Colorado Potato Beetle Control Research Articles

Colorado Potato Beetle Control with NTN 33893

Abstract Test plots were established at the UI Research and Extension Center, Aberdeen, ID. Potatoes were planted 20 May and irrigation was by fixed sprinkler sets. There were seven chemical treatments and one untreated check replicated four times in a randomized complete block design. Individual plots were 2 rows (36 inch spacing) by 25 ft. Rows were not closed at planting to facilitate hand application of the granular NTN. After insecticide application, the rows were mechanically closed. On 10 Jun foliar applications were made of NTN 240 FS and Furadan 4 F in a 4-5 inch band (20 gal/acre) over the center of the row as a broadcast spray using a CO2 pressurized backpack sprayer. On 9 Jul a second foliar broadcast application (20 gal/acre) of NTN was made on treatment 5 approximately 50 d after planting. On 25 Jun, a single application of Ambush 2 E was applied as a broadcast foliar spray (20 gal/acre) using the previously mentioned system. On a weekly basis, all stages of CPB were counted and percent defoliation estimations were made using whole plant inspections of the center five plants within the two plot rows. Larval stages were separated into small (1-3 instar) and large (4-5 instar). Data were analyzed using ANOVA and significant means separated using Newman-Keuls studentized range test.

Colorado Potato Beetle Control with Bioinsecticides, 1991

Abstract Superior' potatoes were planted 1 Mar, near Nixonton, NC, on 42 inch centers. Thimet 15 G (3.0 lb [AI]/acre) was applied in furrow at planting. Plots consisted of single rows, 10 ft long, replicated 4 times in a randomized complete block design. Alleys of 5 ft were used between replicates. Treatments were applied with a CO2 pressurized backpack sprayer with a single hollow cone nozzle (18 X). Application rate was 80 gal/acre delivered at 50 psi. Applications were made 2 May (all materials) and 9 May (MYX-1806, Trident II, and Novodor at 1 and 2 qt rates). Counts of insects on 3 hills/plot and visual damage ratings were made 9 and 14 May. Small larvae were assumed to be first and second instars, and large, third and fourth. Potatoes were harvested and yields recorded 10 Jun.

Colorado Potato Beetle Control with Natural Product Insecticides, 1990

Abstract Certified B-size seed potatoes were planted 15 May at the University of Minnesota Agricultural Experiment Station, Crookston. Plots were 4 rows wide, 15.3 m (50 ft) long, with 91 cm (3 ft) spacing between rows and 30 cm (1 ft) spacing between plants. A completely randomized plot design with 3 replications was used. Plots were scouted daily for CPB egg masses beginning 20 Jun. When egg masses were found, they were flagged and checked daily for hatch. Timing of first spray application was at 30% hatch and subequent applications on a 7 d schedule. Plots were sprayed 3 times for each generation of CPB larvae: 28 Jun, 5 and 12 Jul for first generation and 25 Jul, 2, and 9 Aug for 2nd generation. Natural product insecticides used in this experiment were Bacillus thuringiensis var. san diego (MYX 1806), and B. thuringiensis var. tenebrionis (Trident) and neem (Margosan-O). Insecticidal sprays were applied using a tractor-mounted boom sprayer, with a single hollow cone nozzle over each row. Sprays were applied in 654 liters of water per ha (70 gal/acre) at 827 kPA (120 psi). Data were collected from the center 2 rows. Larvae were counted on 20 plants per plot. Data were expressed as mean number of larvae or plant injury (percent defoliation) × number of days elapsed, i.e., Area Under the Curve (AUC). AUC for CPB was computed separately for the first and second generation then summed. Two-way analysis of variance was used to test for treatment differences.

