect of sprays and more concentrated dusts on the clover root
borer. Technical BHC, aldrin, and chlordane were applied as wettable
powder sprays, technical BHC and aldrin as 5 percent dusts at 20 pounds
per acre, and 40 percent chlordane dust at 1 2 . 5 pounds per acre* Both
sprays and dusts were applied with hand ecyilpaent* The plots used in
this experiment ’"rare 18 x 18 feet in size arranged in a Latin square.
Table 4 gives the population data determined by digging 15 roots per plot
or 105 per treatment on August 8 —1 1 * It appears from these test3 that sprays and more concentrated dusts
can be used in root borer control* Technical BHC as a dust was somewhat more effective than as a spray while aldrin and chlordane as sprays were
slightly better than dusts* However, an analysis of the data showed that there were no significant differences in the effectiveness of sprays and dusts in this test* Heavier dosages would have probably given more - 14
Table 4*— The effect of BHC, aldrin and chlordane applied as sprays and as dusts on May 11, 1950, on the population of the clover root borer in August, 1950* Croton, Ohio,
Active Reduction ingredient Roots Total Average in total Treatment per acre infested borers per root population Pounds Percent Nunfcer Nunfcer Percent
None - 32 . 0 83 1 . 1 7 -
BHC spray 1*0 1/ 17.3 22 .29 75 . 0 BHC dust 1*0 1/ 8.0 10 .13 88.6
Aldrin spray 1*0 14*7 32 .43 63.6 Aldrin dust 1.0 10.7 38 .51 56.8 Chlordane sp ray 5*0 6.0 15 .20 83.0
Chlordane dust 5*0 1 6 * 0 2 4 .32 7 2 . 7
16 * 1 45 * 6 9 9 : 1 22.5
1 / Gamma Isomer* - 15 - effective control* It was difficult, using hand ecjiipment, to get
exactly comparable amounts of 3pray and dust on the plots so the small differences may be due to dosage variations*
Sffect of varying dosages of technical BHC emulsion spray,- At
Croton, Ohio a 4-acre field of red clover was treated May 3 using a 12 percent BHC emulsion applied with a weed sprayer. One acre each
received 1 quart, one—half gallon, and 1 gallon of material, and one acre left untreated* The spraying was done by personnel of the Ohio
Hybrid Seed Corn Producers research farm* One third of this field was planted to each of three varieties of red clover: Van Fossen, Ken land, and Cunfcerland, On August 14, a sample of 25 roots wa3 dug from each variety for each treatment dosage* The data are recorded in table 5*
The Kenland and Van Fossen strains had somewhat less root borers than the Cunfcerland strain, but the data were so variable the differences were not significant* In general, the one—fourth pound per acre dosage was unsatisfactory for root borer control, but did show some effect in the sample of roots dug from the Cumberland strain* The one—half pound dosages of the gamma isomer per acre showed some reduction in population for the Van Fossen and Kenland strains* At one pound of the gamma isomer per acre population reductions of 33*3, 66*7, and 90*4 percent were recorded for the Kenland, Van Fossm, and Cunfcerland strains, respective ly* While the differences between strains and dosages proved not to be significant the one pound dosages were acre satisfactory and slightly heavier dosages may have proven more effective. An average of all strains ah owed population reductions of 53*2, 61*7, and 33*7 percent for Table 5*- The effect of different concentrations of technical BHC emulsion applied with a weed sprayer on Nay 3, 1950 on the population of the clover root borer in August, 1950* Croton, Ohio*
Percent reduction Percent infested roots Total number of borers Averagei number per root in total population Dosage - Pounds Dosage - Pounds Dosage - Pounds Dosage - Pounds Strain None 1/4 1/2 1 None 1/4 V* .1 None 1/4 1/2 1 1/4 1/2 1 Van Fossen 36*0 44*0 16.0 16.0 18 18 7 6 .72 .72 •28 •24 0.0 61.1 66.7
Kenland 26*0 44*0 2S.0 8.0 9 22 17 6 .36 .88 .68 .24 +144.4 ■188.8 33.5
Cumberland 52*0 28*0 32*0 20*0 114 19 30 11 4.56 .76 1.20 •44 83.3 73.7 90.4
Summary for 38.7 38.7 25.3 14.7 141 59 54 23 1.96 .79 .72 .31 58.2 61.7 83.7 75 roots - 17 - the one—fourth, one—half, and one pound rates of application, respective
ly* The studies indicate that it is possible to oontnol the clover root borer with technical BHC emulsions applied with a weed sprayer*
Control of the clover root borer with dilute dusts applied with farm
machinery*— Two methods of using farm equipment to apply dilute dusts
for root borer control were tried in 1950* On May 3 at Croton, Ohio technical BHC, aldrin, and chlordane dusts were applied with a grain
drill* The tubes were removed from the Aoes and allowed to hang loose
behind the drill* The disk was set j u s t deep enough to operate the
machine* The application of the dusts by this method was satisfactory* One hundred roots from each treatment were dug and dissected on August
1 1 - 1 4 * The data are given in table 6* As was observed in other experi ments the dosages were probably too low for excellent root borer control*
Population reductions of 63*5» 68*4* and 76.9 percent were recorded for chlordane, aldrin, and technical SIC*
At Delaware, Ohio a fertilizer distributor was used to apply dusts of BHC and aldrin* This machine covered a 3trip 10 feet wide and was
similar to the hand operated spreader used in our plot tests* The
application of dusts by use of this machine was also satisfactory. It
was noted that there was a difference in the flow of the different
materials from the machine and that different calibrations had to be made. By measuring the treated area and weighing the dusts, the dosages
could be determined* One hundred roots were dug from the treated and untreated areas on August 15 and the results are presented in table 7*
Aldrin at 1 * 8 2 pounds per acre and BHC at 1 * 4 7 pounds per acre reduced Table 6*— The effect of applying different insecticides with a grain drill on May 3, 1950, on the clover root borer population in August, 1 9 5 0 , Croton, Ohio.
