Plant Bugs In Cotton Research Articles

Termination of Insecticide Applications for Tarnished Plant Bug (Hemiptera: Miridae) Management in Cotton

Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is the most important insect pest of cotton, Gossypium hirsutum L., in the states of Arkansas, Louisiana, Mississippi, Tennessee, and Missouri. Foliar insecticide sprays are an important tactic within an integrated pest management (IPM) program for this pest which occurs from early flower bud development to cut out, a stage where the plant has reached the capacity for supporting fruiting positions and equivalent to when there are five nodes above the uppermost first position white flower (NAWF 5). Currently, NAWF and heat unit accumulation monitoring is limited, resulting in a need for a more simplified insecticide termination method that has the potential for wider adoption. Experiments were conducted in 2015 and 2016 in the previously mentioned states to determine when to terminate insecticide sprays for tarnished plant bug based on week of flowering. Treatments included terminating sprays after the second through sixth weeks of flowering, a season-long control, and an untreated control. In general, insecticides reduced densities of tarnished plant bugs in the sprayed treatments. When analyzed by location, treatments that resulted in cotton yields similar to the season-long control ranged from weeks two through five of flowering. These data suggest that treatments can be terminated after the fifth week of flowering. Data from this study indicate applications terminated after the fifth week of flowering would be similar to the current recommended termination timing of NAWF 5 plus 350 heat units. Results from this experiment will be used to better define a simplified IPM strategy for tarnished plant bug in cotton.

Evaluation of Selected Foliar Broadcast-Applied Insecticides for Management of Plant Bug in Cotton, 2017–2018

Evaluation of Selected Foliar Broadcast-Applied Insecticides for Management of Plant Bug in Cotton, 2017–2018

Efficacy of Insecticide Tank Mixes With Bifenthrin Against Tarnished Plant Bug in Cotton, 2018

Efficacy of Insecticide Tank Mixes With Bifenthrin Against Tarnished Plant Bug in Cotton, 2018

Evaluation of Insecticides Alone or as Reduced Rates in Tank-Mixtures for Control of Plant Bugs in Cotton, 2018

Evaluation of Insecticides Alone or as Reduced Rates in Tank-Mixtures for Control of Plant Bugs in Cotton, 2018

Evaluation of Insecticides Alone or in Tank-Mixtures for Control of Plant Bugs in Cotton, 2017

Evaluation of Insecticides Alone or in Tank-Mixtures for Control of Plant Bugs in Cotton, 2017

Evaluation of Selected Insecticides for Control of Plant Bugs in Cotton, 2017

Evaluation of Selected Insecticides for Control of Plant Bugs in Cotton, 2017

Susceptibility of Flowering Cotton to Damage and Yield Loss from Tarnished Plant Bug (Hemiptera: Miridae)

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is a major pest of cotton in the midsouthern United States, including the states of Arkansas, Mississippi, Louisiana, western Tennessee, and southeastern Missouri. Insecticides provide the primary form of control for this pest, and numerous applications are required annually to control the tarnished plant bug. Little information exists regarding when to terminate insecticide applications targeting tarnished plant bugs in cotton. Numerous sprays are made late in the season to protect a small percentage of the overall yield. Experiments were conducted at the Mississippi State University Delta Research and Extension Center to determine the impact of tarnished plant bug infestation timings on cotton yield. Two separate planting dates were utilized to determine the weeks of flowering that tarnished plant bugs can cause significant yield losses. There was a significant planting date by treatment interaction. Overall, yields were greater in the first planting date than the second planting date. In both planting dates, the first 4 wk of flowering were the most critical for tarnished plant bug control, and this is when the greatest yield losses occurred. Also, when no insecticide applications were made after the fourth week of flowering, no significant yield loss was observed. These data demonstrate the importance of scouting and adhering to treatment thresholds during the early flowering period. These data also suggest that thresholds may be able to be modified or eliminated after the fourth week of flowering, but more research is needed to confirm this.