Colorado Potato Beetle Control with Traditional Insecticides, 1991

Abstract Superior' potatoes were planted 1 Mar, near Nixonton, NC, on 42 inch centers. Thimet 15 G (3.0 lb [AI]/acre) was applied in furrow at planting. Plots consisted of single rows, 10 ft long, replicated 4 times in a randomized complete block design. Alleys of 5 ft were used between replicates. Treatments were applied with a CO2 pressurized backpack sprayer with a single hollow cone nozzle (18 × ) . Application rate was 80 gal/acre delivered at 50 psi. Applications were made 2 May (all materials) and 9 May (2 rates of Trigard and Thiodan). Counts of insects on 3 hills/plot and visual damage ratings were made 9 and 14 May. Small larvae were assumed to be first and second instars, and large, third and fourth. Potatoes were harvested and yields recorded 10 Jun.

Colorado Potato Beetle Control with Foliar Sprays, 1991

Abstract Experimental plots were established in a potato field on the UI Research and Extension Center, Caldwell, ID. The soil type was Portneuf silt loam and irrigation was by furrow. Thirteen treatments and two untreated check plots were replicated four times in a randomized complete block design. Individual treatment plots were 4 rows (36 inch row spacing) wide by 25 ft long. Applications were made as a broadcast spray using a CO2 pressurized backpack sprayer. Twenty gal of finished spray were applied [using 30 psi and X-8 (Spraying Systems) hollow cone nozzles] to all plots except for Kryocide which was sprayed using 50 gal/acre. Pre-treatment counts were made and the first insecticide treatments were applied 25 Jun. A second application of MYX 1806, Foil, Kryocide and ground root of Chinese Bittersweet (CB) was made on 2 Jul. All beetle stages were counted and percent defoliation observations were made weekly using whole plant inspections of the center five hills of the center two plot rows. Larval stages were separated into small (1-3 instar) and large (4-5 instar). Data were analyzed using ANOVA and Newman-Keuls studentized range test

Colorado Potato Beetle Control on Potatoes with NTN-33893, 1991

Abstract 'Superior' potatoes were planted in 20 foot rows on 15 and 17 Apr, '91. Both planting dates had identical treatments. Plots consisted of single treatment rows. The distance between rows was 36 inches and the distance between plants within the row was 9 inches. Plots were arranged in a randomized complete block design with 4 replications. The soil was a Norfolk “A” loamy sand. Granular treatments were applied with a small shaker can over the top of seed pieces in the furrow. In furrow spray treatments were applied to the seed pieces at the rate of 20/gal per acre with a one pint bottle with a trigger pump. All treatments were applied at planting. In evaluating the teatments, direct counts of the number of Colorado potato beetle adults, larvae and egg masses/5 stems and defoliation were recorded. Defoliation categories were assigned using a pretransformed defoliation rating scale, based on dividing 90° into 13 steps corresponding to arcsin transformation values (Little & Hills 1978). Dry conditions prevailed for much of the growing season.

Insecticides for Colorado Potato Beetle Control on Potatoes, 1991

Abstract Potatoes were planted in 2 fields on 10 Apr at the Eastern Shore Agricultural Experiment Station, Painter, VA. Each plot consisted of a 25 ft long row bordered on each side by an untreated guard row. Potatoes were planted with 10-inch plant and 36-inch row spacing. Treatments were replicated 4 times in a randomized complete block design. Sprays were applied with a propane compressed gas backpack sprayer using 3 hollow cone nozzles per row and delivering 70 gal water/acre at 40 psi. Sprays were applied 13, 20, 28 May, and 4 Jun unless otherwise noted in the tables. Evaluation criteria consisted of counts of CPB small (1st and 2nd instar) larvae, large (3rd and 4th instar) larvae, and adults on 10 randomly chosen stems per plot. Percent defoliation was rated on 6 and 14 Jun in field 1 and 6 and 13 Jun in field 2. Potatoes were harvested on 10 Jul in both fields and weighed to determine Grade A and total tuber yields.