Active Reduction Area ingredient Roots Total Average in total Treatment treated per acre infested borers per root populatlor Acres Pounda Percent Number Nunber Percent
None 0 * 7 0 - 88 * 0 3 0 4 3 . 0 - BHC 1 # 1 9 0 * 8 4 y 1 8 * 0 70 0 . 7 77.0 Aldrin 1»34 0 . 7 5 26.0 9 6 1 . 0 68 . 4
Chlordane 0 * 6 2 3.23 32.0 1 1 1 1 . 1 63.5
1 / G a n n a isomer# - 19
Table 7.— The effect of applying dilute dust3 of BHC and aldrin with a fertiliser distributor and of spraying BHC wettable powder with a weed aprayer on Hay 4, 1990 on the clorer root borer population in August, 1 9 9 0 * Delaware, Ohio*
Active Reduction Area ingredient Roots Total Average in total Treatment treated per acre infested borers per root population Acres Pound s Percent Nuntoer lhiwfrfn» Percent
None 0 . 5 0 •» 52.0 1 6 4 1 . 6 4 - BHC 0 . 3 4 1 / 1 * 4 7 1 8 . 0 3 0 •30 6 1 . 7
Aldrin 0 . 5 5 1.82 4 . 0 4 •04 97*6
BHC (spray) 2/ — 1 . 0 0 3 * 0 7 . 0 7 9 5 . 7
1 / Gamma isomer. 2/ Applied as wettable powder spray by commercial grower to an adjacent
area of the same field using a weed sprayer at 2 5 - 3 0 pounds pressure* - 2 0 -
the population 97*6 and €1*7 percent* In this same field the owner
sprayed an area with technical BHC wettable powder at 10 pounds of a 10 percent powder per acre using a weed sprayer* A sample of 100 roots
from this area showed a population reduction of 95*7 percent, indicating
that spraying of wettable powder of technical BHC is a practical method for root borer control*
The effect of the clover root borer treatments on the seed yields of red clover*— At Croton, Ohio the poor stand and poor pollination made
taking an adequate yield sample impossible* However, 10 stems were taken at random in each plot to study eny effects of the treatments on
seed production* Two heads from each plot or 10 heads per treatment were
dissected and threshed by hand to determine the mufcer of florets and
seeds per head* In the root borer treatments applied September 29* 1949 (see table 8) the average nurter of heads per stem ranged from 5*0 for untreated plots to 5*6 for those treated with technical BHC at 1 pound of the gamma isomer per acre* Plots treated with technical BHC averaged 107 florets per head compared with 101 for untreated plots* Plots treated with BHC averaged 21*6 seeds per head, those treated with aldrin at 1*5 pounds per acre averaged 21*1 and untreated plots 15*3* None of these data proved to be significant*
The spring root borer treatments applied Hay 2, 1950 were sampled in a similar manner* The data obtained were also too variable to be significant* Technical BHC at 1 pound of the gaama isomer per acre and chlordans at 5 pounds per acre averaged 25*4 and 24*5 good seeds per bead 21
Table 8*— The effect of various Insecticides, applied September 29, 1949 as dilute dusts for control of the clover root borer, on the seed production of red clover. Croton, Ohio.
Hate Heads Florets Seeds per head Treatment per acre per a tan. per head Good Poor Total Pounds Number Ntuber Nunfcer Number Number
None - 5.0 lOl 1 5 . 8 8 . 1 2 3 . 9 Aldrin 1.5 5.3 103 2 1 . 1 3 . 8 2 4 . 9 BHC i.o y 5.4 1 0 7 l l . b 9 . 2 2 0 . 8 Chlordane 3.0 5.3 100 1 1 . 3 5.6 1 7 * 4 BHC 1 . 0 1 / 5 . 6 1 0 7 2 1 . 6 2 . 9 2 4 . 5
1 / Gamma isomer. compared with 19*3 for untreated plots* These data are listed in
table 9* TESTS CONDUCTED DUE DC 1 9 5 0 - 5 1
Additional tests with insecticides to c o n tr o l Infestations of the
clorer root borer were conducted during the 1950—51 season* The
effectiveness of both fall and spring applications was farther investi gated using Insecticides that had shown promise in previous tests* Some
new materials were included in the spring tests* Further data were
obtained on the comparative effectiveness of sprays and dust3 for root
borer control* Plots treated September 12, 195.0*— At Croton, Ohio, plots of red
clover were treated on Septonber 12, 1950 with aldrin at 1*75 pounds
per acre, chlordane at 4*0 pounds, technical BHC at 1*25 pounds of the
gamma isomer, and lindane at 1*25 pounds* The effectively S3 of fall
applications of aldrin and lindane had not been tested previously. The
treatments were arranged in a 5 x 5 Latin square with plots 27 x 27 feet
in size. All of the materials were applied as 1 percent dusts using a
hand-operated fertilizer spreader*
To determine the effaced vena 33 of the treatments, samples of roots
were dug end dissected on August 20—21, 1951* In each plot 3 1*00 1 3 were
dug from each of 5 locations or a total of 15 roots per plot and 75 roots per treatment. The results of these dissections are shewn in table 10* 23
Table 9.*~ The effect of various ±n3ect±ciiles, applied May 2, 1950 as dilute dusts for the control of the clover root borer, on the seed production of red clover* Croton, Ohio*
Rate Heads Florets Seeds per head Treatment per acre per stem per head Good Poor Total Pounds Hiuber Nusber Nunber Nuaber Number
None - 5*4 112 19*0 5.8 25.6 BHC 1 * 0 1 / 5*6 1 0 7 2 5 . 4 6*4 33*8
BHC 0*75 1/ 6.3 92 12.0 6.0 1 8 . 0 Lindane 1.0 5.0 100 1 4 . 6 6.3 2 0 . 9
Lindane 0 . 7 5 6*0 93 11 * 4 9 . 9 21.3 Chlordane 3.0 6.3 109 1 7 . 7 4.3 2 2 . 0
Chlordane 5*0 6*3 105 24 * 5 5.0 29 . 5 Parathion 5*0 6*0 112 10.3 7 . 5 1 7 . 8
Aldrin 1*25 5*6 68 4*0 1 0 . 1 1 4 . 1 A i d r in 0*50 5*6 100 1 5 . 3 1 1 . 6 26 . 9
1 / Gamma isomer* Heads per stem based on 10 stems per plot; other data on 2 heads per plot replicated 5 times* Table ID*- The effect of different insecticides, applied to red clover as dilute dusts on September 12, 1950, on the population of the clover root borer in August 1951* Croton, Ohio*
Active ingredient Roots Total Average Reduction in Seed yields Treatment per acre infested borers per root population per acre Pounds Percent Number Number Percent Bushels
None - 56.0 260 . 3.5 - 3.4
Aldrin 1.75 5.3 5 0.1 96.1 3.6
Chlordane 4.00 9.3 25 0.3 90.4 3.1
BHC 1.251/ 26.7 74 1.0 71.5 3.3
Lindane 1.2$ 34.7 114 1.5 56.1 3.1
16.5 101.0 L.S.D.t e n 19*19 9 a 2/ 25.9 141.7
1/ Grama isomer* 2/ Not significait* - 25 - In untreated plots, 56 percent of tile roots were Infested compared
with 5*3 and 9*3 for plots treated with aidrin and chlordane. Technical
BHC and lindane were less effective averaging 2 6 , 7 and 34*7 percent Infested roots, respectively* Aid Tin effected the greatest population
reduction of 9 8 , 1 percent followed by chlordane, technical BHC and
lindane with 90*4, 71*5, and 5 6 , 1 percent, respe 2tiveily. Seed yields ware determined for each treatment by harvesting the
heads from 4 samples, one—fourth square yard In area, from each plot on
September 5-6, 1951* The samples were passed through a small seed
thresher and the resulting seed through a mall vacuum—operated seed
cleaner* While the differences in seod yields did not prove to be
significant It is Interesting to note that plots treated with aldrin which showed the highest population reduction also had the highest yield
of 3*6 bushels per acre* The other treatments' ranged from 3*1 to 3*4 bushels per acre (table 10)*
Plots treated May 4. 1951*— Aldrin at 1.5 and 1*75 pounds per acre, heptachlor at the same dosages, and per thane at 4*0 pounds were applied
May 4 to a aeries of plot3, 25 x 25 feet, arranged in a randomized block,
replicated 4 times, Heptachlor and perthane had not previously been tested for root borer control. All of these materials were applied as
1 percent du3ts using the hand-operated fertilizer spreader. Samples of
15 roots per plot or 60 roots per treatment were dug and dissected on
August 22* The data are shown in table 13.* Table 11#- The effect of various insecticidal applications applied Hay 1, 1951 on the population of the clover root borer in August, 1951*
Active ingredient Roots Total Average Reduction in Seed yields Treatment per acre infested borers per root population per acre Pounds Percent Number Number Percent Bushels
None 46.4 236 3.9 - 3.5
Heptachlor 1.50 8.3 6 0.1 97.4 2.3
Heptachlor 1.75 0.0 0 0.0 100.0 3.1
Aldrin 1.50 13.3 19 0.3 91.9 3.1
Aldrin 1.75 1.7 3 0.05 98.7 2.8
Perthane 4*0 25.0 79 1.3 66.5 3.6
T * n 19:1 19.1 U9.4 99:1 26.4 165.1 No infested roots were found in the sample dug from the plots
treated with heptachlor at 1*75 pounds per acre* In samples from plots
treated with this insecticide at 1.5 pounds per acre, 3.3 percent of the
roots were infested, compared with 43*4 percent in untreated plots*
Aldrin at 1*75 and 1*50 pounds per acre averaged 1*7 and 13*3 percent of
the roots infested. Perthane wa3 much less effective averaging 25*0 per
cent infested roots. Keductiens in the root borer population of 1 0 0 . 0 ,
97*4* 9®.7* 91#9. and 66.5 percent were recorded in plots treated with
heptachlor at 1*75 pounds per acre, and at 1.5 pounds, aldrin at 1 . 7 5 and 1 . 5 pounds, and perthane at 4.0 pounds.
