Potato leafhopper: Empoasca fabae (Harris) Different insecticide treatments were assessed for control of the potato leaf hopper at one location (Saline Co., Kansas) in 2005 and two locations (Dickinson Co. and Republic Co., Kansas) in 2006.At each location, plots were arranged as a RCB design with 13 treatments, replicated four times in a field of alfalfa.Insecticide treatments were applied on 15 Jul, 2005 (Saline Co.), 07 Jul, 2006 (Dickinson Co.), and 06 Jul, 2006 (Republic Co.) to a plot size of 15 ft x 20 ft using a Solo back pack sprayer delivering 20 gpa at 30 psi.Ten sweeps (15 inch diameter) per plot were taken immediately prior to spraying (pre-treatment count), and at 4, 7, 14, and 28 days after treatment (DAT) application.Samples were immediately bagged, returned to the laboratory and counted on same day they were collected.Data were analyzed using analysis of variance (ANOVA) and means were compared with the LSMEANS procedure (P = 0.05) of PROC GLM.Differences were not detected among pre-treatment counts at all locations.In 2005, all treatments provided an unprecedented control of potato leafhopper on 4, 14, and 28 DAT.Similarly, all insecticide treatments had significantly reduced numbers of potato leaf hopper than the untreated check on all sampling dates at both locations in year 2006.At 28 DAT, population of potato leafhopper at both locations started to decline in all treatments, however, all insecticide plots had significantly less potato leafhopper than the untreated control.

Sunflower head moth: Homoeosoma electellum (Hulst

GRAIN YIELD FOR BT AND NON-BT CORN HYBRIDS, 1999:This trial was conducted to evaluate the corn borer resistance and grain yield of common Bt and non-Bt field corn hybrids in southwest Kansas.Corn hybrid plots were machine planted on 28 Apr at 34,400 seeds/acre at the Southwest Research-Extension Center near Garden City, KS.Spot replanting was done as necessary.The plots were four rows wide (10 ft) with two additional rows (5 ft) of Bt corn planted between the plots as border rows.The plots were 30 ft long with 10 ft alleyways between sets of plots.The border rows and alleyways were included to reduce larval migration between plots.The experimental design was a randomized block design with four replications.The 14 hybrid entries included 8 Bt hybrids and 6 non-Bt hybrids.When the plants were at the pre-tassel stage, a hailstorm on 1 Jul caused 50 to 60% defoliation and bruised and broke many stalks.Data for second-generation corn borers were taken from 10 plants in the two center rows of each plot (5 consecutive plants in each row).The plants were dissected to measure corn borer tunneling and record the number and species of corn borer.Kernel damage (mostly corn earworm) was recorded as the estimated percentage of kernels damaged on each ear.The lodged corn was harvested by hand and the standing corn was machine harvested.Grain yield was calculated for standing and total grain yield per acre at 15.5% moisture.Mean separation was preformed using LSD (P=0.05).

