Insect Pest Management in Virginia Cotton, Peanut, and Soybean

Table 65. Mean number of larvae per 3-ft beat cloth sample and percent control 1 , PT11-CEW-3 (Mike Grizzard farm,
Southampton Co., VA). Tidewater AREC, Suffolk, VA, 2011. Insecticide treatments were applied on August 16.
Aug 18 2 Aug 22
# Material Rate
Small
larvae
Medium
larvae
Large
larvae
Total
larvae
Small
larvae
Medium
larvae
Large
larvae
Total
larvae % control
1 DiPel ES (Kur.) 1 pt 2.25 5.00 b 2.00 b 9.25 b 0.00 b 1.25 0.00 c 1.25 b 65.9
2 Karate Z 1.28 oz 1.50 2.75 b-d 1.50 b 5.75 bc 0.25 b 1.25 0.25 c 1.75 b 75.6
3 Karate Z 1.92 oz 2.25 2.00 cd 2.25 b 6.50 bc 0.25 b 1.00 1.50 bc 2.75 b 69.9
4 DiPel ES (Kur.)
+ Karate Z
5 DiPel ES (Kur.)
+ Karate Z
1 pt
1.28 oz
1 pt
1.92 oz
1.00 3.75 b-d 0.50 b 5.25 bc 0.50 b 2.50 1.25 bc 4.25 b 69.1
2.75 4.00 bc 1.75 b 8.50 bc 1.00 b 0.75 2.50 ab 4.25 b 58.5
6 Baythroid XL 2.4 oz 0.50 1.25 d 1.50 b 3.25 c 0.00 b 1.75 0.50 c 2.25 b 82.1
7 Brigade 2EC 5.12 oz 1.50 2.50 b-d 1.50 b 5.50 bc 0.25 b 1.75 1.25 bc 3.25 b 71.5
8 Untreated 5.00 11.00 a 5.00 a 21.00 a 3.25 a 3.25 3.25 a 9.75 a ---
LSD NS 2.69 2.27 5.57 1.01 NS 1.69 3.28 ---
Means within a column followed by the same letter(s) are not significantly different (Protected LSD, P=0.05).
1 Percent control is based on cumulative larval days (CLD) in the treatment relative to the untreated control. CLD’s are calculated with the following equation:
Σ (X i+1 – X i )[(Y i + Y i+1 )/2], where X i and X i+1 are adjacent sample dates and Y i and Y i+1 are corresponding points of total larvae per 3-ft beat cloth sample.
There were 61.5 CLD’s in the untreated control.
2 Larval numbers were multiplied by 2 in the untreated control on August 18.