The heads from four samples, one—fourth square yard in area, were harvested from each plot on September 10. These samples were threshed and cleaned to determine the seed yields. The yields ranged from 2.3
to 3m6 bushels per acre. Considerable variation in seed yields was observed but the differences did not prove to be significant (table 1 1 ) .
Comparison of sorava and dusts for clover root borer controls- Large plots of Kenland rod clover near Delaware, Ohio were used to compare the effectiveness of aldrin and technical BHC when applied as sprays and dusts. The plots were 60 x 200 feet in sise, replicated 4 times. All of the materials were applied on May 2, 1951 using a tractor-drawn fertiliser spreader for the dusts and a power sprayer mounted on a pickup truck for the sprays. Samples of roots were dog and dissected on August
6, taking 6 samples of 3 roots each per plot. The results of the tests are given in table 12. Table 12.- Comparative effectiveness of dusts and sprays of aldrin and technical BHC applied Nay 2, 1951 on the population of the clover root borer in August 1951* Delaware, Ohio.
Active ingredient Boots Total Average Reduction in Seed yields Treatment per acre infested borers per root population per acre Pounds Percent Number Number Percent Bushels
None - 37.5 112 1.6 - 3.9
BHC dust 1*9 1 / 9.7 12 0.2 B9.3 3.8
BHC spray 1*8 i/ 36.1 99 1*4 H . 6 3.9
Aldrin dust 1*9 7.0 6 0.1 92.8 3.6
Aldrin spray 1*8 8*4 6 0.1 94.6 3.6
16*6 77.4 L.S.D.L S D 19,199tl 23.3
1/ Gamma isomer*
Note* A sample of 36 roots dug in an adjacent area unaffected by drift averaged 53 percent of the roots infested and 2*7 borers per root* - 29 - All of the material a were highly effective except technical BHC
when applied as a spray. Population reductions of 94*6 percent were
obtained with aldrin spray, 9 2 . 8 percent with aldrin du3t, 89*3 percent
with, technical BHC dust, and 11*6 percent with BHC spray. Reasons for
the poor showing of technic al BHC applied a3 a spray are not understood,
Xn studies made in 1950 effective control was obtained with sprays of
this insecticide*
On August 22, the heads from 6 samples, one—fourth square yard in
area, were harvested from e *ch plot and threshed to determine the seed
yields. Little variation was noted among the various treatments which
averaged from 3*6 to 3*9 bushels per acre (table 12)#
TESTS CONDUCTED DURING 1 9 5 1 - 5 2 Tests during 1951—52 to control the clover root borer were continued with the emphasis being placed on sprays. Both fall and spring applica tions were evaluated. Tests with insecticide—fungicide combinations
were also made to explore the pos sib ill tie 3 of controlling clover root
diseases#
Plots treated Septaaber 20. 1951*— At Croton, Ohio plots of red
clover 25 x 25 feet in size arranged in a Latin square were treated on
September 20, 1951 with heptachlor at 1#75 pounds per acre, aldrin at
1*75 pounds, BHC at 1*75 pounds of the gamma isomer, and chlordane at
4#0 pounds per acre* All rpf the materials were applied as emulsion sprays using hand equipment* During July 28— 29, 1952, a sample of three roots from each of 5 locations or 15 roots per plot (75 roots per treat ment ) were dug and dissected to determine the effectiveness of the - 30 -
treatments* The data are listed in table 13• None of the treatments were very effective, Heptachlor and aldrin censed population reductions
of 44-*5 and 32*1 percent. Chlordane and BHC were not effective in these te sts*
The stand of cl over was too poor to obtain adequate seed yield s,
but 4 stems were harvested from each plot on August 19 and the number
of seeds per head calculated. None of the treatments had any effect on
the number of seeds per head a3 shown in table 13*
Plots treated Hay 1. 1952*— Plots of red clover 25 x 25 feet arranged
in a Latin square were treated at Croton, Ohio with emulsion sprays of heptachlor at 1*5 and 1*0 pounds per acre, isodrin at 0*75 pound, and
dleldrin at 0*75 pound* The materials were applied with hand equipment on May 1* Samples of 15 roots per plot, or 75 roots per treatment, were dug and dissected July 3*^-A u g u s t 4 to determine the root borer population*
The clover heads from a sample of 4 stems per plot were harvested on
August 19 to determine any effect on the muriber of seeds per head.
Table 14 presents the results of this test*
As in the fall treatments, none of the sprays were too effective.
Heptachlor at 1*5 pounds per acre and at 1*0 pound reduced the root borer population 44*1 and 40*7 percent, respectively* Dleldrin effected a reduction of 23*2 percent, vhereas isodrin was not effective at the dosage used. Plots treated with heptachlor at 1*0 and 1*5 pounds per acre averaged 32*2 and 31**’ seeds per head compared with 27*7 for untreated plots* Plots treated with isodrin and dleldrin averaged 26*6 and 27*8 seeds per head, respectively* Table 13 •- The effect of different insecticides, applied to red clover as emulsion sprays on September 20, 1951, on the population of the clover root borer in July, 1952* Croton, Ohio*
Active Average ingredient Roots Total Average Reduction in seeds Treatment per acre infested borers per root population per head Founds Percent Number Number Percent Number
Untreated - 86*7 476 • 6.3 m 37.0
Heptachlor 1.75 58,7 264 3.5 44.5 23.5
Aldrin 1.75 66.7 323 4.3 32.1 27.4
BHC 1.75 ^ 86.7 469 6.3 1.3 17.9
Chlordane 4# 00 86.7 541 7.2 412.6 21*4
19:1 18.3 176.2 L.S.D* 99*1 25.6
\j Gama. isomer* Table The effect of different insecticides, applied to red clover as emulsion sprays on Hay 1, 1952, on the population of the clover root borer in August, 1952* Croton, Ohio.
