Extension Circular 1567 discusses how you can control corn rootworms

Ball, Harold J.

Roselle, Robert E.

English

DigitalCommons@University of Nebraska

University of Nebraska - LincolnDigitalCommons@University of Nebraska - LincolnHistorical Materials from University of Nebraska-Lincoln Extension Extension1954EC1567 You can Control Corn RootwormsHarold J. BallRobert E. RoselleUniversity of Nebraska-Lincoln, rroselle1@unl.eduFollow this and additional works at: http://digitalcommons.unl.edu/extensionhistThis Article is brought to you for free and open access by the Extension at DigitalCommons@University of Nebraska - Lincoln. It has been accepted forinclusion in Historical Materials from University of Nebraska-Lincoln Extension by an authorized administrator of DigitalCommons@University ofNebraska - Lincoln.Ball, Harold J. and Roselle, Robert E., "EC1567 You can Control Corn Rootworms" (1954). Historical Materials from University ofNebraska-Lincoln Extension. 2700.http://digitalcommons.unl.edu/extensionhist/27005 85 f:7 1954 #:J5fo7 {!,I I E.C.l567 YOU CAN CONTROL CORN ROOTWORMS I rea ted untreated fig. 2 fig. 3 fig. 4 EXTE~SION SERVICE UNIVERSITY OF NEBRASKA COLLEGE OF AGRICULTURE AND U.S. DEPARTMENT OF AGRICULTURE COOPERATING W . V. LAMBERT, DIRECTOR \ YOU CAN CONTROL CORN ROOTWORMS By Harold J. Ball and Robert E. Roselle Three species of corn rootworms occur in Nebraska, the western (fig. 2), the northern ( fig. 3), and the southern (fig. 4). All species are dis-tributed throughout the corn growing region of the state. LIFE IITSTORY The we s t e r n and northern corn rootworm beetles lay their eggs in the soil, generally in fields which are in corn, during late summer and fall. Eggs overwinter in the soil, hatching about the time corn comes up the next spring. The small worms migrate through the soil until they contact acornroot, thenbeginfeeding. Largerroots are tunneled. and often, especially in listed corn, the worms will tunnel :i,nto the stalk. Adults of both species begin to appear about the first of July and are present until late fall. The adult of the western corn rootworm is about l/ 4 inch in length, black and yellow striped or black with a yellow tip on the abdomen. The northern corn rootworm is generally the same size or smaller and solid greenish-yellow in color. Both species feed readily onpollen, silks, and flowers of adjacent legumes and weeds. Early-emerging beetles feed on the corn leaves. The southern corn rootworm adult ((spotted cucumber beetle), spends the winter as an adult beetle hibernating in trash, crop residue, etc. Generallythe winters in Nebraska are not favor-able for overwintering adults, so they migrate into the corn growing regions from f a r t h e r south in the spring about the time corn is coming up. Eggs are laid in the soil in the spring after the corn is up. Damage to the corn is identical to that of the western and northern species. - 2 -Whe:n adults are present in large numbers the silks may be subject to continued damage by feeding. When this happens pollination may be prevented, resulting in ears with fewer kernels. C or n s i 1 k s continue growing until pollination occurs, so they would have to be chewed off for periods ~f o ne to two weeks du.cing the time pollen is produced. CONTROL Two methods of controlling corn rootworms are recommended, crop rotation and the soil application of insecticides. Crop rotation is e ffect ive against the western a nd northern corn rootworms because the eggs a re in the ground during the winter. Planting s mall grains or legumes in corn ground will s tarv e the larvae after hatching, a s they fe ed only on c orn roots. Southe r n C orn rootwor m s are not controlled with crop rotations as they lay e ggs in c orn ground a ft e r the corn is up. Clean cultivation may help prevent infe s tation. The sou the r n c orn rootworm is not a s important in Nebr aska a s the oth e r two. Soil insecticides will control the s outhern species. SOIL A PPL ICATION OF INSEC TICI DES Four insecticides are recommended as s oil treat ments . The insecticides and amounts to use are as follows : Aldrin BHC (gamma) Chlordane Heptachlor Broadcast 1 pound 1/2-1 pound 2 pounds 3/4 pound Row or Band 1/2 pound 1/2 pound 1 pound 1/2 pound - 3 -Broadcast treat ments: Broadcast treatment is probably the most effective method of appli-cation. The chemical is applied by boom type sprayer or airplane after the soil has been plowed then disked or harrowed into the soil immediately. The emulsion concentrates are easier to apply in water than are wettable powders. Row or band treatments : Row or band treat-ments are applied with a sprayer nozzle attached behind the planting shoe and in front of the cover-ing disk of the planter. The spray should be a fan t ype and adjusted to apply a spray about 18 inches in width. Fertilizer -insecticide combinations: Combi-na tion s appliedin the s p ring a t the u sual times for fertilize r applica tion h a ve given good cont rol. Careful mixing is required s o that the correct amount of insecticide i s applied per acre. These applications are probably not as depe ndable as broadcast trea tments. · Adult beetle control: Whe n infe stations are severe, and continued s ilk damage will apparent-! y occur until after pollen product ion stops, aerialapplicationof 11/2 poundsaci.ual DDTper acre is recommended. Applications after polli-nation has b een completed will be of little value in preventing further kernel loss during a parti-cular season. However, insecticidal treatme nts directed at the adults will do much towar d reduc-ing the number s of eggs deposited in the fall .. If the field i s not t o be plant ed to cor n the follow-ing year, t reatment of the adults is que sd onable. IMPORTANT INFORMATION: 1. Do not use less than recommended amounts of insecticides . - 4 -2. Do not apply on windy days, as much of the chemical will be lost. 3. Disk or harrow the chemical into the soil as soon as possible. 4. Do not use BHC in ground that will be planted to root crops during at least the next two years. 5. Applications at recommended rates will not destroy soil organisms. 6. Applications with weed killers are not recommended. 7. WARNING: Insecticides are poisons and should be used with the greatest care to avoid injury to those who handle them. Avoid excessive contact with the mat-erials. If clothes are contaminated change them immediately. Wash all ex-posed parts of the body. Do not smoke while mixing and applying insecticides. A void spray drift, working upwind from the boom. If sickness, dizziness, head-aches or other abnormal conditions occur stop operations immediately. If conditions continue, see a physician at once - take the insecticide label with you. 