Evaluation of Sequential Foliar Insecticides for Control of Plant Bugs in Cotton, 2014: Table 1

Selected insecticide treatments were evaluated for control of tarnished and clouded plant bugs in blooming cotton at the West Tennessee Research and Education Center (Jackson, TN). Cotton was planted on 5 May. The test was arranged in an RCB design with four replicates. Individual plots were 12.67 × 35 ft and planted at a rate of four seeds per row ft. Treatments were applied with a high-clearance sprayer calibrated to deliver 9.4 gpa at 40 psi with 8001 flat fan nozzles. The …

Evaluation of Strafer for Tarnished Plant Bug in Cotton, 2014: Table 1

An insecticide efficacy trial was conducted in cotton at the Macon Ridge Research Station near Winnsboro, LA, in 2014. Cotton was planted on 15 May 2014 on 40-in. rows. The test was an RCB design with four replications. Plots were four rows wide × 50 ft. in length. Insecticide treatments were applied using a John Deere 6000 series high clearance sprayer calibrated to deliver 12 GPA at 3.3 mph with Tee …

Temporal and Spatial Genetic Variability Among Tarnished Plant Bug (Hemiptera: Miridae) Populations in a Small Geographic Area

ABSTRACT The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important pest of cotton that also feeds on other crops and many wild hosts. In the mid-South, where tarnished plant bugs in cotton are controlled exclusively with synthetic insecticides, infestations resulted in >29% of all yield loss attributed to insect damage and the control costs exceeded US$10 per acre in 2013. They have developed resistance to the most commonly used insecticides. Estimations of gene flow and migration are important to understand the spread of resistance in tarnished plant bug populations. Here, we analyzed tarnished plant bugs collected from July to September, 2006, to estimate population genetic parameters using 13 microsatellite markers. Our data indicated that tarnished plant bug populations in the study area had undergone a population bottleneck and all loci deviated from Hardy—Weinberg equilibrium in one or more collections. Bayesian simulations and factorial correspondence analysis indicated the p...

Spatial and temporal distribution of heliothines and tarnished plant bugs across the landscape of an Arkansas farm

Abstract Farm records were used to study the temporal and spatial distribution of bollworm, Helicoverpa zea (Boddie), tobacco budworm, Heliothis virescens (F.), (collectively heliothines) and tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), on cotton, Gossypium hirsutum L., across a 4000 ha farm in southeastern Arkansas. The influence of the percentage of corn, Z. mays L., cotton, rice, Oryza sativa L., soybean, Glycine max L., and non-crop land within a 0.4 km buffer surrounding a cotton field and populations of heliothine eggs and tarnished plant bugs in cotton were examined over a three-year period. There was a positive relationship between the area in corn, Zea mays L., within 0.4 km of cotton fields and numbers of heliothine eggs in cotton in June 2004 and 2005. Positive relationships were observed between numbers of tarnished plant bugs in cotton and the surrounding area planted to corn, while negative relationships were observed for the area planted to cotton. Cotton fields with earlier dates of first flower had greater overall populations of tarnished plant bugs. Distributions of all three pests in cotton were at least partially explained by the time of year and the type of crop within the local environment. This indicates that more detailed spatial information and historical records may have value for managing cotton insects across large farms or communities.

Acephate Resistance in Populations of the Tarnished Plant Bug (Heteroptera: Miridae) From the Mississippi River Delta