Evaluation of Various Spray Nozzle and Volume Combinations for Control of Colorado Potato Beetle (Coleoptera: Chrysomelidae) with Synthetic and Biological Insecticides

Field experiments were done in potatoes, Solanum tuberosum L., to evaluate various spray nozzle and volume combinations for control of Colorado potato beetle, Leptinotarsa Decemlineata (Say), with synthetic insecticides and Bacillus thuringiensis . Colorado potato beetles were moderately tolerant to permethrin, and use of hollow-cone nozzles resulted in improved control compared with flat-fan nozzles. When flat-fan nozzles were used with permethrin, increasing spray volume from 103 to 298 Iiter/ha resulted in a reduction in defoliation and an increase in tuber yield. Colorado potato beetles were highly susceptible to esfenvalerate. Nozzle type and spray volume had no significant effect on insect density or defoliation. However, a significant linear relationship existed between Colorado potato beetle counts and esfenvalerate spray volume. On some sample dates, density of Colorado potato beetles was reduced in the high volume (467 liter fha) esfenvalerate treatment compared with the low volume (93 liter fha) treatment. Efficacy of cryolite for control of Colorado potato beetle was not significantly influenced by nozzle type or spray volume treatment. In experiments with B. thuringiensis var. san diego (M-One Insecticide), use of three hollowcone drop nozzles per row resulted in significantly lower Colorado potato beetle density and defoliation, compared with use of hollow-cone nozzles arranged over the tops of the plants. Colorado potato beetle control with B. thuringiensis was enhanced (with both nozzle treatments) by increasing spray volume from 140 to 560 liter fha.

Feeding Responses of Adult Coleomegilla maculata (Coleoptera: Coccinellidae) to Eggs of Colorado Potato Beetle (Coleoptera: Chrysomelidae) and Green Peach Aphids (Homoptera: Aphididae)

Feeding responses that influence the effectiveness of a polyphagous endemic coccinellid, Coleomegilla maculata (DeGeer), for biological control of Colorado potato beetle, Leptinotarsa decemlineata (Say), in potato were examined in the laboratory. Consumption rate, functional response, prey preference, and the effect of alternate prey were studied for C. maculata adult females feeding upon eggs of Colorado potato beetle; Myzus persicae (Sulzer) and corn pollen were alternate food sources. C. maculata females continuously supplied with eggs attacked an average of 20.8 eggs per 48 h, and introduction of M. persicae significantly reduced but did not eliminate egg feeding. Females starved for 24 h showed a Type II functional response to egg density when offered 10–70 eggs per 24 h in small cages at 26 ± 2°C. Data fit well to the Holling disk equation, which predicted maximum egg consumption of 31.5 eggs per 24 h. The functional response curve showed suppression of egg feeding at high egg densities when aphids were present as alternate prey, but no effect was evident at low egg densities. There was no change in functional response with corn pollen as the alternate food. When Colorado potato beetle eggs and aphids were available in equal numbers, females did not prefer either prey at low prey densities, but they preferred aphids over eggs at high densities. Eggs were an adequate (but not optimal) diet for larval development and adult oviposition relative to M. persicae or corn pollen. Some implications for ecology and effectiveness of C. maculata for control of Colorado potato beetle in potato are discussed.

An integrated pest management approach to Colorado potato beetle control in the USA1

An integrated pest management program utilizing the egg parasite Edovum puttleri for Colorado potato beetle control was developed at Beltsville (US). This program presents an alternative control that is environmentally safe, cost‐effective and energy‐efficient.