Active Average ingredient Roots Total Average Reduction in seeds Treatment per acre infested borers per root population per head Pounds Percent Ntufcer Runtoer Percent Number
Untreated - 77.3 388 5.2 - 27.7
Heptachlor 1*5 52.0 217 2.9 44.1 31.4
Heptachlor 1*0 58.7 230 3.1 40.7 32.2
Isodrin 0.75 82.7 489 6.5 426.0 2b Js
Dleldrin 0.75 62.7 298 4.0 23.2 27.8 - 33 - Large plot tests*— At Delaware, Ohio, plots of Ken land red clover
63 x 350 feet arranged in a randomized block replicated 4 tines were
sprayed May 2 with heptachlor at 1*75 pounds per acre, aldrin at 1*75
pounds, and BHC at 1*75 pounds of the gamma isomer* These plots were
treated with a power sprayer mounted on a pickup truck* Samples of 15
roots per plot, or 60 roots per treatment, were dug and dissected on
August 6* The heads from 4 stems per plot were harvested August 20,
threshed, and the seeds counted to determine the seeds per head* The
data are listed in table 15* Heptachlor caused a reduction in the root borer population of 6C.4
percent compared with 30*0 for BHC and 12*9 for aldrin* Plots treated with heptachlor averaged 56*9 seeds per head compared with 39*9 for untreated plots* Plots treated with dilute dusts*- To secure some data on the compara
tive effectiveness of dusts, plots of red clover, in the same field as those described above, were treated with dilute dusts of aldrin, hepta—
chlor, and BHC at the same dosages as applied in spray form in the tests described above* The plots were 30 x 30 feet in size arranged in a Latin
square* The materials were applied as 1 percent dusts on May 3 using a hand-operated fertilizer spreader* On August 5 a sample of 15 roots per plot, or 60 roots per treatment, were dug and dissected to evaluate the effectiveness of the treatments* A seed sample consisting of the heads from 4 stems per plot was harvested on August 20 and threshed to deter mine any effect on seed production* Table 16 presents the data from these tests* Table 15*- The effect of different insecticides, applied to red clover as emulsion sprays on Kay 2, 1952, on the population of the clover root borer in August, 1952. Delaware, Ohio*
Active Average ingredient Boots Total Average Reduction in seeds Treatment per acre infested borers per root population per head Pounds Percent Number Nustoer Percent Nuntoer
Untreated - 81.7 349 . 5.8 - 39.9
Heptachlor 1.75 53.3 138 2.3 60.4 56.9
Aldrin 1.75 73.3 304 5.1 12.9 44.0
BHC 1.75 ^ 63.3 244 4.1 30.0 31.0
L.S.D. 19:1 Not significant. 99*1 y Gama isomer. Table 1 6 . - The effect of different insecticides, applied to red clover as dilute dusts on May 3» 1952, on the population of the clover root borer in August, 1952* Delaware, Ohio.
Active Average Ingredient Roots Total Average Reduction in seeds Treatment per acre infested borers per root population per head Pounds Percent Number Number Percent Number
Untreated - 85.0 482 . 8.0 - 23.7
Heptachlor 1.75 13.3 3 0.05 99.4 38.6
Aldrin 1.75 35.0 80 1.3 83.4 37.8
BHC 1.75 y 36.7 92 1.5 80.9 39.8
19*1 30.7 152.7 L.S.D. 99:1 44.1 219.4 y Gamma isomer. - 36 - All of the dusts were more effective than sprays. Heptachlor was somewhat more effective than the other materials causing a reduction in population of 9 9 * 4 percent. Aldrin and BHC reduced the population 83*4 a n d 8 0 * 9 percent, respectively* The reasons for the sprays being less effective than dusts are not known. Results with sprays in previous years have been encouraging but have not been consistent in their effect*
It is possible that applications with low pressure sprayers applying 5—6 gallons of solution per acre will not be effective* Using a larger volume of water might improve the results*
Clover heads harvested from the treated plots averaged more seeds per head than heads from untreated plots. Plots treated with heptachlor, aldrin and BHC averaged 38,8, 37*8, and 39*8 seeds per head compared with 23*7 for untreated plots* The effect of combining a fungicide with clover root borer treat ments.— Some tests were made to determine whether certain clover root diseases could be controlled by adding a fungicide to the more promising insecticides for rqot borer control. The fungicide used was compound 162
(hexachlorocyclopentadiene) at 20 pounds per acre in combination with aldrin at 1*75 pounds, and with heptachlor at 1*75 pounds. These insecticides without a fungicide were also included in the tests. The materials were applied as emulsion sprays to plots 20 x 20 feet in size arranged in a Latin square. Two experiment s were conducted, one treated on November 9, 1 9 5 1 , and another on April 28, 1 9 5 2 . During August 1 1 — 12,
1952, a sample of 15 roots per plot, or 75 roots per treatment, were dug and dissected to determine the root borer infestation and disease condi— tions* The roots were classed as shewing disease and also as to the
degree of discoloration using a scale of 0 to 10* The disease readings
were made by Dr* Keimit Kreitlow, pathologist,, Bureau of Plant Industry,
Soils, and Agricultural Engineering and A* T* Schmitthenner, pathologist at the Ohio Agricultural Experiment Station*
Table 17 gives the data from the plots treated Novenfcer 9» 1951* Aldrin alone reduced the root borer population 83*6 percent compared with
97*2 percent when combined with a fUngicide* Heptachlor was 92*0 percent
effective when used alone, 77*0 percent when combined with a fungicide* All of the roots from untreated plots showed symptoms of disease
compared with 64*0 to 97*3 percent for treated plots. The degree of dis coloration averaged 6*9 for untreated plots, 2*7 for aidrin plus a fungicide, 4*1 for aldrin alone, 4*3 for heptachlor with a fungicide, and
4*1 for heptachlor alone* In table 18, the results from the plots treated on April 28 are
given* None of the materials were as effective against the clover root
borer as the same materials a p p l i e d in Novenber, Aldrin was not effec
tive against the root borer in these tests, but aldrin plus a fungicide
gave a reduction in population of 61*0 percent* Heptachlor effected a
reduction in population of 7 6 * 8 percent vhen used alone and 73*7 percent
when combined with the fungicide* Roots from the treated plots averaged from 9 0 * 7 to 97*3 percent of the roots showing disease qymptoms compared with 9 6 * 7 percent of the roots in untreated plots* The degree of discoloration was lees in the treated plots, but the addition of a fungicide had little, if any,addi
tional effect* Table 17#- The effect of aldrin and heptachlor, alone and combined with a fungicide, applied to plots of red clover on November 9, 1951, on the population of the clover root borer and the incidence of clover root diseases in August, 1952# Columbus, Ohio.
Active ingredient Roots Total Average Redaction in Disease Treatment per acre infested borers per root population Discoloration : Degree Pounds Percent Number Nunber Percent Percent
Untreated - 66.7 213 2.84 - 100.0 6.9
Aldrin + 1.75 6 84.0 Compound 162=/ 20 #0 9.3 0.06 97.2 2.7
Aldrin 1.75 30.7 35 0.47 83.6 93.3 4.1
Heptachlor +. , 1.75 Compound 162=/ 20.0 26.7 49 0.65 77.0 93.3 4.3
Heptachlor 1.75 17.3 17 0.23 92.0 97.3 4.1
1/ Hexachlorocyclopentadiene. Note: The degree of discoloration is based on a scale of 0 to 10# Table 1 8 . - The effect of aldrin and heptachlor, alone and combined with a fungicide, applied to plots of red clover on April 28, 1952, on the population of the clover root borer and the incidence of clover root diseases in August, 1952* Columbus, Ohio.
