I '. *
K F C *l t 'II
Pasture Insect Control
John R. Strayer
Assistant Extension Entomologist
Probably the most important pests of pasture
grasses in Florida are spittlebugs, aphids, and
caterpillars. Other insects may become important
at certain times in localized areas. This circular
covers some of these pests, recommending the
best current controls considering, of course, the
insecticide residue problem.
Aphids.-The yellow sugarcane aphid (Figure
1) is a major pest of pangolagrass. It is a poten-
tial threat in all areas growing pangolagrass but
is of greatest importance in central and southern
Florida. The greenbug (also an aphid) is found
in most areas, but unlike the yellow sugarcane
aphid, it is highly parasitized and frequently con-
trolled by natural enemies.
Armyworms.-(Fall, southern, striped, others).
-These caterpillars or "worms" are the imma-
ture stages of grayish-brown moths. Females lay
their eggs on the lower leaves of grasses and the
larvae begin to feed as soon as they hatch. Be-
cause they often move in large numbers from one
area to another in search of food, they are called
armyworms. Usually only one damaging genera-
tion occurs per year. For successful control and
to prevent extensive damage treatment must be
made when the worms are small. The almost
mature larvae (1 to l1/2 inches) are difficult to
Grassworms or Striped Grass Loopers (several
kinds).-These caterpillars, when full grown, are
longer and more slender than the armyworms
discussed earlier. They move in a looping manner
by humping their bodies. Striped grass loopers
(Figure 2) are especially fond of pangola and
para grasses. Their color varies from cream to
blue-gray to brown, black or orange. Large black
and white spots appear when the body of the
larva is fully extended. In addition to this colora-
tion, grassworms have a light narrow stripe along
the middle of the back the full length of the body.
Smaller larvae are often overlooked.
Spittlebugs.-Spittlebugs have caused damage
to pastures in some areas of Florida. Adults, as
well as nymphs, damage plants by sucking plant
sap. The adult spittlebug is about 38-inch long,
and is dark brown to black, with two orange-red
lines across its wings (Figure 3). The presence
of immatures or nymphs is easily determined be-
cause they are covered with a mass of froth or
spittle-like material (Figure 3). The spittlebug
nymph is shown in Figure 4.
Tests for control have been limited, but toxa-
phene, Sevin or phosdrin should result in a good
kill of these pests when applied to grass short
enough for the insecticide to get down to where
insects are feeding. Insecticides have not given
PASTURE INSECT CONTROL CHART
Insect Material Amount/Acre Restrictions and Remarks
Aphids 15% parathion WP or 1-2 lbs. The amount of insecticide per acre varies
Several Species 1% parathion dust or 20-30 lbs. with the height and density of the grass.
40% TEPP (liquid) or Yz pint DO NOT apply parathion within 7 days, or
5% malathion dust or 20-30 lbs. TEPP within 2 days, or phosdrin within
25% malathion WP or 2-4 Ibs. 1 day of grazing by dairy or beef animals.
25% phosdrin EC or 1-2 pts. No waiting period for malathion.
2% phosdrin dust 15-25 lbs.
Armyworms 10% toxaphene dust or 15-20 lbs. DO NOT graze dairy cattle on toxaphene
Grass loopers 40% toxaphene WP or 3-4 lbs. treated pastures. Allow at least 7 days
Other caterpillars 5% Sevin dust or 20-30 lbs. between applications of toxaphene and
80% Sevin sprayable or 114-2 lbs. grazing by beef animals. DO NOT apply
2% phosdrin dust or 20-25 lbs. parathion within 7 days or phosdrin within
25% phosdrin EC or 1 quart 1 day of grazing by dairy or beef animals.
2% parathion dust or 15-20 lbs. There is no time limitation for grass
15% parathion WP 2 lbs. treated with Sevin or malathion for dairy
or beef animals.
Spittlebugs Same as for Army Worms See Discussion in Text
Spider mites Demeton (Systox) 2 EC or 1-1 pint Minimum interval between last application
(on clover) 15% parathion WP or 1-2 lbs. of demeton and harvest or grazing should
1% parathion dust 20-30 lbs. be 21 days. DO NOT apply parathion with-
in 7 days of grazing dairy or beef animals.
WP = Wettable powder
EC = Emulsifiable concentrate
effective control where the grass has been allowed
to grow tall and become densely matted. Burning
off the dense mat of dry grass in late February
or early March has been suggested for control of
spittlebugs in Coastal bermuda pastures in the
central and northern areas of the state. If the
pasture contains clover, it can be burned late in
Recent observations suggest that mowing or
grazing often enough to keep down the dense mat
will reduce the spittlebug problem. The dense
mat retains moisture which is needed for spittle-
Spider mites (on clover).-Spider mites cause
damage to clover pastures in some areas and re-
quire control measures. Research has shown
demeton (Systox) at 1/2 to 1 pint per acre of the
emulsifiable concentrate (containing 2 lbs. active
ingredient per gallon) to be the most effective.
Minimum interval between last application and
harvest or grazing should be 21 days. Two appli-
cations of parathion 1 to 2 weeks apart (as for
aphids on control chart) can be used for controll-
ing mites on clover. Note the restrictions for
parathion in the control chart.
Insect infestations in pastures usually start in
small, isolated areas. Make frequent inspections
and spot treat before infestations become wide-
spread. This practice not only saves insecticide,
but also prevents extensive injury to the grass
and reduces the residue problem. Recommended
materials are listed in the Insect Control Chart.
The use of insecticides not recommended, or in
dosages greater than those recommended, may
result in insecticide residues in excess of legal
tolerances. If the dosages recommended in the
chart are exceeded, the minimum time between
last application and harvest or grazing specified
in the chart is not applicable and a longer inter-
val should be allowed.
To avoid danger of milk contamination with
insecticide residues, use only the recommended
materials and observe the restrictions. Many
insecticides are labeled for other uses on pasture
and forage crops. Dairy cows when allowed to
graze on forage or pasture having residues, store
these residues in their body fat. Later the cows
will secrete these residues (or their metabolic
products) in their milk. Calves, heifers or dry
cows store these insecticides in the liver, body fat,
and other vital organs and will secrete them in
their milk after freshening.
Insecticides are poisonous to man and animals
and should be handled according to the pre-
cautions given on the label. TEPP, parathion,
demeton (Systox), and phosdrin are especially
Remember, always use recommended insecti-
sides according to label directions and tolerance
restrictions. Read the insecticide label carefully
and completely before opening the container, and
observe all precautions. Do not contaminate feed
and water. Store insecticides in the original
labeled containers out of reach of children, pets,
and livestock, and away from food or feed. Dis-
pose of empty containers promptly and safely.
Appreciation is expressed to various research scientists
of the Institute of Food and Agricultural Sciences for
information included in this publication. Appreciation is
also expressed to E. W. Beck, Entomology Research
Division A.R.S., Tifton, Georgia, for the spittlebug photo-
graphs used in this publication.
The use of trade names in this publication is solely for
the purpose of providing specific information. It is not
a guarantee or warranty of the products named, and does
not signify that they are approved to the exclusion of
others of a suitable composition.
COOPERATIVE EXTENSION WORK IN
AGRICULTURE AND HOME ECONOMICS
(Acts f May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida
United States Department of Agriculture, Cooperating
"i-O. Watkips, Director