Karla Emfinger

Verifying an F1 screen for identification and quantification of rare Bacillus thuringiensis resistance alleles in field populations of the sugarcane borer, Diatraea saccharalis

Using an F1 screen, 352 feral individuals of the sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), were examined for the presence of Bacillus thuringiensis (Bt)‐resistance alleles. These insects represented four geographical populations collected in central and northeastern Louisiana, USA, and one field population from the Gulf Coast area of Texas, USA, during 2006. The F1 screen used various crosses between field‐collected insects and a laboratory strain of Cry1Ab‐resistant D. saccharalis, including both reciprocal crosses and group mating. F1 neonates of the crosses were screened for Bt resistance on Bt maize leaf tissue. One field‐collected individual of D. saccharalis was shown to have a Bt‐resistance allele. Based on Bayesian analysis procedures, the Bt‐resistance allele frequency in the five populations of D. saccharalis was 0.0028 with a 95% confidence interval of 0.0003–0.0079. The successful identification of a resistance allele in a field collection of insects suggests that the F1 screening technique could be an effective tool for detecting and monitoring rare Bt‐resistance alleles in field populations of D. saccharalis.

Evaluation of Selected Insecticides for Control of Stink Bugs in Soybean, 2014

The efficacies of selected insecticides were evaluated against a stink bug complex at the Macon Ridge Research Station (Franklin Parish). Soybeans were planted onto a Gigger silt loam soil on 4 Jun. Plot size was four rows (40-in. on centers) × 40 ft. Treatments were placed in an RCB design with four replications. Insecticides were applied on 3 Sep with a John Deere 6000 tractor and compressed air system calibrated to deliver 10 GPA …

EVALUATION OF INSECTICIDE EFFICACY AGAINST SOYBEAN LOOPER IN SOYBEANS, 2010

A field trial evaluated selected foliar treatments against soybean looper (SBL) on R5.5 stage soybeans at the Macon Ridge Research Station (Franklin Parish). Soybean seed were planted into a Gigger-Gilbert silt loam soil on 15 Apr. Plot size was four rows (40inches on centers) X 45 ft. Treatments were arranged in a RCB design with four replications. Insecticides were applied with a highclearance sprayer and compressed air system calibrated to deliver 6 gpa through TeeJet TX-8 hollow cone nozzles (2/row) at 50 psi. Insecticides were applied on 13 Aug, and post-treatment evaluations were performed at 3, 7 and 11 DAT. Insecticide efficacy was measured by taking 25 sweep-samples with a sweep net (15 inches diameter) in each plot and recording the number of SBL larvae > 1⁄2 inch. Data were subjected to ANOVA and means separated according to DNMRT. Total rainfall of 0.76 inches occurred during the trial period.

EVALUATION OF RADIANT (SPINETORAM) EFFICACY AGAINST THRIPS ON SEEDLING COTTON, 2009

Selected foliar insecticides were evaluated for control of thrips on cotton seedlings at the Macon Ridge Research Station (Franklin Parish). Cotton seed were planted into a Gigger-Gilbert silt loam soil on 21 Apr. Plot size was four rows (40-inches on centers) X 50 ft. Treatments were placed in a RCB design with four replications. Insecticides were applied with a hand boom and compressed air system calibrated to deliver 10 gpa through TeeJet 8015 flat fan nozzles (2/row) at 32 psi on 20 May. Insecticide efficacy was measured by randomly selecting 10 plants per plot and counting the number of thrips (immatures and adults) at 2 DAT (22 May), 5 DAT (25 May), 7 DAT (27 May) and 13 DAT (2 Jun). Plant samples were processed using whole plant washing procedures to remove thrips. Thrips were counted using a dissecting microscope. Data were subjected to ANOVA and means separated according to DNMRT. Total rainfall of 1.66 inches occurred during the test.

EVALUATION OF SELECTED INSECTICIDES FOR CONTROL OF SOYBEAN LOOPER AND STINK BUG, 2007

Selected insecticides were evaluated for control of SBL and a stink bug complex (SBC) in two tests at the Macon Ridge Research Station (Franklin Parish). Soybean seed (Asgrow 5501) were planted into a Gigger silt loam soil on 11 Jun in Tests 1 and 2. Plot size was four rows (40-inches on centers) x 50 ft. Treatments were placed in a RCB design with four replications in both tests. Insecticides were applied on 21 Aug in Test 1 and 27 Aug in Test 2 with a John Deere high clearance sprayer and CO2-charged system calibrated to deliver 6 gpa through Teejet TX-6 hollow cone nozzles (2/row) at 48 psi. Treatment efficacy against SBL and SBC was determined at 2, 6, and 9 DAT in Test 1 and 2, 4, and 8 DAT in Test 2 using a standard (15 inches diameter) sweep net and taking a 25 sweep sample in each plot. Data were subjected to ANOVA and means separated according to DMRT. No rainfall occurred during these tests.