GRAIN YIELD FOR BT AND NON-BT CORN HYBRIDS, 1998: Corn hybrid plots were machine planted on 8 May at 26,000 seeds/acre at the Sandyland Experiment Field near St. John, KS.Spot replanting was done as necessary.The plots were 4 rows wide (10 ft) with two additional rows (5 ft) of Bt corn between the plots as border rows.The plots were 30 ft long with alleyways 10 feet long.The border rows and alleyways were included to reduce larval migration between plots.The experimental design was a split-plot with three replications.The main plots were insecticide protected versus insecticide unprotected, and the sub-plots were the corn hybrids.The protected blocks were sprayed 22 Jul with bifenthrin at 0.08 lb (AI)/acre.The 26 entries included 15 Bt hybrids and 11 non-Bt hybrids.All corn borer evaluations were the result of natural infestations.First generation shot-hole damage was evaluated on 22 Jul using the Guthrie scale.Data for second generation corn borers were taken from 5 plants chosen at random from the two center rows of each plot.The plants were dissected to record corn borer numbers and measure corn borer tunneling.Kernel damage (mostly corn earworm) was recorded as the number of kernels damaged on the whole ear.Yield was determined by hand harvesting the two middle rows of each plot in late Oct. Ears from standing plants and those from fallen plants were harvested separately.Grain yield was calculated for standing and fallen grain based on bu/acre at 15.5% moisture.The data for sprayed and unsprayed blocks were analyzed separately as two single-factor experiments.Mean separation was preformed using LSD (P = 0.05).First generation corn borer leaf feeding damage was light and averaged 1.3 for the non-Bt hybrids and 1.04 for the Bt hybrids on the Guthrie scale (individual hybrid data not shown).Second generation European and southwestern corn borer pressure averaged 0.13 and 0.98 larvae per plant, respectively, in the unsprayed non-Bt plots.In hybrids with Bt11, MON810, CBH351, and 176 and the insecticide treatment, second generation ECB larvae were reduced by 100, 92, 100, 0 and 69 percent, respectively; second generation SWCB larvae were reduced by 100, 100, 100, 66 and 95 percent; corn borer tunneling was reduced by 100, 99, 100, 58 and 89 percent.Corn earworm damage to kernels in the ear tip was moderate, averaging 23.3 kernels damaged per ear in the unsprayed non-Bt.Hybrids with Bt11, Mon810, CBH351 and sprayed non-Bt hybrids averaged 76, 30, 42 and 45 percent reduction in kernel damage, respectively.Hybrids with Bt176 had little reduction in kernel damage.Yield losses from lodged plants was reduced by 100, 99, 97, 35 and 96 percent.The yield losses to girdling by southwestern corn borers averaged 16.6 bu/acre for the unsprayed non-Bt hybrids 0.7 bu/acre for sprayed non-Bt hybrids and 10.9 bu/acre for hybrids with event 176.Hybrids with Bt11, MON810 and CBH351 had virtually no yield loss. Across the Bt hybrids with events Bt11, MON810 and CBH351 there was a yield difference between sprayed and unsprayed of 8.1 bu/acre.This yield difference was possibly due to differences in spider mite populations, since bifenthrin is known to have miticidial activities.Grain yield averaged 127.4 bu/acre across all hybrids in the sprayed block, and 116.8 bu/acre in the unsprayed block.The standard hybrid, Pioneer 3162IR, yielded only 96.0 bu/acre in the sprayed blocks, and 89.5 bu/acre in the unsprayed blocks.This yield was uncharacteristically low for this hybrid.Although gray leaf spot is sometimes a problem for this hybrid, we had no observations of unusual levels of disease infection in this trial.

Gaucho' (imidacloprid; 1-[(6-chloro-3-pyridinyl)methyl]-N-nitro-2-imidazolidinimine) is a seed treatment insecticide widely used on sorghum [Sorghum bicolor (L.) Moench] to control a number of pests, including greenbugs [Schizaphis graminum (Rondani)], chinch bugs [Blissus leucopterus leucopterus (Say)], and wireworms (Limonius sp.). A series of tests was conducted at five locations in Kansas during 1996 and 1997 and three locations during 1998 to determine whether a yield response results even in the absence of pests when Gaucho is used as a seed treatment on grain sorghum. Results varied. Gaucho improved yields at Hesston, especially in the June plantings but some hybrids benefited more than others. These differences may have been due to chinch bugs that were observed in the plots and were known to be troublesome in the area. Because their numbers were low, other factors may have played a role. At the other locations and in the absence of chinch bugs, Gaucho had less of an influence on yields. At Garden City, where some greenbugs developed, Gaucho provided early-season control, but infestations were too light to influence yields. At Hays, Gaucho treatments appeared to have some influence on the numbers of corn earworms [Helicoverpa tea (Boddie)] in sorghum heads in one planting, although yield differences were not significant. Overall, this study found no consistent yield increases in fields treated with Gaucho in the absence of observable pest activity.

