Foliar Insecticide Applications Research Articles

Foliar- and Seed-Applied Insecticides for Management of Melanaphis sorghi (Hemiptera: Aphididae) in Alabama

Abstract Following the emergence of Melanaphis sorghi (Theobald) (Hemiptera: Aphididae) as a new pest of sorghum in the United States, research was conducted to identify tools and techniques successful at reducing populations and preventing economic losses in grain sorghum, Sorghum bicolor (L.) Moench. The objective of this study was to assess the efficacy of seed- and foliar-applied insecticide treatments for management of M. sorghi. Small plot experiments were replicated at two locations to evaluate residual activity of neonicotinoid seed treatments and foliar insecticides. Natural enemy presence was recorded in each of these trials to determine which predator and parasitoid species were using M. sorghi as prey. All seed treatments suppressed M. sorghi populations below a treatment threshold of 75 aphids per plant for 30% of plants for >6 weeks after planting. Foliar insecticides including flupyradifurone, sulfoxaflor, and thiamethoxam provided 3–4 weeks of population suppression, irrespective of M. sorghi pressure. Fifteen natural enemy species were identified in this study, and community structure varied temporally and geographically. In general, natural enemy species richness was correlated with aphid abundance. We identified the most efficacious insecticides available for management of M. sorghi and determined that they should be compatible with biological control and integrated pest management programs.

Response of long duration pigeonpea (Cajanus Cajan L .) to foliar application of nutrients and insecticides under rainfed condition of Bihar

Response of long duration pigeonpea (Cajanus Cajan L .) to foliar application of nutrients and insecticides under rainfed condition of Bihar

Field-evolved pyrethroid resistance in Tychius picirostris (Coleoptera: Curculionidae) populations in Oregon white clover seed crops.

The clover seed weevil, Tychius picirostris Fabricius, a serious pest of white clover, Trifolium repens L., grown for seed in western Oregon, causing feeding damage to flowers and developing seeds. Since 2017, white clover seed producers have anecdotally reported T. picirostris control failures using foliar pyrethroid insecticide applications. This mode of action (MoA) is an important chemical control option for T. picirostris management. To evaluate insecticide resistance selection to pyrethroids (bifenthrin) and other MoAs labeled for T. picirostris management (malathion and chlorantraniliprole), adult populations were collected from 8 commercial white clover grown for seed fields in the Willamette Valley, OR, in 2022 and 2023. Among collected Oregon populations, very high resistance ratios (RR50 = 178.00-725.67) were observed to technical grade bifenthrin and low to high resistance ratios (RR50 = 7.80-32.80) to malathion in surface contact assays compared to a susceptible Canadian field population. Moreover, >2.73 times the labeled rate of formulated product containing bifenthrin as the sole MoA was required to kill >50% of T. picirostris in topical assays. Synergistic assays with a mixed-function oxidase inhibitor, an esterase inhibitor, and a glutathione-S-transferase inhibitor revealed phase I and II detoxification enzymes are present in Oregon T. picirostris populations and confer metabolic resistance to bifenthrin. This is the first report of T. picirostris insecticide resistance selection to pyrethroid and organophosphate insecticides. Results will inform continued monitoring and insecticide resistance management strategies to slow the evolution of T. picirostris insecticide resistance selection in Oregon's white clover seed production.

Efficacy of foliar-applied insecticides on thrips in Mississippi cotton, 2023

Efficacy of foliar-applied insecticides on thrips in Mississippi cotton, 2023

Efficacy of foliar-applied insecticides on bollworm in cotton II, 2023

Efficacy of foliar-applied insecticides on bollworm in cotton II, 2023

Efficacy of foliar-applied insecticides and tank mixes on redbanded stink bug in soybean (Test 1), 2022

Efficacy of foliar-applied insecticides and tank mixes on redbanded stink bug in soybean (Test 1), 2022

Effects of Insecticide Drench Application against Immatures of Systena frontalis in Container-grown Hydrangea paniculata