Control of Colorado Potato Beetle on Potatoes, 1988

Abstract The insecticide trials were conducted in Lancaster County, Landisville, Pa. Certified 'Katahdin' seed potatoes were planted on 3 May with 9 inch spacing between plants and 3 ft between rows. Plot size was 4 rows by 25 ft with 2 border rows arranged in a randomized complete block design with 4 replicates. Temik 15 G (1.0 lb [AI]/acre) was applied in furrow at planting for all treatments. The control received Temik at planting, however, no specific foliar insecticide was applied to the plot. The entire field was sprayed with 0.1 lb [AI]/acre permethrin on 8 and 15 Jun to protect the emerging plants from adult Colorado potato beetle (CPB). An application of Asana 0.0375 lb Al/acre was applied on 5 Jul to reduce the high density of CPB. Experimental treatments were applied on 30 Jun, 5, 22, 25 Jul, and 4 Aug. The entire field was sprayed again with Asana (0.0375 lb Al/acre) on 9 Aug. Border rows were sprayed with Pydrin (0.2 lb Al/acre) and piperonyl butoxide (PBO) (0.4 lb Al/acre). A George White boom sprayed delivering 30 gal/acre at 27 psi was used to spray the plants. A hand held COa pressurized spray was also used to apply the materials. Thirty gal of spray material was delivered/acre at 27 psi also with the hand sprayer. Sprays were applied by the tractor mounted sprayed at 3 mph; a Ty-18 type nozzle with 50 mesh screens were used. Five or 10 stems/plot were sampled before the spray was applied. Counts were taken 24-72 h following application with all stages of CPB being sampled. Average daily temperatures (°F) were 62.6° for May, 70.6° for Jun, 77.7° for Jul, and 75.2° for Aug. Departure from average was 8.8 degrees for this period. Rainfall totals were 5.99 inches in May, 1.16 inches in Jun, 7.97 inches in Jul, and 4.37 inches in Aug.

Foliar Sprays for Control of Colorado Potato Beetle on Potato in the Red River Valley of Minnesota and North Dakota, 1990

Abstract Certified B-size potatoes were planted 16 May at the University of Minnesota Northwest Experimental Station, Crookston. Plots at Grafton, North Dakota were in a commercial production field. Experimental plots were 25 ft long with 40-inch row spacing. Treatments were arranged in a completely randomized design with 4 replications. Insecticidal sprays were applied 3 Jul, with a CO2-powered handsprayer delivering 100 gal of water/ acre. CPB populations were moderately high. Posttreatment counts were done 48 h after spraying. Evaluations consisted of direct counts of total CPB larvae on 20 whole plants.

Irish Potato, Control of Colorado Potato Beetle, 1990

Abstract The experiments were randomized complete block designs with 6 replicates, except experiment CPB-A which had 4 replicates. Experiment CPB-A was planted 17 May; experiments CPB-B, CPB-C, and CPB-D were planted 29 May; and experiment CPB-E was planted 31 May at Presque Isle, Maine, on land that was in clover in 1989. The 3.0 m space between blocks and the 1.8 m space between the four-row plots was bare soil. All rows were planted with an assisted-feed planter 0.9 m apart and 15.0 m long and the healthy whole Katahdin seed (ca 75 g) were 30 cm apart. Fertilization and cultivation practices were normal for the area. Late blight was controlled by 5 foliar applications of Manex 4 L (2338 ml/ha on 27 Jul; 2806 ml/ha on 3, 9, 16, and 23 Aug). Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles/row at 6.3 kg/cm2 pressure and 0.94 kl/ha. Numbers of larvae and adults were counted on 25 whole plants in the middle rows of each plot. When dates of count and application were the same, beetle counts were made prior to application of insecticides. Analyses of variance were calculated following transformations of data using log10(x + 1), except experiment CPB-A where no transformations were done. Means of all larval stages and adult beetles were compared using DMRT. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun, Jul, and Aug was respectively 7.3, 10.2, and 14.8 cm. The average temperature for each of the same 3 mo was 17.6, 19.5 and 19.7 deg C.

Control of Colorado Potato Beetle with Natural Product Insecticides, Grand Forks, 1990