Active ingredient Hoots Total Average Reduction in Disease Treatment per acre infested borers per root population Discoloration : Degree Pounds Percent Number Number Percent Percent
Untreated 64.0 190 2.5 m 98.7 5.9
Aldrin + . , 1.75 Compound 162=' 20.0 34.7 74 1.0 61.0 94.7 4.7
Aldrin 1.75 50.7 172 2.3 9.5 97.3 5.1
Heptachlor + , 1.75 Compound 16 2 » 20.0 30.7 50 .7 73.7 93.3 3.9
Heptachlor 1.75 32.0 44 .6 76.8 90.7 4.0
y Hexachlorocyclopentadiene. Notes The degree of discoloration is based on a scale of 0 to 10, - 40 -
INSECTICIDE RESIDUES ON CLOT EH FORAGE
In June of 1951 and 1952 samples of clover forage were cut to
determine the residues present on the hay crop* In each plot, two
samples of approximately 1 , 0 0 0 grams green weight were cut and air dried*
These samples were submitted to the Division of Insecticide Investiga
tions, Bureau of Entomology and Plant Quarantine for chemical analysis*
Clover treated with different insectic idee on September 12, 1950 and
sampled June 7 , 1951 contained 0*20 to 1*2 parts per million residues*
Samples from plots treated May 4, 1951 and cut June 7 contained residues of 0*32 to 5*6 p*p*m* The latter figure Is high due to one sample that
contained a very high residue* Other samples from the same treatment contained only negligible amounts* The conclusion of the chemists was
that measurable amounts of insecticide did not exist on these samples*
The data are summarized in table 19* Somewhat higher residues were obtained in 1952 (see table 2 0 )*
Samples of forage from plots treated in Septenber 1951 shewed from 0*1
to 21*4 p*p*m* residue in June 1952* Forage from plots dusted or sprayed on May 1—2, 1952 and cut June 4—6 showed residues of 1*4 to 12*8 p*p*m*
Much more data are needed on the residues following treatments for the
clover root borer before any conclusions can be reached* 41
Table 1 9 . — Insecticide residues on red clover forage treated for control of the clover root borer 1950—51. Columbus, Ohio*
Rate Date Date Material per acre sprayed sampled Residue Pounds PPM
Aldrin dust 1 . 7 5 9 / 1 2 / 5 0 6 / 7 / 5 1 0 . 3 6 BHC ii 1 . 2 5 1 / 9 / 1 2 / 5 0 6 / 7 / 5 1 1 . 5 6
Lindane tf 1 . 2 5 9 / 1 2 / 5 0 6/7/51 0 . 2 0 Chlordane II 4 . 0 0 9 / 1 2 / 5 0 6 /7 / 5 1 1 . 2 0
Aldrin dust 1 . 7 5 5 /4/ 5 1 6 / 7 / 5 1 5.65 2 / Heptachlor it 1.75 5/4/51 6/7/51 2.02 Perthane n 4 . 0 0 5/4 / 5 1 6 / 7 / 5 1 0 . 3 2
BHC ii 1 . 9 1 / 5/4/51 6/7/51 0 . 9 8
1 / Gramma isomer. 2/ High residue caused by one of 4 samples with 1 6 . 7 PPM* Other samples of same treatment calculated 1*3* 2*6* and 0*0 p*p*m* - 4 2
Table 20*— Insecticide residues on red clover forage treated for control of the clever root borer 1951— 52* Colunbus, Ohio*
Rate Date Date Material per acre sprayed sampled Residue Pounds PPM
Heptachlor emulsion 1*75 9/20/51 6/4/52 0*5
Aldrin « 1,75 9/20/51 6/4/52 0.1 BHC « 1*75 y 9/20/51 6/4/52 8.8 Chlordane •* 4*00 9/20/51 6/4/52 2L.4
Heptachlor emulsion 1*5 5/1/52 6/4/52 6*7 " " 1,0 5/1/52 6/4/52 7.0
Isodrin " 0,75 5/1/52 6/4/52 1*4
Dleldrin " 0,75 5/1/52 6/4/52 2,4
Heotachlor emulsion 1.75 5/2/52 6/6/52 5*1 « dust 1.75 5/2/52 6/6/52 12.8
BHC emulsion 1.75 1/ 5/2/52 6/6/52 6.4 BHC dust 1*75 y 5/2/52 6/6/52 10*1 Aldrin emulsion 1*75 5/2/52 6/6/52 7*2 Aldrin dust 1*75 5/3/52 6/6/52 4.2
1/ Gamma Isomer DISCUSSION OF RESULTS As a result or these studies it has been shown that the clover root borer can be controlled by the newer organic insecticides. The most promising materials and dosages are aldrin at 1.75 to 2*0 pounds, hepta^- chlor at 1*75 to 2*0 pounds and benzene hexachloride at 1*5 to 2*0 pounds of the gasna isomer per acre* From the information to date dusts appear to be more effective than emulsion sprays, but more data on sprays are needed* Tests using larger amounts of water might prove more encouraging* These studies showed that it is practical to apply the dilute dusts with a grain drill or fertilizer distributor* In this way eijqpensive dusting equipment would not be necessaiy*
More data are needed on the effect of root borer control on the seed yields of red clover. Differences obtained in the presents tests proved not to be significant but clover in areas where the root borers were controlled showed a tendency to produce more heads per stem and more seeds per head than clover in untreated areas* Considerable variation was found in the insecticide residues present on clover forage following treatment for the clover root borer indicating that this phase of the problem needs further study* The relationship between the clover root borer and clover root diseases was only superficially studied. More data on the use of fungicides lx>th alone and in combination with insecticides would be necessary to furnish conclusive data* - 44 -
EFFECT OF THE HOOT BORER TREATMENTS ON THE POPULATION OF THE MEADOW SPITTLEBUG
Very early In the course of these investigations it was noted that
plots treated for root borer control were practically free of infesta tion by the meadow spittlebug Philaenus leucophEhalmua CL*) an important pest of clover and other legume forage* Data on the infestation by spittlebug nymphs have been taken in all of these experiments. The
various plots were sampled by using a heavy ./Ire rod 3& inches long and marked In five places with red paint* The rod was dropped at random and the spittlebug masses and nymphs were counted on the stem nearest each red mark*
1949-50 Plots*— Counts made M^r 23 in a series of plots at Croton,
Ohio treated with dilute dusts of aldrin, technical BHC, and chlordane on
Septe.nber 29, 1949 showed all of them except chlordane provided effective spittlebug control* The infestation in the check plots was much less than an untreated area of the same field Indicating some effect of drift* The data are given in table 21 * Another set of plots at Croton was treated May 2 with BHC, lindane, chlordane, parathion, and aldrin* All of the materials except parathion were applied at two different dosages. Counts made in these plots on
May 23 showed no spittlebug infestation In any of the treated plots. Untreated plots averaged 1*2 percent of the stems infested but an un treated area in the same field unaffected by drift averaged 50*4 percent*
In another set of plots treated May 11 to compare sprays and dusts of BHC, aldrin, and chlordane for root borer control no spittlebug nymphs were found in any of the treated plots* As in other root borer experi— 45
Table 21*— Spittlebug nymphs on 12 5 stems of red clover on May 23# 1950 in plots treated for control of clover root borer on September 29# 1949* Croton, Ohio*
Active ir^j re client Treatment per acre Total nymphs Reduction Pounds fJuaber Percent
Untreated - 10 -
Aldrin 1*5 1 90.0 BHC 1.0 0 100*0
Chlordane 3.0 5 50.0 BHC y 1.0 2 80.0
1/ Formulated from material containing 98 percent gamma isomer* A count of 125 stems made in a part of this field unaffected by drift showed 63 nymphs* - 46 -
