Title: Evaluation of Contact and Residual Activity of Selected Insecticides for Control of Rice Stink Bug. Beaumont, TX. 2001. Principal Investigator: M.O. Way Texas A&M University Agricultural Research and Extension Center 1509 Aggie Drive Beaumont, TX 77713 409.752.2741 (phone) 409.752.5560 (fax) moway@aesrg.tamu.edu (email) Introduction The rice stink bug (RSB), Oebalus pugnax, is a key pest of rice in Texas. USEPA may prohibit use of organophosphates and carbamates in the future. This means rice farmers may lose currently registered RSB insecticides containing carbaryl and methyl parathion. Thus, other potential RSB insecticides must be evaluated for efficacy. The objective of this experiment is to evaluate selected insecticides for contact and residual activity against the RSB. Materials and Methods Two experiments were conducted at the Texas A&M University Agricultural Research and Extension Center at Beaumont in 2001. Experiment1: This experiment was designed to evaluate the effectiveness of the treatment insecticides applied directly to adult RSB. Adult RSB were collected at the Beaumont Center on 28 Sep by sweep net from untreated rice. Insects were placed in ventilated plastic tubes which were transported to the greenhouse. In the greenhouse, 10 adult insects were placed inside a cylindrical metal screen (1/4 inch mesh) cage which was 1 inch tall and 7 5/8 inches in diameter. Each cage with 10 RSB was a replication and each treatment consisted of four replications. Treatments are described in the tables. The screen cages with insects were sprayed with the treatment insecticides on 28 Sep with a three nozzle (tip size 800067, 50 mesh screens), hand-held spray rig pressurized with CO 2 (20-30 psi). Spray swath was about 4 ft and final spray volume was 28.8 gpa. Insects were allowed to dry for 1 hour then each group of insects in each cage was transferred to four untreated rice panicles whose severed ends were inserted in moist sand in a styrofoam cup. The panicles were in the dough stage of development. A transparent, ventilated plastic cylinder was placed over the RSB-infested panicles. This plastic cylinder served as a cage once the bottom was inserted in the sand and the top fitted with a fine mesh organdy cloth. Number of dead insects was recorded 24 and 48 hours after application of treatment insecticides. Experiment 2: This experiment was designed to evaluate the effectiveness of the treatment insecticides applied indirectly to adult RSB by caging the insects on panicles sprayed in the field. Plots were laid out in a randomized complete block design in an untreated rice field (Cocodrie) in the dough stage of development. Each plot was 20 ft x 4 ft (seven rows, 7 inches between rows). 66
Treatments described in the tables were replicated four times. On 11 Sep, plots were sprayed with the treatment insecticides with a three nozzle (800067 tip size, 50 mesh screens), hand-held spray rig pressurized with CO 2 (20-30 psi). Spray width was about 4 ft. Final spray volume was 28.8 gpa. One, 4, 7, 10 and 14 days after application, four panicles were randomly removed from each plot. Immediately after removal, severed panicles were transported to a greenhouse. Each set of four panicles was caged in a transparent plastic cylinder ventilated with screen windows and a screen top. The severed ends of panicles were inserted in moist sand contained in a styrofoam