Abstract Natural product insecticides used in this experiment were Bacillus thuringiensis var. san diego (MYX 1806), B. thuringiensis var. tenebrionis (Trident and BK-102) and azadirachtin (Margosan-O) from the neem tree, Azadirachta indica. Plots were planted 15 May at the Research Farm, Red River Valley Potato Growers Association, Grand Forks, N.D. Plots were 6 rows wide, 16.8 (55 ft) long, with 91 cm (36 inches) spacing between rows and 30 cm (12 inches) between plants. The two center rows of each plot were planted with certified 'Red Pontiac' seed pieces, the remaining four rows were planted with certified, B-size, 'Russet Burbank.' Plots were separated on all sides by 1.8 m (6 ft) of cultivated soil. A completely randomized plot design with 4 replications was used. Plots were scouted daily from CPB egg masses beginning 21 Jun. When egg masses were found these were flagged and checked daily for hatch. Timing of first spray application was based on egg hatch. Three basic spray schedules were used: first application at 30% hatch of flagged egg masses and subsequent application on either a 7 d or 10 d schedule, or first application at 30% hatch of all eggs (unflagged) laid on or before that sampling date and subsequent applications on a 7 d schedule. Plots were sprayed 1-3 times for each generation of CPB larvae: 29 Jun (30% hatch of flagged eggs—1st generation) 2 Jul (30% total hatch—1st generation), 5,9, 12, 16, 19 and 31 Jul (30% hatch of flagged eggs—2nd generation), 6 Aug (30% total hatch—2nd generation), 10, 13 and 14 Aug. Insecticidal sprays were applied using a tractor-mounted boom sprayer, with a single Teejet nozzle over each row. Sprays were applied in 150 liters water/ha (40 gal/ acre) at 275 kPa (40 psi). All data were collected from the two center rows of each plot. CPB larvae (small = 1st and 2nd instar, large = 3rd and 4th instar) were counted on 20 randomly selected whole plants per plot, PLH nymphs were counted on 35 mid-plant leaves per plot. Leaf loss to defoliation (by CPB) and hopperbum (injury caused by PLH) were estimated visually (by 2 individuals per sampling date) as percent foliage lost. CPB were counted on 4, 10 and 17 Jul, and 1, 8 and 17 Aug; defoliation was estimated on 10, 17 and 24 Jul, 1, 8 and 15 Aug; PLH were counted on 4, 10, 17 and 24 Jul, 1, 8 and 17 Aug; hopperbum was estimated on 1, 8 and 15 Aug. Insect data and plant injury ratings were expressed as mean insect numbers or plant injury × number of days elapsed (= Area under Curve). AUC for CPB was calculated separately for 1st and 2nd generations, and then summed. Yields were obtained 2 Oct by harvesting one center row from each plot. Two way analysis of variance was used to test for treatment differences in pest densities, plant injury and yield. The 1990 growing season at Grand Forks was characterized by severe drought from late Jun through harvest.

Control of Colorado Potato Beetle with Natural Product Insecticides, Rosemount, 1990