ments only a very light population was present in the untreated plots
showing some effect of drift* The application of dilute dusts for root borer control by means of
a grain drill was tried on larger areas at Groton, Ohio* On May 3*
1 acre waa treated with 100 pounds of technical BHC dust containing
1 percent of the gamma isomer, 1 acre with 100 pounds of a 1 percent
aldrin, 0*4 acre with 200 pounds of 1 percent chlordane, and 1 acre left
untreated. Spittlebug counts were made in this area on May 23 by
examining 250 stems at random in each treatment. All of the materials
gave excellent control of spittlebug nymphs. No infestation could be
observed in the area treated with BHC while an extremely light population
was recorded in the aldrin sample* In the area treated with chlordane
no nymphs were taken in the sample, but a very light infestation was noted in the plots* Untreated areas averaged 46*4 percent of the stems infested and 1*2 nymphs per stem. The data are given in table 22* At Delaware, Ohio, two areas were treated for root borer control using a new type fertilizer spreader that covered a strip of clover
10 feet wide. On May 4 about 0*5 acre was treated with BHC at 100 pounds
of a 1 percent gamma isomer dust per acre and 0*5 acre with aldrin at 200 pounds of a 1 percent dust per acre* On May 25» 125 stems were
examined in each of the areas and also in an untreated portion of the
same field* No spittlebug infestation was found in either the BHC or
aldrin treatment s whereas the untreated area averaged 43*2 percent of
the stems infested and 1*0 nymphs per stem* 47
Table 22#— Spittlebug nymphs on 250 stems of red clover on May 24* 1950 from areas treated with insecticides applied by means of a grain drill on May 3* 1950 to control the clover root borer# Croton, Ohio#
Approximate Active ingredient Total Treatment acreage applied per acre nymphs Reduction Pounds Number Percent
Untreated .6 - 303 - BHC 1.0 1.0 o 100#0
Aldrin 1*0 1.0 1 99.7
Chlordane 0.4 5.0 0 1/ 100*0 i/ Infestation noted* - 46 -
1950"51 Plots#— On May 22, 1951* 5 samples of 5 stems each were
examined in each of* the plots treated on Septenter 12, 1950# All of the treatments, except chlordane (table 2 3 ) were highly effective against
the spittle bug. Technical benzene hexachloride was most effective reducing the population 98.6 percent, follcwed by aldrin, lindane, and
chlordane reducing the population 98#1, 92.6 and 76*5 percent, respec tively#
Plots 25 x 25 feet in a randomized block replicated 4 times were used to test aldrin at 1#50 and 1*75 pounds per acre, heptachlor at the same strengths, and per thane at 4#0 pounds# The materials were applied
May 4, 1951 using the fertilizer spreader as in the fall tests. Spittle— bug population counts were taken May 22*
No infestation was recorded in the sanples taken in the treated plots. Untreated plots averaged 77 percent of the stems infested, 0*65 mass per stem, and 1*56 nymphs per stem*
Near Delaware, Ohio, plots 60 x 200 feet replicated 4 times were used to compare sprays and dusts of aldrin and technical benzene hexa— chloride for root borer control* The dusts were applied with a tractor- drawn fertilizer spreader and the sprays were applied using a power sprayer mounted on a pickup truck# The materials were applied May 2 and spittlebug counts were taken May 15* In each plot 20 samples of 5 steins each were examined. The data showed that either technical benzene hexa— chloride or aldrin when applied as sprays or dusts in strengths sufficient to control the clover root borer will also control the meadow spittlebug. The data are in table 24* Table 23*- The effect of clover root borer treatments applied September 12, 1950 on the population of the meadow spittlebug in May 1951* Groton, Ohio*
Reduction in Rate Stems Masses Nymphs Infested Treatment per acre infested per stem per stem stems Masses Nymphs Pounds Percent Number Number Percent Percent Percent
Untreated i / - 69.6 .70 1.62 - - -
Aldrin 1.75 3.2 .03 .03 95.4 95.7 98.1 O CM BHC 1.25 g.i. 1.6 .02 • 97.7 97.1 98.8
Chlordane 4.0 29.6 .31 .38 57.5 55.7 76.5
Lindane 1.25 7.2 .06 .12 89.6 88.6 92.6
1/ An additional sample in this field unaffected by drift showed 90*0 percent of the
stems infested, and an average of 0*94 niass and 2*8 nymphs per stem* 50 «
Table 21+*— Effect of sprays and dusts of aldrin and technical benzene hexachloride applied to control the clover mot borer on the population of the meadow spittlebug. Delaware, Ohio, 1951*
Hate Steins Masses Nymphs Treatment per acre infested per stem per stem Pound3 Percent Number Number
Untreated 45. S 0.52 0.72 BHC spray 1,8 g.i. 0,0 0.00 0.00
BHC dust 1*9 g.i* 0,0 .00 .00
Aldrin spray l.a 0,0 + .00 + .00 +
Aldrin dust 1*9 0,0 .00 .00 1951—52 Plots,— On September 20, 1951 at Croton, Ohio, a 5 x 5 Latin square with plots 25 x 25 feet in size was used to test sprays of aldrin^ dieldrin, chlordane, and heptachlor as a control for the clover root borer# A count of 25 stems per plot on May ZL revealed that all of the treatments had caused more than a 70 percent reduction in spittlebug nymphs# Heptachlor at 1#75 pounds and technical BHC at 1*75 pounds of the gamma isomer per acre were the most effective averaging population reductions of 90*7 and 89#3 percent, respectively# The data are given in table 25* On Msy 1 plots of red clover 25 x 25 feet arranged in a Latin square were sprayed with heptachlor at 1*5 pounds and 1#0 pound, dieldrin and compound 711 each at 0*75 pound per acre* Data taken May 21 by examining 25 stems per plot showed that all of them were very effective as spittle— hug controls. The data are listed in table 26*
Near Delaware, Ohio, 0*25 acre plots were treated with a power sprayer on May 2 using technical BHC at 1*75 pounds of the gamma isoner, aldrin at 1*75 pounds, and heptachlor at 1*75 pounds per acre* All treatments were replicated 4 times. On May 22, 10 samples of 5 stems each were examined in each plot and the spittle bugs reuorded* All of these root borer treatments very effectively controlled the spittlebug*
The data are presented in table 27* Table 25.- The effect of clover root borer treatments applied September 20, 1951 on the population of the meadow spittlebug in May 1952* Croton, Ohio*
Reduction in Rate Stems Masses Nymphs Infested Treatment per acre infested per stem per stem stems Masses Nymphs Pounds Percent Number Number Percent Percent Percent
Untreated am 63.2 •82 • 1*64 - - -
Aldrin 1.75 23.6 •28 •AB 59.5 66.0 70.7
BHC 1.75 i/ 13.6 .14 *18 78*5 83.5 89.3
Chlordane 4*00 20.8 •23 .31 67.1 71.8 81.0
Heptachlor 1.75 H . 4 *14 .15 77.2 82.5 90.7
1/ Gamma isomer* Note: Examination of 100 stems in an area of this field unaffected by drift showed 62 percent of the stems infested averaging 0*74 masses and 2.2 nymphs per stem* Table 26#- The effect of clover root borer treatments applied May 1, 1952 on the population of the meadow spittlebug. Croton, Ohio.