EVALUATION OF FOLIAR INSECTICIDE EFFICACY AGAINST THRIPS ON SEEDLING COTTON, 2007

Selected foliar insecticides were evaluated for control of thrips on cotton seedlings at the Macon Ridge Research Station (Franklin Parish). Cotton seed were planted into a Gigger-Gilbert silt loam soil on 7 May. Plot size was four rows (40-inch centers) X 25 ft. Treatments were placed in a RCB design with four replications. Foliar insecticides were applied with a handboom and compressed air system calibrated to deliver 10 GPA through TeeJet 8001 flat fan nozzles (2/row) at 20 psi on 25 May and 4 Jun. Insecticide efficacy was measured by randomly selecting 10 plants per plot and counting the number of immatures and adults on 28 May (3 DAT1), 1 Jun (7 DAT1), and 7 Jun (3 DAT2). Plant samples were processed using whole plant washing procedures to remove thrips. Thrips were counted using a dissecting microscope. Seedling damage was estimated visually using a 0-5 rating scale with 0 as no damage and 5 representing severe damage. Seedling damage was evaluated on 4 Jun (10 DAT1) and 13 Jun (9 DAT2). Data were subjected to ANOVA and means separated according to DMRT. Total rainfall of 4.95 inches occurred during the test.

EVALUATION OF SELECTED SEED TREATMENTS FOR CONTROL OF CHINCH BUGS ON FIELD CORN, 2003

The efficacy of seed treatments against chinch bugs in field corn un eve*** Field corn seed (Dekalb 697) were planted into a Gigger silt loam soil on 21 Mar at the Macon Ridge Research Station. Plot size was 4 rows (centered on 40 inches) × 35 ft. Treatments were replicated four times within a RCBD design. Treatments were commercially applied to the seed. Plots were planted with a John Deere 7300 Series row crop planter modified with manual delivery seed hoppers. Granular at-planting insecticide treatments were applied with the conventional granular application hoppers and T-Banding attachments. The percentage of plants infested with chinch bugs and number of chinch bugs were determined by examining 10 plants per plot at 45, 58, and 62 days after planting (DAP). Data were subjected to ANOVA procedures and means separated according to Duncans new multiple range test (P ≤ 0.05). A total of 4.10 inches of rainfall occurred from planting until the end of sampling.

EVALUATION OF SELECTED INSECTICIDE TREATMENTS AGAINST HELIOTHINES ON COTTON, 2002

Cotton seed were planted 4 Jun in plots consisting of four rows (centered on 40 inch) x 50 ft. Treatments were arranged in a RCB design and replicated four times. Insecticides were applied with a John Deere 6000 hi-clearance sprayer and CO2 charged system calibrated to deliver 6 gpa through Teejet TX-8 hollow cone nozzles (2/row) at 46 psi. Insecticides were applied on 2, 6, and 9 Aug. Treatments were evaluated by examining 100 flower buds (squares) per plot on 6, 9, and 13 Aug, for evidence of Bollworm (BW) and Tobacco budworm (TBW) damage and squares infested with larvae. The test received 1.40 inch of rain between the first insecticide application (2 Aug) and the last sampling date (13 Aug). Data were analyzed with ANOVA, and means were separated according to DMRT.

EVALUATION OF SELECTED FOLIAR INSECTICIDES AGAINST THRIPS ON SEEDLING COTTON, 2001

Cotton seed were planted into a Gigger-Gilbert silt loam soil on 20 Apr at the Macon Ridge location of the Northeast Research Station. Plot size was 4 rows (40 inches) 20 ft. Treatments were arranged in a RCB design with four replications. Insecticides were applied on 14 May with a John Deere 5400N tractor and compressed air system calibrated to deliver 10 gpa through Teejet 80015 flat fan nozzles (two/row) at 35 psi. Numbers of thrips adults and immatures were measured by randomly selecting 10 plants per plot at 2, 4, and 7 DAT. Plant samples were processed using whole plant washing procedures to remove thrips. Insects were counted using a dissecting microscope. Data were subjected to ANOVA and means separated according to DMRT. No rainfall was recorded during this test.