EC1567  You can Control Corn Rootworms

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University of Nebraska - Lincoln
DigitalCommons@University of Nebraska - Lincoln
Historical Materials from University of Nebraska-
Lincoln Extension Extension
1954
EC1567 You can Control Corn Rootworms
Harold J. Ball
Robert E. Roselle
University of Nebraska-Lincoln, rroselle1@unl.edu
Follow this and additional works at: http://digitalcommons.unl.edu/extensionhist
This Article is brought to you for free and open access by the Extension at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for
inclusion in Historical Materials from University of Nebraska-Lincoln Extension by an authorized administrator of DigitalCommons@University of
Nebraska - Lincoln.
Ball, Harold J. and Roselle, Robert E., "EC1567 You can Control Corn Rootworms" (1954). Historical Materials from University of
Nebraska-Lincoln Extension. 2700.
http://digitalcommons.unl.edu/extensionhist/2700
5 
85 
f:7 1954 
#:J5fo7 
{!,I I 
E.C.l567 
YOU CAN CONTROL 
CORN ROOTWORMS 
I rea ted untreated 
fig. 2 fig. 3 fig. 4 
EXTE~SION SERVICE 
UNIVERSITY OF NEBRASKA COLLEGE OF AGRICULTURE 
AND U.S. DEPARTMENT OF AGRICULTURE 
COOPERATING 
W . V. LAMBERT, DIRECTOR 
\ 
YOU CAN CONTROL CORN ROOTWORMS 
By 
Harold J. Ball and Robert E. Roselle 
Three species of corn rootworms occur in 
Nebraska, the western (fig. 2), the northern ( fig. 
3), and the southern (fig. 4). All species are dis-
tributed throughout the corn growing region of the 
state. 
LIFE IITSTORY 
The we s t e r n and northern corn rootworm 
beetles lay their eggs in the soil, generally in 
fields which are in corn, during late summer and 
fall. Eggs overwinter in the soil, hatching about 
the time corn comes up the next spring. The small 
worms migrate through the soil until they contact 
acornroot, thenbeginfeeding. Largerroots are 
tunneled. and often, especially in listed corn, the 
worms will tunnel :i,nto the stalk. Adults of both 
species begin to appear about the first of July and 
are present until late fall. The adult of the western 
corn rootworm is about l/ 4 inch in length, black 
and yellow striped or black with a yellow tip on 
the abdomen. The northern corn rootworm is 
generally the same size or smaller and solid 
greenish-yellow in color. Both species feed readily 
onpollen, silks, and flowers of adjacent legumes 
and weeds. Early-emerging beetles feed on the 
corn leaves. 
The southern corn rootworm adult ((spotted 
cucumber beetle), spends the winter as an adult 
beetle hibernating in trash, crop residue, etc. 
Generallythe winters in Nebraska are not favor-
able for overwintering adults, so they migrate into 
the corn growing regions from f a r t h e r south 
in the spring about the time corn is coming up. 
Eggs are laid in the soil in the spring after the 
corn is up. Damage to the corn is identical to that 
of the western and northern species. 
- 2 -
Whe:n adults are present in large numbers 
the silks may be subject to continued damage by 
feeding. When this happens pollination may be 
prevented, resulting in ears with fewer kernels. 
C or n s i 1 k s continue growing until pollination 
occurs, so they would have to be chewed off for 
periods ~f o ne to two weeks du.cing the time pollen 
is produced. 
CONTROL 
Two methods of controlling corn rootworms 
are recommended, crop rotation and the soil 
application of insecticides. 
Crop rotation is e ffect ive against the western 
a nd northern corn rootworms because the eggs 