A monitoring program that used a glass-vial bioassay to detect acephate resistance in populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae), was carried out with weed-collected populations from 20 sites in the delta of Arkansas, Louisiana, and Mississippi. Additional results from field tests using recommended rates of formulated acephate in cotton showed that plant bug populations with resistance ratio (RR50) values > 3.0 for acephate (from the glass-vial bioassay) would be difficult to control in the field. Over a 4-yr-period from 2001 through 2004, only one population tested with the glass-vial bioassay was found with an RR50 value > 3.0 for acephate, but six populations having RR50 values > 3.0 were found in the delta in 2005. In fall 2005, an additional 10 populations from the hill region (the cotton growing areas outside the delta) were tested and four of these populations had RR50 values > 3.0. The number of populations with RR50 values > 3.0 increased to five of 10 and 18 of 20 in the hills and delta, respectively, in fall 2006. Laboratory tests using resistant populations found that resistance to acephate was not sex-linked and the alleles controlling the resistance were semidominant in nature. Because of the large increase in resistant populations and the nature of the resistance found in this study, along with control problems experienced by growers in 2006, entomologists in the mid-South strongly recommended that alternation of insecticide classes in field treatments for plant bug control be used by growers in 2007. This control strategy probably helped control plant bugs in the hills of MS where plant bug pressure was low in 2007, and only one population was found in the fall with an RR50 value > 3.0. Plant bug pressure was very high in many parts of the delta in 2007, and 15 of the 20 populations tested in the fall had RR50 values > 3.0. In one field test in cotton, a population with multiple resistance was tested and not effectively controlled in treatments using recommended rates of carbamate, organophosphate, and pyrethroid insecticides. Alternation of insecticide classes may not work very well when populations are present that are resistant to three of the four main classes of cotton insecticides. New insecticides in different classes are badly needed for control of tarnished plant bugs in cotton in the mid-South.

Methods of analysis for georeferenced sample counts of tarnished plant bugs in cotton

The problem of analyzing georeferenced cotton pest insect samples when a large percentage of the counts are zero is examined. The use of appropriate statistical methods for their analysis is required. To demonstrate this, georeferenced samples (n = 63) of tarnished plant bugs (TPBs; Lygus lineolaris [Palisot de Beauvois] (Heteroptera: Miridae)) were analyzed by three statistical methods and the results were compared. Correlation analysis of the sample counts with 25 classes of cotton growth derived from an unsupervized classification of multispectral imagery was followed by a complete enumeration analysis comprising three scenarios. The first scenario assumed the insect samples were unstratified. A distribution of sample averages was created by complete enumeration of all combinations of samples taken four at a time. The second scenario used imagery of the cotton fields to allocate the samples among three cotton growth categories (marginal, good or best) derived by a supervized classification of the 25 unsupervized classes. The insect samples associated with these categorical habitats were completely enumerated using allocations of 4, 6, 8 or 10 samples at a time from various sample sizes to determine how different allocations affected the results. The mean was not affected, but the standard deviation decreased with increased allocation sizes in all habitats. The third scenario used the two observers and three habitat categories to create six additional complete enumeration distributions by allocating four samples at a time from groups of varying sample sizes. These enumeration distributions are non-parametric estimators of the sampling distribution of: (1) the sample averages of a given sample size when samples are taken from the entire field, (2) the sample averages of a given size when samples are taken from each cotton habitat or (3) the sample averages of a given sample size from samples taken from each habitat by each observer. To support the enumeration analyses, these insect samples were analyzed further by Poisson regression models. These models showed significant differences between TPB counts by the two observers and among the habitats, whereas the observer by habitat interaction was not significant. For every combination of observer and cotton growth category, a Poisson regression model estimated the mean rate of TPB numbers. These means were similar to the corresponding modes of the complete enumeration distributions. The two non-standard methods showed that TPB numbers differed by habitat categories even though there were samples with a zero count, whereas a correlation analysis failed to identify a relationship between TPB sample counts and unsupervized habitat classes.