cup. The bottom of the cage was secured in the moist sand. Once panicles and cages were in place, each cage was infested with 10 adult RSB collected by sweep net from untreated ratoon crop rice. At 24 and 48 hours after infestation, cages were inspected for dead insects. For both experiments data were expressed as % mortality which was transformed using arcsine. Transformed data were then analyzed by 2-way ANOVA and means separated by DMRT. Additional Materials and Methods for rice production practices for Experiment 2: 17 May drill-planted Cocodrie @ 90 lb/acre 18 May at planting urea applied by hand @ 2/3 of 170 lb N/acre, incorporated with a rake and flushed 26 May rice emerged through soil (League) 9 d after planting; from emergence to permanent flood, plots flushed as needed 14 Jun Arrosolo 3-3E @ 2 qt/acre, Basagran @ 1.5 pt/acre, Facet 75DF @ 0.5 lb/acre and Agridex @ 1 pt/acre applied with a 13 nozzle, two-person spray rig (tip size = 80015, 50 mesh screens, swath width = 21.7 ft, final spray volume = 12.3 gpa) pressurized with CO 2 @ 20-30 psi 15 Jun permanent flood (20 d after emergence) 3 Jul panicle differentiation urea applied by hand @ 1/3 of 170 lb N/acre (thus, 170 lb N/acre applied during entire growing season) Results Experiment 1: Due to consistently lower than expected values in replication IV (Tables 1 and 2), results from three (and not four replications) are analyzed and interpreted. Forty-eight h after treatment, the Orthene, Karate Z, F0570 (Fury), and the high rate of GF-317 treatments provided over 90% contact control of RSB (Table 8). Experiment 2: The Orthene treatment gave the best residual control; 7 d after treatment over 30% mortality was recorded (Tables 5 and 9). At 10 d after treatment, none of the test insecticides provided control (Tables 6 and 9). Karate Z, Fury and the high rate of GF-317 treatments provided 20-30% control 1 d after treatment (Tables 3 and 9). In the future, field and lab/cage residual activity tests should be conducted simultaneously. If field tests show longer activity than lab/cage tests, then insecticidal repellency may be involved. 67
Table 1. Contact activity (24 h after treatment) of selected insecticides vs rice stink bug. Beaumont, TX. 2001. % mortality (24 h after treatment) Description [lb (AI)/acre] I II III IV 0 a Karate Z 0.030 80 70 100 80 82.5 ab F0570 0.8EC 0.017 80 70 60 70 70.0 ab F0570 0.8EC 0.021 40 87.5 90 22.2 59.9 b V-10101 2.25EC 0.090 25 11.1 50 11.1 24.3 c V-10101 2.25EC 0.180 90 60 80 10 60.0 b Orthene 97PE 0.750 100 70 100 70 85.0 a GF-317 0.003 = 3.37 g (AI)/ha 50 62.5 90 70 68.1 ab GF-317 0.006 = 6.73 g (AI)/ha 60 70 77.8 44.4 63.1 b Untreated - 0 0 0 0 0 d % mortality (24 h after treatment) Description [lb (AI)/acre] I II III 0 a Karate Z 0.030 80 70 100 83.3 ab F0570 0.8EC 0.017 80 70 60 70.0 b F0570 0.8EC 0.021 40 87.5 90 72.5 ab V-10101 2.25EC 0.090 25 11.1 50 28.7 c V-10101 2.25EC 0.180 90 60 80 76.7 ab Orthene 97PE 0.750 100 70 100 90.0 a GF-317 0.003 = 3.37 g (AI)/ha 50 62.5 90 67.5 b GF-317 0.006 = 6.73 g (AI)/ha 60 70 77.8 69.3 b Untreated - 0 0 0 0 d a Means in a column followed by the same or no letter are not significantly different at the 5% level 68
