(F52) COTTON: Gossypium hirsutum L., ‘Stoneville 4793R’ EVALUATION OF INSECTICIDE EFFICACY AGAINST LATE-SEASON HEMIPTERAN PESTS ON COTTON, 2004 K. V. Tindall LSU AgCenter Macon Ridge Research Station, Winnsboro, LA 71295 Phone: (318) 435-2157 Fax: (318) 435-2133 E-mail:
[email protected] K. Emfinger B. R. Leonard J. Temple LSU AgCenter Department of Entomology 402 Life Sciences Bldg. Baton Rouge, LA 70803 Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) Southern green stink bug, Nezara viridula (L.) Brown stink bug, Euschistus servus (Say) Insecticide efficacy against tarnished plant bugs and stink bugs in cotton was evaluated at the Macon Ridge Research Station located near Winnsboro, LA. Cotton seed was planted into Gigger-Gilbert silt loam soil (pH = 6.1 and 1.1% organic matter) on 16 Jun in eight row plots (centered on 40 inches) × 50 ft. Treatments were arranged in a RCB design with four replications. Insecticides were applied on 1 Sep using a high-clearance sprayer and CO2 charged system calibrated to deliver 4.8 gpa through TX-8 hollow cone nozzles (2 per row) at 48 psi. Numbers of stink bugs and tarnished plant bugs (adults and nymphs) were determined by sampling 12-row ft of plants per plot with a shake sheet (3 × 3 ft) on 3 and 8 Sep. Data were analyzed using ANOVA and means were separated according to DMRT (P ≤ 0.05). Total rainfall of 1.2 inches occurred on 3, 4 Sep. Intruder (0.1 lb [AI]/acre), Bidrin, and Regent reduced numbers of stink bugs at 2 DAT compared to the untreated check. At 7 DAT, similar numbers of stink bugs were observed among all treatments. No insecticide treatment at either sampling date significantly reduced numbers of tarnished plant bug adults compared to that in the untreated check. All treatments except Trimax reduced the number of tarnished plant bug nymphs compared to the untreated check 2 DAT. All insecticide treatments except Trimax significantly reduced the total number of Hemipterans compared to the untreated control 2 DAT. At 7 DAT, only Bidrin and Regent continued to suppress total Hemipteran pests compared to the non-treated control. No phytotoxicity was observed with any insecticide treatment.
Tarnished plant bugs Stink bugsa Treatment/ formulation Trimax 4F Intruder 70WP Intruder 70WP Bidrin 8E Regent 4SC Untreated check P>F
Adults
Nymphs
Total hemipterans
Rate lb (AI)/acre
2 DAT
7 DAT
2 DAT
7 DAT
2 DAT
7 DAT
2 DAT
0.047 0.05 0.1 0.4 0.05 ---
4.3ab 3.3ab 1.5b 0.5b 0.5b 5.8a
2.5a 2.0a 1.8a 1.0a 0.8a 4.0a
2.3a 2.3a 0.5a 2.0a 1.5a 2.5a
2.3a 2.5a 1.5a 1.5a 1.3a 4.0a
5.0ab 3.0b 3.5b 2.0b 2.3b 7.3a
1.5a 2.5a 0.8a 1.3a 1.3a 4.0a
11.5ab 6.3ab 8.5bc 7.0ab 5.5bc 4.0ab 4.5c 3.8b 4.3c 3.3b 15.5a 12.0a
0.003
0.062
0.135
0.382 < 0.001
0.290
< 0.001
Means in a colunm followed by the same letter are not significantly different (DMRT; P > 0.05). Adults and nymphs.
a
7 DAT
0.029