Reduction in Rate Stems Masses Nymphs Infested Treatment per acre infested per stem per stem stems Masses Nymphs Pounds Percent Number Nunber Percent Percent Percent
Untreated - 60.8 •82 • 1.81 - - «e
Heptachlor 1.5 0,8 .01 .01 98.7 99.0 99.6
Heptachlor 1.00 3.2 .03 .03 94.7 96.1 98.2
Dieldrin 0.75 0.0 •00 .00 100.0 100.0 100.0
Isodrin 0.75 2.4 .02 .03 96.0 97.0 98.2
Note: Examination of 100 stems in an area of this field unaffected by drift shewed 62 percent of the stems infested averaging 0*74 masses and 2.2 nymphs per stem. Table 27*- The effect of clover root borer sprays applied to l/4-acre plots using power equipment on the population of the meadow spittlebug, Delaware, Ohio, 1952*
Reduction in Rate Stems Uasses Nymphs Infested Treatment per acre infested per stem per stem stems Uasses Nymphs Pounds Percent Number Number Percent Percent Percent
Untreated 41.0 .35 • .44 - - -
Heptachlor 1.75 0.0 •0 .0 100.0 . 100.0 100.0
BHC 1.75 y 0.0 .0 .0 100.0 100.0 100.0
Aldrin 1.75 2.0 ♦02 •02 98.0 98.0 98.0
1/ Gama isomer.
Note: A check of 50 stems in an untreated area of this field showed 44 percent of the stems infested with an average of 0*5 mass and 0*6 nymph per stem* - 55 -
Aa a comparison with sprays a few plots were dusted at Delaware on
Kay 3 using the same materials and dosager per acre as in the spray plot s* The dusts were applied May 3 with a hand—opsrated fertilizer
spreader to plots 30 x 30 feet arranged in a 4 x 4 Latin square* A count of 25 stems per plot on May 22 showed that all of the root borer dusts
practically eliminated the spittlebug* Insecticides alone and in combination with the fungicide were
applied as sprays to plots 20 x 20 feet arranged in a 5 x 5 Latin square* Two experiments, one treated on November 9, 1951 and one on April 28, 1952, were conducted* Examination of 25 stems per plot in each experi ment were made on Kay 7—6*
Table 28 shows the spittlebug data from the fall treatments* The control of the spittlebug on these tests was poorer than in most root
borer experiment 3. These treatments were purposely delayed until after freezing weather and since the large majority of spittlebug adults were
dead it was not believed that these tests would control the adults and
thus affect oviposit!on* Table 29 shows the data from applications applied April 28, 1952*
Nearly perfect control was obtained with heptachlor alone and ccsibinea with a fungicide, and with aldrin plus a fungicide* Aldrin alone was only slightly less effective averaging a population reduction of 94*4 percent. Table 2 8 , - The effect of insecticide-fungicide combinations for clover root borer control applied November 9* 1951 on the population of the meadow spittlebug in May 1952* Columbus, Ohio*
Reduction in Rate Stems Masses Nymphs Infested Treatment per acre infested per stem per stem stems Masses Nymphs Pounds Percent Number Nunber Percent Percent Percent
Untreated - 52.0 •64 • .96 - --
Aldrin 1.75 and 11.2 .11 .U 78.5 82.5 88.3 Compound 162 20.00
Heptachlor 1.75 and 36.0 .48 .56 30.8 25.0 41.7 Compound 162 20.00
Aldrin 1.75 20.0 •26 .35 61.5 60.0 63.3
Heptachlor 1.75 15.2 .15 .18 70.8 76.2 81.7 Table 2 9 . - The effect of in sect ici de-fungicide combinations for clover root borer control applied April 28, 1952 on the population of the meadow spittlebug in May 1952* Columbus, Ohio*
Reduction in Rate Steins Hasses Nymphs Infested Treatment per acre infested per stem per stem stems Masses Nymphs Pounds Percent Number Number Percent Percent Percent
Untreated - 40.0 •5 0.86
Aldrin 1.75 M l and .8 .01 .01 93.0 98.5 99.1 Compound 162 20*00
Heptachlor 1.75 and •6 .01 .01 98.0 98.5 99.1 Compound 162 20*00
Aldrin 1.75 4.8 .05 .05 88.0 90.9 94.4
Heptachlor 1.75 •8 .01 .01 98.0 98.5 99.1 - 58 -
SUMMARY
Studies on the control of the clover root borer were conducted in Ohio from 1947—1952. During this period sprays or dusts of benzene
hexachloride, chlordane, DDT, aldrin, dieldrin, parathion, methoxychlor,
toxaphene, lindane, heptachlor, perthane, and isodrin were tested. Of
these materials BHC, aldrin, and heptachlor appear most promising. The
results of 1947-49 tests have already been published and only the 1949— 52 results are presented in detail*
Tests with dusts applied September 29* 1949 showed that aldrin at 1.5 pounds per acre and gamma BHC at 1*0 pound reduced the root borer population 64 and 54 percent. BHC from 98 percent gamma material at 1*0 pound and chlordane at 3»0 pounds were ineffective. Plots treated
May 2, 1950 with dusts of various insecticides showed that chlordane at
5*0 pounds per acre reduced the population 87 percent and at 3 pounds
71 percent. Parathion at 5*0 pounds, EHC at 1*0 and 0*75 pound of the gamma isomer were ineffective. Data from the 1949— 50 tests indicated that the dosages were too low for effective; control* Another test on
May 11 to determine the comparative effectiveness of sprays and dusts indicated that either might furnish aderuate control. Two tests, in which the materials were applied with a grain drill and a tractor-drawn fertilizer distributor showed that either of these farm implements are satisfactory for applying the dusts. Seed yield data from the 1949— 50 experiments were not significant but some of the treatments tended to have more heads per stem and seeds per head than untreated plots* - 59 - In plots treated Septesfcer 12, 1950 dusts of aldrin at 1*75 pounds per acre, chlordane at 4*0 pounds, gamma BHC and lindane at 1*25 pounds per acre reduced the population 96, 90 , 72, and 56 percent* In spring
tests applied May 4, 1951* heptachlor at 1*75 and 1*5 pounds per acre, aldrin at 1*75 and 1*5 pounds, and perthane at 4*0 pounds effected reduc
tions of 100, 97 , 99 , 92, and 66 percent, respectively* In a test to
compare sprays and dust3 applied Kay 2, aldrin at 1*9 pounds per acre as a spray reduced the population 93 percent and at 1*8 pounds as a dust
95 percent, BHC as a dust at 1,9 pounds of the gamma isomer per acre reduced the population 69 percent and as a spray at 1*8 pounds 12 percent*
Seed samples from the 1950—51 tests did not show significant yield differences although some of the treatment3 outyielded the check plots*
In plots treated with emulsion spr^rs of heptachlor at 1*75 pounds, gamma BHC at 1*75 pounds and chlordane at 4*0 pounds per acre on
September 20, 1951, very poor root borer control was obtained* Plots sprayed May 1, 1952 with heptachlor at 1*5 and 1*0 pounds showed a population reduction of 44 and 41 percent, Dieldrin at 0*75 pound and isodrln at 0*75 pound were not effective. In larger replicated plots treated with a power sprayer on May 2, 1952 with heptachlor at 1*75 pounds, aldrin at 1*75 pounds and BHC at 1.75 pounds of the ganma isomer poor results were obtained* Heptachlor was most promising with a popula tion reduction of 60 percent. Smaller plots in the same field treated with dusts of these materials at the same dosages on May 3 showed reduc tions of 99, 63, and 81 percent for heptachlor, aldrin, and BHC, respectively* Seed samples taken for yield showed that clover from some - 60 - of t-he treated plots produced more seeds per head than from untreated plots, but the data were not significant#
Confcining a fungicide with heptachlor, aldrin, or BHC did not reduce the number of diseased clover roots but did reduce the degree of dis coloration in the roots# Insecticide residues on clover forage as determined in 1951 ranged from 0*20 to 5*65 p#p*m* and in 1952 from 0#10 to 21 #4 p.p*m* More data on this phase of the problem are needed before conclusions can be drawn#
Data taken in each of the experiments from 1949-52 showed that any of the materials that effectively controlled the clover loot borer also controlled the meadow spittlebug, another important clover pest* - 61 -
LITERATURE CITED
App, B. A* 1950* Surface applications of insecticides to control the clover root borer. Thesis for the M.S. degree Ohio State University 1950*
App, B. A. and Ray T. Everly, 1950. Insecticide dusts to control the clover root borer and the meadow spittlebug, USDA BEPQ E—811 Mimeo. December* Eedel, L* 1888. Faune des col£opt£res du bassin de la Seine. VI: 385— 421.