Table 2. Contact activity (48 h after treatment) of selected insecticides vs rice stink bug. Beaumont, TX. 2001. % mortality (48 h after treatment) Description [lb (AI)acre] I II III IV 0 a Karate Z 0.030 100 80 100 80 90.0 a F0570 0.8EC 0.017 100 100 80 70 87.5 ab F0570 0.8EC 0.021 100 100 90 22.2 78.1 abc V-10101 2.25EC 0.090 62.5 66.7 90 11.1 57.6 c V-10101 2.25EC 0.180 90 70 90 10 65.0 bc Orthene 97PE 0.750 100 100 100 90 97.5 a GF-317 0.003 = 3.37 g (AI)/ha 70 75 90 90 81.3 abc GF-317 0.006 = 6.73 g (AI)/ha 90 80 100 44.4 78.6 abc Untreated - 10 0 10 10 7.5 d % mortality (48 h after treatment) Description [lb (AI)/acre] I II III 0 a Karate Z 0.030 100 80 100 93.3 ab F0570 0.8EC 0.017 100 100 80 93.3 ab F0570 0.8EC 0.021 100 100 90 96.7 ab V-10101 2.25EC 0.090 62.5 66.7 90 73.1 c V-10101 2.25EC 0.180 90 70 90 83.3 bc Orthene 97PE 0.750 100 100 100 100 a GF-317 0.003 = 3.37 g (AI)/ha 70 75 90 78.3 bc GF-317 0.006 = 6.73 g (AI)/ha 90 80 100 90.0 abc Untreated - 10 0 10 6.7 d a Means in a column followed by the same or no letter are not significantly different at the 5% level 69
Table 3. Residual activity (1 d after treatment) of selected insecticides vs rice stink bug. Beaumont, TX. 2001. Sample date = 1 day after treatment % mortality (24 h exposure to panicles) Karate Z 0.030 30 20 30 20 25.0 b F0570 0.8EC 0.017 10 20 40 30 25.0 b F0570 0.8EC 0.021 20 40 20 10 22.5 b V-10101 2.25EC 0.090 10 0 0 0 2.5 cd V-10101 2.25EC 0.180 10 0 0 0 2.5 cd Orthene 97PE 0.750 80 100 50 60 72.5 a GF-317 0.003 10 0 10 0 5.0 cd GF-317 0.006 0 10 20 30 15.0 bc Untreated - 0 0 0 0 0 d Sample date = 1 day after treatment % mortality (48 h exposure to panicles) Karate Z 0.030 30 20 30 20 25.0 b F0570 0.8EC 0.017 10 20 40 30 25.0 b F0570 0.8EC 0.021 40 40 30 10 30.0 b V-10101 2.25EC 0.090 10 0 0 0 2.5 d V-10101 2.25EC 0.180 10 0 0 20 7.5 cd Orthene 97PE 0.750 90 100 90 60 85.0 a GF-317 0.003 10 0 10 0 5.0 cd GF-317 0.006 0 20 20 40 20.0 bc Untreated - 0 0 0 0 0 d a Means in a column followed by the same or no letter are not significantly different at the 5% level 70
Table 4. Residual activity (4 d after treatment) of selected insecticides vs rice stink bug. Beaumont, TX. 2001. Sample date = 4 days after treatment % mortality (24 h exposure to panicles) Karate Z 0.030 0 0 0 0 0 b F0570 0.8EC 0.017 0 0 0 0 0 b F0570 0.8EC 0.021 10 0 0 0 2.5 b V-10101 2.25EC 0.090 0 0 0 0 0 b V-10101 2.25EC 0.180 0 0 0 0 0 b Orthene 97PE 0.750 40 0 40 10 22.5 a GF-317 0.003 10 0 0 0 2.5 b GF-317 0.006 0 0 0 0 0 b Untreated - 0 0 0 0 0 b Sample date = 4 days after treatment % mortality (48 h exposure to panicles) Karate Z 0.030 20 0 0 10 7.5 b F0570 0.8EC 0.017 0 0 30 10 10.0 b F0570 0.8EC 0.021 10 0 0 10 5.0 b V-10101 2.25EC 0.090 0 10 0 0 2.5 b V-10101 2.25EC 0.180 0 0 0 0 0 b Orthene 97PE 0.750 60 50 60 10 45.0 a GF-317 0.003 10 10 0 0 5.0 b GF-317 0.006 0 0 0 0 0 b Untreated - 0 0 0 0 0 b a Means in a column followed by the same or no letter are not significantly different at the 5% level 71
Table 5. Residual activity (7 d after treatment) of selected insecticides vs rice stink bug. Beaumont, TX. 2001. Sample date = 7 days after treatment % mortality (24 h exposure to panicles) Karate Z 0.030 0 0 0 0 0 b F0570 0.8EC 0.017 0 0 0 0 0 b F0570 0.8EC 0.021 0 0 0 0 0 b V-10101 2.25EC 0.090 0 0 0 0 0 b V-10101 2.25EC 0.180 0 0 0 10 2.5 b Orthene 97PE 0.750 30 10 10 0 12.5 a GF-317 0.003 0 0 0 0 0 b GF-317 0.006 0 0 0 0 0 b Untreated - 0 0 0 0 0 b Sample date = 7 days after treatment % mortality (48 h exposure to panicles) Karate Z 0.030 0 0 0 0 0 b F0570 0.8EC 0.017 0 0 0 0 0 b F0570 0.8EC 0.021 0 0 0 0 0 b V-10101 2.25EC 0.090 0 0 0 0 0 b V-10101 2.25EC 0.180 0 0 0 10 2.5 b Orthene 97PE 0.750 40 30 50 10 32.5 a GF-317 0.003 10 0 0 0 2.5 b GF-317 0.006 0 0 0 0 0 b Untreated - 10 10 0 0 5.0 b a Means in a column followed by the same or no letter are not significantly different at the 5% level 72