Comparison of Direct and Indirect Sampling Methods for Tarnished Plant Bug (Hemiptera: Miridae) in Flowering Cotton

A complex of hemipterans, especially the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), has become a major target of insecticides in flowering cotton, Gossypium hirsutum L., in the mid-southern United States. Sampling protocols for this complex during this period of cotton development are poorly established, resulting in uncertainty about when infestations warrant treatment. Nine direct and indirect sampling methods were evaluated for bias, precision, and efficiency in cotton throughout the Mid-South during 2005 and 2006. The tarnished plant bug represented 94% of the bug complex in both years. Sweep-net and black drop-cloth methods were more efficient than other direct sampling methods, but they were biased toward adults and nymphs, respectively. Sampling dirty blooms was the most efficient indirect sampling method. The sweep-net, whole-plant, and dirty-bloom methods were more accurate than the other sampling methods evaluated based on correlations with other sampling methods. Variability attributed to the person collecting the sample was significant for all sampling methods, but least significant for the dirty-square method. Further research is needed to establish thresholds based on sweep-net, drop-cloth, dirty-square, and dirty-bloom sampling methods as these methods provide the best combinations of accuracy and efficiency for sampling tarnished plant bugs in cotton.

Comparison of Direct and Indirect Sampling Methods for Tarnished Plant Bug (Hemiptera: Miridae) in Flowering Cotton

A complex of hemipterans, especially the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), has become a major target of insecticides in flowering cotton, Gossypium hirsutum L., in the mid-southern United States. Sampling protocols for this complex during this period of cotton development are poorly established, resulting in uncertainty about when infestations warrant treatment. Nine direct and indirect sampling methods were evaluated for bias, precision, and efficiency in cotton throughout the Mid-South during 2005 and 2006. The tarnished plant bug represented 94% of the bug complex in both years. Sweep-net and black drop-cloth methods were more efficient than other direct sampling methods, but they were biased toward adults and nymphs, respectively. Sampling dirty blooms was the most efficient indirect sampling method. The sweep-net, whole-plant, and dirty-bloom methods were more accurate than the other sampling methods evaluated based on correlations with other sampling methods. Variability attributed to the person collecting the sample was significant for all sampling methods, but least significant for the dirty-square method. Further research is needed to establish thresholds based on sweep-net, drop-cloth, dirty-square, and dirty-bloom sampling methods as these methods provide the best combinations of accuracy and efficiency for sampling tarnished plant bugs in cotton.

Suppression of Tarnished Plant Bugs (Heteroptera: Miridae) in Cotton by Control of Early Season Wild Host Plants with Herbicides

Broadleaf weeds found in marginal areas by fields, roads, and ditches were controlled with herbicides in 23-km2 areas of the Mississippi Delta in March or April of 1999, 2000, and 2001. There were two treated and two untreated 23-km2 areas in each of the 3 test yr. The herbicides used were Trimec® or Strike 3™, and both contain mecoprop, 2, 4-D, and dicamba. Broadleaf weeds can serve as early season food and reproductive hosts for tarnished plant bugs, and population buildups can occur on these weeds before movement of plant bugs into cotton. Cotton fields in the treated sites and in untreated 23-km2 sites were sampled for tarnished plant bugs weekly during June and July of all 3 yr. Overall mean numbers of tarnished plant bugs were significantly lower in cotton in the treated areas. The average reduction in overall mean numbers of plant bugs was 50% for the 3-yr period. Grower costs for insecticides used to control plant bugs were lower in cotton in the treated test sites in all 3 yr. The average net savings in plant bug control costs was estimated at $35,477/yr for growers in the treated areas over the 3 yr of the study. Elimination of broadleaf weeds was found to be an effective method for reducing numbers of plant bugs in cotton. However, it did not reduce numbers of tarnished plant bugs in any year to a level in cotton where additional control with insecticides was not needed.

Efficacy of Various Insecticides Against Tarnished Plant Bugs in Cotton (Lab Trial), 1996

Abstract This test was designed to evaluate the effectiveness of various insecticides for control of TPB in cotton. Adult TPB were captured from flowering plants in the early spring before insecticide applications were initiated. Cotton plants were treated in the field, and immediately the terminals were cut and placed into water picks and transported to the lab. In the lab, 5 TPB adults were caged on the terminals, and allowed to feed for 24 h. The number of live and dead TPB was recorded. 48 hours after the plants were treated, additional terminals were cut, put in water picks and brought to the lab. TPB were placed on these in the same manner to test for the residual effect of the insecticide. Each treatment considered of 5 terminals with 5 TBP on each terminal. This was replicated four times for each treatment. Chemical application was made with a CO2 powered back pack sprayer with 1 TX 4 hollow cone nozzle per row traveling 4 mph delivering 5 gpa.

