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XX. Soybean Insects
R.M.
McPherson, R.D. Hudson, and D.C. Jones
Soybeans were
harvested from 390,000 acres in 1996, an increase of 80,000 from the previous year.
Georgia's average yield in 1996 was 26 bushels per acre, down one bushel from the 1995
production. Soybean prices were up, averaging $7.50 per bushel, making the
value of the crop $76 million.*
Stink bugs were the
number one pest in Georgia soybeans in 1996. Heaviest infestations were in the
southeastern and southern parts of the state. Total losses due to this pest were
nearly $2.3 million in 1996, up slightly from 1995 levels. Control was good at most
locations, but treatments were applied late, or not at all, in some fields that were
heavily infested late in the season.
Velvetbean
caterpillar losses were also up some in 1996, costing growers nearly $1.2 million, making
this the number two pest. Caterpillar populations were later than usual and thus
damage was not as severe as expected. Insecticide control was very good for this
pest.
Lesser cornstalk
borers (LCSB) were the third most costly soybean insect pest in 1996. Economically
damaging populations of borers were primarily associated with late-planted soybeans
growing under droughty conditions. Total losses due to LCSB excceded $0.7 million,
which was about equally divided between control costs and crop damage.
Soybean looper
populations, and the resulting losses continued to be low in 1996. Total loss due to
this pest was $0.4 million, mostly due to cost of controls. Corn earworm losses were
also relatively low in 1996, totalling just over $0.2 million, about the same as 1995
losses.
All other insect
pests accounted for $215,000 in 1996. Most of these losses were due to threecornered
alfalfa hoppers, whiteflies, beet armyworms, and Mexican bean beetle. Most of these
pests were in localized or isolated areas.
*Georgia Farm Report. 1997. Volume 97. Number 4.
Estimates of Losses and Control Costs |
Rank |
Insect |
Cost of Control |
Damage |
Total |
1 |
Stink bugs1 |
$1,832,000 |
$443,000 |
$2,275,000 |
2 |
Velvetbean caterpillar |
856,000 |
338,000 |
1,194,000 |
3 |
Lesser cornstalk borer |
400,000 |
307,000 |
707,000 |
4 |
Soybean looper |
310,000 |
135,000 |
445,000 |
5 |
Corn earworm |
173,00 |
75,000 |
248,000 |
6 |
Other2 |
148,000 |
67,000 |
215,000 |
| |
Total |
$3,719,000 |
$1,365,000 |
$5,084,000 |
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1 Includes the southern green, green and brown stink bugs.
2 Others include threecornered alfalfa hoppers, whiteflies, beet armyworms, and
Mexican bean beetles. |
Information Pertaining to Control of Major Soybean Insect Pests
in Georgia in 1996 |
Insect |
No. Acres Needing Control |
No. Acres Treated |
No. of Acre Applic. |
Avg. Cost Per Unit Treated1 |
Yield Loss on Units Treated2 |
Yield Loss on Units
Untreated2 |
Stink bugs3 |
195,000 |
175,500 |
1.2 |
$8.70 |
34,000 |
25,000 |
Velvetbean caterpillar |
117,000 |
107,000 |
1.0 |
$8.00 |
19,000 |
26,000 |
Lesser Cornstalk borer |
58,000 |
47,000 |
1.0 |
$8.50 |
12,000 |
29,000 |
Soybean looper |
35,000 |
31,000 |
1.0 |
$10.00 |
8,000 |
10,000 |
Corn earworm |
23,000 |
21,000 |
1.0 |
$8.25 |
5,000 |
5,000 |
Other4 |
20,000 |
18,000 |
1.0 |
$8.25 |
4,000 |
5,000 |
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1 Includes application costs.
2 Yield units measured in bushels.
3 Includes the southern green, green and brown stink bugs.
4Others include threecornered alfalfa hoppers, whiteflies, beet armyworms,
Mexican bean beetles. |
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