Table 6. Residual activity (10 d after treatment) of selected insecticides vs rice stink bug. Beaumont, TX. 2001. Sample date = 10 days after treatment % mortality (24 h exposure to panicles) Karate Z 0.030 0 0 0 0 0 F0570 0.8EC 0.017 0 0 0 0 0 F0570 0.8EC 0.021 10 0 0 0 2.5 V-10101 2.25EC 0.090 0 0 0 0 0 V-10101 2.25EC 0.180 0 10 10 0 5.0 Orthene 97PE 0.750 0 0 10 0 2.5 GF-317 0.003 0 0 0 0 0 GF-317 0.006 0 0 0 0 0 Untreated - 0 0 10 0 2.5 Sample date = 10 days after treatment % mortality (48 h exposure to panicles) NS Karate Z 0.030 10 20 10 0 10.0 a F0570 0.8EC 0.017 0 10 0 0 2.5 F0570 0.8EC 0.021 20 0 0 0 5.0 V-10101 2.25EC 0.090 0 0 0 10 2.5 V-10101 2.25EC 0.180 0 10 10 0 5.0 Orthene 97PE 0.750 0 20 30 10 15.0 GF-317 0.003 0 0 0 0 0 GF-317 0.006 0 10 0 10 5.0 Untreated - 0 0 20 10 7.5 NS a Means in a column followed by the same or no letter are not significantly different at the 5% level 73
Table 7. Residual activity (14 d after treatment) of selected insecticides vs rice stink bug. Beaumont, TX. 2001. Sample date = 14 days after treatment % mortality (24 h exposure to panicles) Karate Z 0.030 0 0 0 0 0 F0570 0.8EC 0.017 0 0 0 0 0 F0570 0.8EC 0.021 10 0 0 0 2.5 V-10101 2.25EC 0.090 0 0 0 20 5.0 V-10101 2.25EC 0.180 0 0 0 0 0 Orthene 97PE 0.750 0 0 0 0 0 GF-317 0.003 0 0 0 0 0 GF-317 0.006 0 0 0 0 0 Untreated - 0 0 0 0 0 NS Sample date = 14 days after treatment % mortality (48 h exposure to panicles) Karate Z 0.030 0 0 0 0 0 b F0570 0.8EC 0.017 0 0 0 0 0 b F0570 0.8EC 0.021 10 0 0 0 2.5 b V-10101 2.25EC 0.090 10 10 0 20 10.0 a V-10101 2.25EC 0.180 10 0 0 0 2.5 b Orthene 97PE 0.750 20 20 10 0 12.5 a GF-317 0.003 0 0 0 0 0 b GF-317 0.006 0 0 0 0 0 b Untreated - 0 0 0 10 2.5 b a Means in a column followed by the same or no letter are not significantly different at the 5% level 74
Table 8 (Summary of Tables 1 and 2). Contact activity of selected insecticides vs rice stink bug (RSB). Beaumont, TX. 2001. % mortality (h after treatment) a Treatment [lb (AI)/acre] 24 48 Karate Z 0.030 83.3 ab 93.3 ab F0570 0.8EC 0.017 70.0 b 93.3 ab F0570 0.8EC 0.021 72.5 ab 96.7 ab V-10101 2.25EC 0.090 28.7 c 73.1 c V-10101 2.25EC 0.180 76.7 ab 83.3 bc Orthene 97PE 0.750 90.0 a 100 a GF-317 0.003 67.5 b 78.3 bc GF-317 0.006 69.3 b 90 abc Untreated - 0 d 6.7 d a Means in a column followed by the same or no letter are not significantly different at the 5% level Table 9 (Summary of Tables 3-7). Residual activity of selected insecticides vs rice stink bug (RSB). Beaumont, TX. 2001. Days after treatment b Description [lb (AI)/acre] 1 a 4 a 7 a 10 a 14 a Karate Z 0.030 25.0 b 7.5 b 0 b 10.0 0 b F0570 0.8EC 0.017 25.0 b 10.0 b 0 b 2.5 0 b F0570 0.8EC 0.021 30.0 b 5.0 b 0 b 5.0 2.5 b V-10101 2.25EC 0.090 2.5 d 2.5 b 0 b 2.5 10.0 a V-10101 2.25EC 0.180 7.5 cd 0 b 2.5 b 5.0 2.5 b Orthene 97PE 0.750 85.0 a 45.0 a 32.5 a 15. 0 12.5 a GF-317 0.003 5.0 cd 5.0 b 2.5 b 0 0 b GF-317 0.006 20.0 bc 0 b 0 b 5.0 0 b Untreated - 0 d 0 b 5.0 b 7.5 2.5 b NS a Means in a column followed by the same or no letter are not significantly different at the 5% level b Mortality recorded 48 h after RSB exposed to panicles. 75