Efficacy of Various Insecticides Against Tarnished Plant Bugs in Cotton (Field Trial), 1996

Abstract This test evaluated the effectiveness of insecticides for the control of TPB in cotton. Plots were 8 rows wide and 50 ft long with 8 untreated rows or a 10 ft planted buffei between plots. Plots were sampled 3 DAT for TPB in squares. Twenty-five randomly selected squares in each plot were sampled by visually observing the number of TBP adults and nymphs in each square. An insecticide application was applied on 9 Aug with a high-clearance spray tractor equipped with two TX4 hollow cone nozzles per row traveling 4 mph and delivering 5 gpa. Plots within a replicate were sprayed sequentially to maintain true replicate integrity.

Efficacy of Chlorpyrifos-Methvl to Control Tarnished Plant Bug in Cotton, 1996

Abstract Cotton was planted 9 May on the Cotton Branch Experiment Station in Marianna, AR in 8 row (38 inch centers) wide plots 70 ft long with 10 ft alleys and separated by a 6.5 ft buffer planted in mustard. Treatments were arranged in a RCBD with 3 replications. Insecticides were applied 10 Jul using a 8-row CO2 charged hi-boy sprayer calibrated to deliver 10.5 gpa at 30 psi with TJ-60 8002 nozzles on 19 inch spacing. Prior to application, TPB were collected using sweep nets in blooming mustard. The collected TPB were placed in 15 ml plastic vials (5 insects per vial) on ice. Three organdy sleeve cages, 6 inches diam by 18 inches long, were secured to randomly selected individual plants in the center 2 rows by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil leaving plant terminals exposed. Following treatments, the foil was removed, the cage pulled up, and 5 TPB nymphs (3 to 5th instar) were placed into each cage. Cage tops were secured with twist ties. After 72 h plants were cut below the cage and taken to the laboratory where TPB mortality was determined. Mortality data were analyzed with AOV, and means separated with LSD.

Persistence of Mycotrol Wp9504 (Beauver1A Bassiana) and Provado (Imidacloprid) to Control Tarnished Plant Bug in Cotton, 1996

Abstract The persistence of Mycotrol and Provado alone and in combination to kill TBP caged on cotton plants was studied. Cotton was planted 20 May on the UA Agriculture Research and Extension Center, Fayetteville, AR. Adult TPB were collected 16 Jul from flowering mustard planted in cotton at the UA Cotton Branch Experiment Station, Marianna, AR and transported to Fayetteville, AR. Nylon tulle (1 mm2 mesh) sleeve cages 3 ft long by 1 ft diameter were placed over the first 6 terminal nodes of flowering cotton plants in plots 30 ft long by 1 row in width. Cages were separated across rows by 3 rows and within rows by 10 ft. A RCB design was used with 4 blocks and 3 cages per treatment within a block with 5 TPB per cage. Treatments were applied 17 Jul at 15 gpa with 0.04% Kinetic solution as carrier using a CO2 powered backpack sprayer at 35 psi with Twin Jet 8002 VS nozzles. The check was 0.04% Kinetic solution. Additional replicates were placed in the field 12, 24, and 48 h after spray. 72 h from first exposure, TBP were collected. Live TPB were placed in individual 30 ml plastic cups with a 2.5 cm piece of fresh green been and monitored for mortality 3, 5, and 7 DAT. Dead TBP were placed in sporulation chambers (9 cm Petri dishes with moist filter paper), sealed with Parafilm and examined after 1 week to assess mycoses. ANOVA and mean separation by LSD (P = 0.05) were performed using the arcsine/square root of the proportion dead from each cage.