GRAIN YIELD FOR BT AND NON-BT CORN HYBRIDS, 1997B: Corn hybrid plots were machine planted on 7 May at 26,000 seeds/acre at the Sandyland Experiment Field near St. John, KS.Spot replanting was done as necessary and due to an error some plots could contain a few off-type plants (average of 3-5).Most of these plants were excluded during the corn borer evaluations by avoiding unusually small plants, but they were included in the yield calculations.The plots were four rows wide (10 ft) with two additional rows (5 ft) of Bt corn planted between the plots as border rows.The plots were 30 ft long with alleyways 10 ft long.The border rows and alleyways were included to reduce larval migration between plots.The experimental design was a split-plot with four replications; however, one replication was abandoned for late season observations due to lack of efficacy of the insecticide treatment in that rep.The main plots were insecticide protected versus insecticide unprotected, and the sub-plots were the 15 corn hybrids.The protected blocks were sprayed 4 Aug with bifenthrin at 0.08 lb (AI)/acre.The 15 hybrid entries included 6 Bt-and 9 non-Bt-hybrids.Pioneer 3299 was a check with reported natural corn borer resistance.First generation shot-hole damage was light so the hybrids were evaluated by counting plants showing noticeable damage in each plot.Data for second generation corn borers were taken from 5 consecutive plants in one of the two center rows of each plot.The plants were dissected to measure corn borer tunneling and record the number and species of corn borer.Kernel damage (mostly corn earworm) was recorded as the percentage of kernels damaged on each ear.Stalk rot rating was recorded as the number of internodes at the base affected by stalk rot.Yield was determined by hand harvesting the two middle rows of each plot in late Oct. Ears from standing plants and those from fallen plants were harvested separately.Grain yield was calculated for fallen and total grain yield per acre at 15.5% moisture.The data for sprayed and unsprayed blocks were analyzed separately as two single-factor experiments.Mean separation was preformed using DMRT (P = 0.05).Second generation southwestern corn borer pressure was heavy and averaged to 0.7 larva/plant on the unsprayed non-Bt hybrids.Second generation European corn borer pressure was moderate and averaged 1.0 larva/plant on the unsprayed non-Bt hybrids.Control of second generation European corn borer larvae averaged 100, 94, 72 and 58%; control of southwestern corn borer larvae averaged 100, 96, 18 and 62%; control of corn borer tunneling averaged 100, 93, 53 and 67%; control of kernel damage averaged 76, 61, 0 and 5% and reduction in fallen corn averaged 95, 81, 31, and 58% for the three Bt events MON810 and Bt 176, unsprayed) and the insecticide treatment (9 sprayed non-Bt hybrids), respectively, when compared with the average of the 9 unsprayed non-Bt hybrids.Total grain averaged 205.6, 209.1, 187.7, 176.0 and 189.5 bu/acre for the three Bt events (unsprayed) and the unsprayed and sprayed non-Bt hybrids, respectively.

Greenbugs collected from Kansas, Texas, Nebraska, Colorado, and Oklahoma were tested to determine the occurrence of greenbug, Schizaphis graminum (Rondani), biotypes E and I in sorghum and wheat from 1991 through 1993. The occurrence of biotype I appears to be widespread in the Texas panhandle and in Kansas. Biotype I appears to occur more frequently in southwestern Kansas than other areas of Kansas. An intensive field survey was conducted in 1992 and 1993 to determine occurrence of the two greenbug biotypes within 10 randomly selected sorghum fields in southwestern Kansas. Biotype I occurred in ail but one intensively sampled field.

SUMMARY We tested the systemic insecticide fipronil applied as a foliar spray or as a seed treatment for effectiveness at suppressing Dectes stem borer (Dectes texanus) in commercial soybean varie ties. Both foliar and seed treatments significantly reduced Dectes damage on soybean. There were slight differences in levels of infestation for the four tested varieties, but foliar treatment was effective in each variety. The three doses of fipronil seed treatment significantly reduced Dectes infestations. There was a small increase in effectiveness of the highest dose of fipronil over the lowest dose, but this difference was not statistically significant. Treated plots yielded 1.4 to 7.3 bu/a more than untreated plots, but this difference was not statistically significant. PROCEDURES

Data from Bt corn trials at Garden City and St. John, KS were analyzed to compare the potential economic returns of various Bt corn refuge-planting strategies. The results of this analysis indicate that the costs of the refuge-planting strategies are relatively small in comparison with the increased returns associated with Bt corn. strategies; unsprayed non-Bt corn, insecticide-sprayed non-Bt corn, unsprayed Bt corn, and insecticide- sprayed Bt corn. The insecticide treatment used in the trials was Capture at 0.08 lb ai/A applied for corn borer control. Capture at this rate also would reduce spider mites and corn rootworm adults if present. These hybrids were used in all four studies. The events MON810 or Bt11 (sold under the Trademark YieldGard) were chosen for this comparison because they provide very good control of southwestern corn borer and are available in corn hybrids that are well- adapted for this area. In these trials, both standing yield and fallen yields were recorded. The corn in these trials was harvested in October, so there was a reasonable chance of lodging from corn borer damage. Standing yield was from plants that did not lodge from corn borer damage and represented the yield that could be expected, if fields were harvested late and lodging was extensive. Total yield was the sum of the standing yield plus the hand-harvested yield from any lodged plants or dropped ears. It represented the overall physiological yield including corn borer losses associated with early harvest.

