Thrips'Module

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Thrips Management
Jack Bacheler NCSU
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Thrips Background

• Thrips (always plural) survive during the
• winter and invade cotton seedlings in the
  spring as flying adults
• They damage seedlings by piercing
• and rasping leaf and terminal tissue
• Thrips damage results in both maturity
  delays and yield
  losses
• Preventative insecticides, either seed
• treatments or at-planting insecticides,
• are needed for thrips annually

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• Major Thrips Species on
• Seedling Cotton in North Carolina
• Frankliniella fusca - tobacco thrips
• Frankliniella occidentalis - western flower
  thrips
• Neohydatothrips variabilis - soybean thrips
• Frankliniella tritici - eastern flower thrips
• Thrips tabaci - onion thrips
• L. cerealium - cereal thrips

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General Thrips Comments

• Thrips have become NCs 2nd ranked cotton pest.
• Expect seed treatments to last only
• 3 weeks following planting.
• Very early treatment, if needed, is best.
• Aim for 1st true leaf stage.
• Use combination of immature thrips
• and deformed 1st true leaf.

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Thrips Scouting and Thresholds

• Look for deformed leaves/buds
• Confirm presence of immature
• thrips.
• Inspect approx 25 seedlings
• and count number of thrips.
• Use threshold of 1 thrips / true leaf

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Thrips Control Options

• 1. Temik _at_ 5.0 lb. / acre - best overall
• returns in recent tests NC (2000 - 2004).
• 2. Gaucho Grande or Cruiser seed
• automatic foliar application good option.
• 3. Foliar application only - poor option
  except for UNR cotton.

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Control of Immature Thrips 3 wk. after
planting, Edgecombe Co., 2002
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Economic returns of at-planting options for
thrips control in NC, 2001-2004 (8 Tests)

Temik 3.20 / lb. Orthene 10.00 / lb.
Seed Trt. 7.00 / lb. _at_ 750 lbs. / acre and
0.58 / lb.
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Immature Thrips 13.1 per plant (Rocky Mount,
2001 3 weeks after planting late plants)
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Target 1st True Leaf
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Thrips Control and Returns in UNR (7.5)
CottonRocky Mount, NC 1997-1998
Value cotton _at_ 0.70/ lb Orthene2.50 (RR)
5.25 (w/o) Gaucho 27.00 Temik 35.75
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Thrips Control in UNR Cotton (7.5 rows) Wilson,
NC, 1999 (n2 tests)
Rate Thrips / Yield
Value Treatment (Prod./A) 5 plants
(Lb. lint) 0.50 0.60 0.70 Orthene
(2x) 0.25 27.6 b 638 a
312 375 439 Temik 8.0
67.6 a 744 a 348 422
497 Temik 10.0 53.5 a
718 a 329 401 473 Temik
16.0 53.3 a 759 ab 331
407 483 Check - -
52.2 a 568 b 284 341
398
Cost Cotton _at_ price / lb. Temik - 3.00/lb.
Orthene - 2.50 (RR), 5.25 (w/o)
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Thrips Levels in Conventional vs Conservation
Till Cotton (No./ plant)
a
a
a
a
No. Thrips / plant
a
a
a
a
a
a
b
a
b
b
a
b
S 97
S 00
S 01
E 00
E 01
S 02
S 03
E 04
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