Abstract Natural product insecticides used in this experiment were Bacillus thuringiensis var. san diego (MYX 1806), and B. thuringiensis var. tenebrionis (Trident and BK-102) and azadirachtin (Margosan-O RH 0000 and RH 9999) from the neem tree, Azadirachta indica. Certified B-size seed potatoes were planted 23 May at the Plant Pathology Farm, Rosemount Agricultural Experiment Station, University of Minnesota. Plots were 6 rows wide, 19.8 m (65 ft) long, with 102 cm (40 in) spacing between rows and 30 cm (12 in) between plants. Plots were separated on all sides by 2 m (6.7 ft) of cultivated soil. A completely randomized plot design with 4 replications was used. Plots were scouted daily for CPB egg masses beginning 15 Jun. When egg masses were found these were flagged and checked daily for hatch. Timing of first spray application was based on egg hatch. Three basic spray schedules were used: first application on 30% hatch of flagged egg masses and subsequent applications on either a 7 d or 10 d schedule, or first application on 30% hatch of all eggs (unflagged) laid on or before that sampling date and subsequent applications on a 7 d schedule. Plots were sprayed 1-4 times for each generation of CPB larvae. Spray dates were: 21 Jun (30% hatch of flagged eggs—1st generation), 25 Jun (30% total hatch—1st generation), 29 Jun, 1, 2, 5, 9, 20 Jul (30% hatch of flagged eggs—2nd generation), 25 Jul (30% total hatch—2nd generation), 27 Jul, 30 Jul, 1,3, 8, 9, 10 and 15 Aug. Insecticidal sprays were applied using a tractor-drawn boom sprayer with drop nozzles, 3 hollow-cone drop nozzles to the row. Sprays were applied in 795 liters water/ha (85 gal/acre) at 620 kPa (90 psi). All data was collected from the center 4 rows of each plot. CPB larvae (small = 1st and 2nd instar, large = 3rd and 4th instar) were counted on 20 randomly selected whole plants/plot. On one sampling date, 6 Jul, CPB counts were based on only 10 plants/plot and not recorded by size-class. PLH nymphs and green peach aphid apterae were counted on 35 mid-plant leaves/plot. Leaf loss to defoliation (by CPB) was estimated visually (by 2-5 individuals per sampling date) as percent foliage lost. Hopperburn (the injury caused by PLH) was estimated visually (by 2-5 individuals/sampling date) on a 0-6 scale, 0 = no injury. CPB were counted on 26 Jun, 6, 31 Jul, 8, 15, 20 and 28 Aug. PLH were counted 3, 10, 16, 24 and 31 Jul, 6, 13, 21 and 29 Aug. GPA were counted 3 Jul, 6, 13, 21 and 29 Aug. Defoliation was estimated 29 Jun, 2, 5, 10 and 16 Jul, 2, 7, 10, 16, 23 and 30 Aug. Hopperburn was estimated on 10, 16, 23 and 30 Aug. Data was expressed as mean insect numbers or plant injury × number of days elapsed (= Area Under Curve). AUC for CPB was calculated separately for 1st and 2nd generations, and then combined. For calculation of AUC for 1st generation CPB the 6 Jul counts were multiplied × 2 and included in the column CPB large. Two way analysis of variance was used to test for treatment differences in pest densities, plant injury and yield. Yields were obtained 17 Sep by harvesting one center row from each plot.

Control of Colorado Potato Beetle on Potato, 1987

Abstract The trials were conducted in Lancaster County, Landisville, Pa. Certified class B 'Katahdin' seed potatoes were planted on 30 May with 9 inch spacing between plants and 34 inches between rows. Plot were 4 rows by 25 ft with 2 border rows arranged in a randomized complete block design with 4 replicates. Temik 15 G (1.0 lb [AI]/acre) was applied in furrow at planting for all treatments. The control received Temik at planting, however, no foliar treatment was applied to the plot. The foliar insecticides were applied on 24 Jun, 16, 30 Jul, and 11 Aug with a George White boom sprayer delivering 30 gal/acre at 27 psi. Border rows were sprayed with Asana (0.0735 lb [AI]/acre) on 26 Jun by hand, and with the boom sprayer on later dates. A Tx-18 type spray nozzle with a 50 mesh screen was used, with the tractor speed at 3 mph. Ten stems per plot were sampled immediately before and 24 h after spraying, with all stages of Colorado potato beetle being sampled. A subjective damage index was implemented beginning on 2 Jul: 1 indicating 0-5% leaf loss to 5 indicating >75% defoliation. Two 25 ft rows/plot were harvested on 25 Sep, and graded by size 2 weeks later. Average maximum and minimum daily temperatures (degree fahrenheit) were 76.2° and 49.3° for May, 89.6° and 59.1° for Jun, 89.0° and 63.5° for Jul, and 85.5° and 58.5° for Aug, respectively. Rainfall totals were 3.62 inches in May, 1.88 inches in Jun, 2.85 inches in Jul, and 1.99 inches in Aug. Precipitation for May was 0.04 inches above normal. Jun precipitation was 2.22 inches below normal. Jul precipitation was 1.52 inches below normal. Aug precipitation was 1.62 inches below normal. A factor affecting the trials was drought stress (precipitation for May through Aug was 5.32 inches below normal).