Chamberlin, V«r. J. 1939* The bark and tinker beetles of North America. Oregon State College Coop* Ass*n* 1939*
Chapuis, F. 1869, Synopsis des scolytides. Me. Roy. Soc. Sci. Liege 3* 213—269. (Reference not seen. Noted in Zool. Record C, page 283. 1869*)
Davis, G. C. 1894* Insects of the clover field. Part I. Insects destructive to clover* Mich. Agr. Expt* Sta. Bui. 116: 41-^47* Everly, Ray T. and App, B. A. 1949* Control of the clover root borer, Hylastinus ob3curus (Marsh.) Proc. Ind. Acad* Sci. 58: 151- 1952*
Folsom, J. W. 1909* The insect pests of clover and alfalfa. HI. Agr. Expt. Sta. Bui. 134: 113-197. Gibson, A, 1913* Report on insects for the year 1912. Ottawa District Ann. Rept. Ent. Soc. Ont. Toronto 1913» PP* 11—17. Guercio, G. del. 1915* Ulterior! richeiche sullo stremenzimento o incappucciamento del trlfoglio. Redia 10: 235-301* Hagedorn, M. 1910. Coleoptorum catalogus. Pars, 4 Ipidae page 7.
Hudson, H. F. 1926. Notes on the life history of the clover root borer* 56th Ann. Rept. Ent. Soc. Ont. 1925, pp. 92-93.
Lincoln, C. G. 1942. 55th Rept. Cornell Agric. Expt. Sta*
Lintner, J. A. 1879* Two pests of the clover plant, Hylesinus trifolii Mull., and Cccidomyia legumlnicola Lintn. Cultivator and Country Gentlemen 44: 631. October 2.
Marshall, D. S., Newsom, L. D», Gyrisco, George G., and Schwardt, H. H* (1949) Control of the clover root borer. Jour* Ec. Ent* 42: 2, 315-318* - 62 -
Mar sham, T. 1802* Entomologia Britannica, sis tens insecta Britanninae indigena, secundum methodum Linnaeanam disposita* (Reference not seen* Noted in Bibliotheca Entomologica by H. A* Hagen, page 521*) Mills, Harlw B* 1941* Montana insect pests* Mont. Bull. 384 January*
Moanette, G. F* 1917* Three insects affecting clover seed production* Ore. Agrlc. Coll* Corvallis, Ext. Bull* 203*
Mueller, P. W, J. 1807* Avi3 sur une esp£se de bostriche qui detruit les racincs du trefle des pr€s, (Reference not seen. Noted in Bibliotheca Entomologica by H, A* Hagen, page 557*)
Portnan, R. W*, and Barr, W. F* (1952) Pests in Idaho* Idaho Ext* Cir, 122* August* Riley, C* V, 1879* The clover root borer. Comm, of Agri. Rept. 1878: 2^8- 250*
Rockwood, L, P, 1926* The clover root borer. U* S* Dept, of Agri, Dept. Bui. 1426* Schmitt, 1844. Entwicklung^geschichte des Hylesinus trifolii Muller* Ent. Zeit. 5: 369-387* Schwardt, H, H. and Lincoln, C. G. 1941* Entomology and Limnology* 54th Rept. Cornell Agri. Expt. Sta, pp* 127—138#
Shull, W, E . 1944* Idaho recommendations for insect control. Idaho Bull. 252. March. Sorenson, C. J. 1936* Contribution to a symposium on the biology of Utah. Principal insect pests of cereals, forage, and orchard fruits in Utah. Proc. Utah Acad* Sci* 13* 2L9—223* Stear, J. R, 1918. The clover root borer. Ohio Mthly. Bull. Ohio Agri* Expt. Sta. 30: 187-189* Stookey, E. B* 1920* Why does red clover fail* Mthly* Bull* West, Wash. Expt. Sta* Puyallup 8:. 18—20* Swain, J. M. 1913* The economic importance of Canadian Ipidae* Proc# Ent. Soc. Brit. Col. Vist*, B. C# 3 N.S. pp. 41-43* . 1918* Canadian bark beetles. Part II. A preliminary classification, with an account of the habits and means of control* Can* Dept. Agri* Ent. Er. Bui* 14* - 63 - Webster, F. M. 1899* The clover root borer. Ohio Agr. Expt. Sta. Bui. 112: 143-149* . 1905. The clover root borer. U. S. Dept. Agri. Bur. Ent. Circ. 67* _ , 1910# The clover root borer. U. S, Dept# Agri. Eur. Ent# Circ. 119* 64
AUTOBIOGRAPHY
I, Bernard Auman App, was born in Elgin, Illinois, on December 18,
1906* I attended grammar and high school in this city, I received the Eachelor of Arts degree from the University of Illinois in June,
1930, Since 1930 I have held various assignments as an entomologist in the Bureau of Entomology and Plant Quarantine of the United States
Department of Agriculture, From 1930—34 I was engaged in research
3tudies on the European corn borer in Ohio, During 1935—36 I conducted studies on the corn insects of Puerto Rico, From 1937—48 I was employed In research studies on the white—fringed beetle. Since 1948 I have been engaged in research on legume insects. Studies from 1948-53 were made at the Legume Seed Laboratory maintained cooperatively by The Ohio State University and the United States Department of Agriculture, I received the Master of Science degree from The Ohio State University in 1950 and completed the requirements for ths degree Doctor of Philosophy in 1953*