SUMMARY This trial was conducted to evaluate the efficacy of corn hybrids containing events MON89034 (YGVTPRO), MON810 (YGCB) and TC1507 (HXCB) for controlling the corn earworm (CEW), Helicoverpa zea (Bobbie), and the southwestern corn borer (SWCB), Diatraea grandiosella Dyar. All three of the Bt hybrids gave excellent control of SWCB. Efficacy of the YGVTPRO event was outstanding against both SWCB and CEW. A significant proportion of kernel damage appeared to be attributable to the Dusky Sap Beetle (DSB), Carpophilus lugubris Murray, and none of the Bt corn hybrids had efficacy on this insect.

SUmmary t he Banks grass mite (BG m) populations increased from 26 to 240 mites per 2 plants by august 8 and then declined to �2 mites per 2 plants on august 23. the twospotted spider mite (tSm) populations increased rapidly in August, from 13 per 2 plants on August 8 to 628 per 2 plants on September 8. the percentage of the population that was TSM increased from 5% to 97% during the season. The two rates of the standard miticide, Capture® 2EC (bifenthrin active ingredient), gave some early control (up to 40%) of BGM. The combination of Capture® plus Dimethoate also seemed to give some early control of both mites. the two rates of Fanfare® (bifenthrin active ingredient) gave some early control of BGM (up to 65%). The two Onager® combinations gave reasonable BGM control, 38 to 85% from 7 to 21 days after treatment (DAT). The Onager® plus Capture® treatment seemed to have some impact (24 to 39%) on the TSM populations. The two formulations of Oberon® gave excellent BGM control, 53 to 89% out to 14 DAT, but the Oberon® 480EC treatment seemed to fade at 22 dat . these treatments seemed to have some impact on the twospotted spider mites, on the samples through 22 DAT (3 to 76%). Predator numbers were very small for most of the season, but predator mite populations increased late in the season, when spider mite populations were high. no differences in predator mite populations were observed among treatments. There were no significant differences in yields among the treatments, even though the coefficient of variance (CV) was only 8%. proCedUreS

SUMMARY

SUMMARY This study evaluated dispersal of European corn borer (ECB), Ostrinia nubilalis (Hübner), and the southwestern corn borer (SWCB), Diatraea grandiosella Dyar. In the year 2001, dye-marked ECB and SWCB pupae were placed near the center of a center-pivot-irrigated cornfield. The moths were allowed to disperse as they emerged and then recaptured with black light and pheromone traps. There were 21 black light traps and 39 pairs of ECB and SWCB pheromone traps installed in transects around the release point across the cornfield. Feral moths of both species were readily captured throughout the Bt cornfield and the 1 st flight was much lower than the 2 nd flight for both species. The 1 st flight peaked at 0.5 male and 0.38 female SWCB per trap and 8.6 male and 13.2 female ECB per trap. The 2 nd flight peaked at 78.3 male and 60.1 female SWCB per trap and 183.3 male and 348.0 female ECB per trap. A total of 2337 dye-marked SWCB moths dispersed from the release point. An average of 18% males and 4.3% females were recaptured beyond the release point. SWCB males and females were recaptured all the way out to the traps located 1200 ft from the release point and one male was recaptured outside the release field over the native grasses. A total of 4933, 5258, and 3751 male and 3312, 3962 and 2703 female dye-marked ECB moths dispersed from the release point in June, July and August releases, respectively. An average of 3.6, 2.7 and 10.1 % of the males and 0.3, 0.6 and 4.4 % of the females were recaptured beyond the release point in the three releases. ECB males and females were recaptured all the way out to the 1200 ft traps. Four ECB males were recaptured outside the release field in the neighboring cornfield. No dye-marked ECB moths were recaptured over the native grasses.