Colorado Potato Beetle Control on Potatoes, 1990

Abstract Potatoes were planted on 17 Apr at the Eastern Shore Agricultural Experiment Station, Painter, Va. Each plot consisted of a single 25 ft row bordered on each side by an untreated row. Potatoes were planted with 10 inch plant and 36 inch row spacing. Treatments were replicated 4 times in a randomized complete block design. Sprays were applied with a propane compressed gas backpack sprayer using 3 hollow cone nozzles per row and delivering 70 gal water/acre at 40 psi. Applications were made weekly beginning 11 May through 25 Jun. Ambush 2 EC [0.10 lb (AI) acre] was applied on treatments 1-6 and 19-23 on 11 May to control CPB adults.

Colorado Potato Beetle Control with Biological and Synthetic Insecticides, Pasquotank County, 1989

Abstract Su perior' potatoes were planted near Weeksville, N.C. Single row plots, 6 . 1 B long with rows 1.06 m apart were replicated 4 times in a randomized complete block design. Treatments were applied using a COa pressurized sprayer with a single hollow cone nozzle (18 X) operating at 60 psi to apply 119.2 liter/ha. Treatments were applied 16 May (all) and 24 May (M-One, Trident and Trident II). Visual estimates of foliar damage and/or insect counts were made 23 May and 1 Jun. Larvae were counted on 3 hills/plot. Small larvae were assumed to be 1st and 2nd instars, and large 3rd and 4th.

Colorado Potato Beetle Control with Foliar Sprays, 1990

Abstract Experimental plots were established in a potato field on the UI Research and Extension Center, Caldwell, Idaho. The soil type was Portneuf silt loam and irrigation was by furrow. Twelve treatments and an untreated check were replicated 4 times in a randomized complete block design. Individual treatment plots were 4 rows (36 inch row spacing) wide by 25 ft long. Applications were made as a broadcast spray using a CO2 pressurized backpack sprayer. Twenty gal of finished spray were applied (using 30 psi and X-8 [Spraying Systems] hollow cone nozzles) to all but the Kryocide plots. Kryocide was applied using 50 gal/A. Pretreatment counts were made and the first insecticide treatments were applied 20 Jun. A second spray was applied to all but the Asana plots on 27 Jun. All stages of beetles were counted using whole plant inspections of the center ten hills of the center two plot rows. Larval stages were separated into small (1-2 instar). Data were analyzed using ANOVA and Newman-Keuls studentized range test.

Evaluation of a Biological and a Botanical Insecticide for Colorado Potato Beetle Control, Rosemount, 1990

Abstract Natural product insecticides used in this experiment were B. thuringiensis var. tenebrionis (BK-102) and azadirachtin (RH 0000 and RH 9999) from the neem tree, Azadirachta indica. Es-fenvalerate (Asana XL) was used as a conventional insecticide. Certified B-size seed potatoes were planted 23 May at the Plant Pathology Farm, Rosemount Agricultural Experiment Station, University of Minnesota. Plots were 1 row wide, 7.6 m (25 ft) long, with 102 cm (40 in) spacing between rows and 30 cm (12 in) between plants. A completely randomized plot design with 4 replications was used. Potatoes were scouted daily for CPB egg masses beginning 18 Jul. When egg masses were found these were flagged and checked daily for hatch. Timing of first spray application was based on egg hatch. Two basic spray schedules were used: first application at 30% hatch of flagged egg masses and subsequent applications on a 7 d schedule, or first application at 30% hatch of all eggs (unflagged) laid on or before that sampling date and subsequent applications on a 7 d schedule. Plots were sprayed 1-4 times for second generation of CPB larvae. Spray dates were: 20 Jul (30% hatch of flagged eggs—2nd generation), 25 Jul (30% total hatch—2nd generation), 27 Jul, 1, 3, 8, 10 and 15 Aug. Insecticidal sprays were applied in 935 liters water/ha with a CO2-powered handsprayer. CPB larvae were counted on 20 whole plants per plot on 1, 8, 15, and 22 Aug. Two way analysis of variance was used to test for differences in CPB densities.