a re in the ground during the winter. Planting 
s mall grains or legumes in corn ground will s tarv e 
the larvae after hatching, a s they fe ed only on 
c orn roots. 
Southe r n C orn rootwor m s are not controlled 
with crop rotations as they lay e ggs in c orn ground 
a ft e r the corn is up. Clean cultivation may help 
prevent infe s tation. The sou the r n c orn rootworm 
is not a s important in Nebr aska a s the oth e r two. 
Soil insecticides will control the s outhern species. 
SOIL A PPL ICATION OF INSEC TICI DES 
Four insecticides are recommended as s oil 
treat ments . The insecticides and amounts to use 
are as follows : 
Aldrin 
BHC (gamma) 
Chlordane 
Heptachlor 
Broadcast 
1 pound 
1/2-1 pound 
2 pounds 
3/4 pound 
Row or Band 
1/2 pound 
1/2 pound 
1 pound 
1/2 pound 
- 3 -
Broadcast treat ments: Broadcast treatment 
is probably the most effective method of appli-
cation. The chemical is applied by boom type 
sprayer or airplane after the soil has been plowed 
then disked or harrowed into the soil immediately. 
The emulsion concentrates are easier to apply 
in water than are wettable powders. 
Row or band treatments : Row or band treat-
ments are applied with a sprayer nozzle attached 
behind the planting shoe and in front of the cover-
ing disk of the planter. The spray should be a 
fan t ype and adjusted to apply a spray about 18 
inches in width. 
Fertilizer -insecticide combinations: Combi-
na tion s appliedin the s p ring a t the u sual times 
for fertilize r applica tion h a ve given good cont rol. 
Careful mixing is required s o that the correct 
amount of insecticide i s applied per acre. These 
applications are probably not as depe ndable as 
broadcast trea tments. · 
Adult beetle control: Whe n infe stations are 
severe, and continued s ilk damage will apparent-
! y occur until after pollen product ion stops, 
aerialapplicationof 11/2 poundsaci.ual DDTper 
acre is recommended. Applications after polli-
nation has b een completed will be of little value 
in preventing further kernel loss during a parti-
cular season. However, insecticidal treatme nts 
directed at the adults will do much towar d reduc-
ing the number s of eggs deposited in the fall .. 
If the field i s not t o be plant ed to cor n the follow-
ing year, t reatment of the adults is que sd onable. 
IMPORTANT INFORMATION: 
1. Do not use less than recommended amounts 
of insecticides . 
- 4 -
2. Do not apply on windy days, as much of 
the chemical will be lost. 
3. Disk or harrow the chemical into the soil 
as soon as possible. 
4. Do not use BHC in ground that will be 
planted to root crops during at least the 
next two years. 
5. Applications at recommended rates will 
not destroy soil organisms. 
6. Applications with weed killers are not 
recommended. 
7. WARNING: Insecticides are poisons and 
should be used with the greatest care to 
avoid injury to those who handle them. 
Avoid excessive contact with the mat-
erials. If clothes are contaminated 
change them immediately. Wash all ex-
posed parts of the body. Do not smoke 
while mixing and applying insecticides. 
A void spray drift, working upwind from 
the boom. If sickness, dizziness, head-
aches or other abnormal conditions occur 
stop operations immediately. If 
conditions continue, see a physician at 
once - take the insecticide label with you. 


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EC1567 You can Control Corn Rootworms

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