Systena frontalis (F.) (Coleoptera: Chrysomelidae), commonly referred to as the redheaded flea beetle, is a serious pest in container nurseries, as adult feeding defoliates nursery crops and affects plant salability. Because the foliar application of insecticides provides inconsistent efficacy, additional and alternative control tactics are sought to target immatures of this pest in growing media. Thus, the objective was to determine the effects of non-neonicotinoid insecticides applied as a drench to growing media on immatures of S. frontalis. In 2021 and 2022, nine active ingredients were evaluated in four trials in a Georgia nursery and at a Virginia research and extension center. If available, the maximum label rates for flea beetles or other coleopteran pests were applied once to Hydrangea paniculata Siebold containers (11.4 L, 3 gal) as a drench application. The emergence of S. frontalis adults from treated growing media and foliar feeding damage was lower for the tetraniliprole (TetrinoTM) and spinetoram + sulfoxaflor (XXpire®) treatments than for nontreated plants. Cyclaniliprole (SarisaTM) and chlorantraniliprole (Acelepryn®) suppressed S. frontalis adult eclosion with less feeding damage than the nontreated plants. Tetraniliprole, spinetoram + sulfoxaflor, and cyclaniliprole are not labeled for drench application. Dinotefuran (Safari®) effectively reduced adult emergence and feeding damage. Species used in this study: Redheaded flea beetle, Systena frontalis (F.); panicled hydrangea, Hydrangea paniculata Siebold. Chemicals used in this study: Cyantraniliprole (Mainspring®GNL), chlorantraniliprole (Acelepryn®), tetraniliprole (TetrinoTM), cyclaniliprole (SarisaTM), Spinetoram + Sulfoxaflor (XXpire®), tolfenpyrad (Apta®), Chromobacterium (Grandevo®CG), flupyradifurone (AltusTM), dinotefuran (Zylam® Liquid, Safari® 20G), and polyterpenes pinene (NuFilm® P).

Palmer Amaranth (Amaranthus palmeri) Control in Dicamba-Tolerant Cotton (Gossypium hirsutum) when Applied with Various Dicamba + Insecticide Tank-Mixtures

Postemergence herbicide application timings for Palmer amaranth (Amaranthus palmeri) often coincide with foliar insecticide applications in cotton (Gossypium hirsutum). Combining multiple pesticides into a single application increases efficiency while reducing overall application cost. Multiple foliar insecticides are now labeled for dicamba tank-mixes. However, there is limited literature with respect to efficacy of dicamba on Palmer amaranth control when applied with insecticides. Field experiments were conducted from 2018 to 2020 to evaluate the effect of carrier volume and insecticide on the efficacy of dicamba (XtendiMaxTM with VaporGripTM) to control Palmer amaranth in XtendFlex™ cotton production systems. Dicamba was tank-mixed with acephate and dimethoate to four-leaf cotton and with thiamethoxam and sulfoxaflor just prior to bloom. Applications were made at carrier volumes of 140 and 280 L ha-1 and with a single spray droplet size of 800 µm. Palmer amaranth control 7 d after treatment was negatively impacted when applications included dimethoate; however, no corresponding response in seedcotton yield was observed relative to dicamba applied alone. However, when pooled over carrier volume, applications containing dicamba + acephate resulted in higher seedcotton yield than applications of dicamba + dimethoate. Additionally, pre-bloom applications of dicamba + thiamethoxam or sulfoxaflor increased Palmer amaranth efficacy relative to dicamba applied alone. Although certain insecticides are known to increase herbicidal crop response, the impact of insecticides on herbicide efficacy to control specific weed species is largely unknown. Therefore, we conclude that multiple dicamba + acephate, thiamethoxam, or sulfoxaflor tank-mixtures provide similar control of Palmer amaranth compared to dicamba alone.

Development of economic thresholds for pea aphid (Hemiptera: Aphididae) management in lentil (Fabaceae) based on in-field insecticide efficacy trials.

Pea aphid (Acyrthosiphom pisum Harris, Hemiptera: Aphididae) presents a significant economic challenge to lentil (Lens culinaris Medik.) production in the major growing region of Saskatchewan, Canada. During 2019-2020, field experiments were conducted to optimize the management tools for pea aphid control on lentils. A randomized split-plot design was used with main plots consisting of different pea aphid pressures and subplots consisting of different insecticide treatments. The main plot design was aimed to assess the impact of A. pisum feeding on lentil yields during the late vegetative to early reproductive stages. Subplots of the study evaluated the efficacy of 3 insecticides in suppressing pea aphid populations on lentils. Lentil is susceptible to A. pisum feeding and requires management at low pest densities. The economic threshold for pea aphids on lentil crops varied depending on environmental conditions, ranging from 20 to 66 aphids per sweep, calculated using a discrete daily growth rate of 1.116. The estimated economic thresholds provided a 7-day lead time before aphid populations achieved the economic injury level (EIL). The EIL was defined as 78 ± 14 aphids per sweep net sample or 743 ± 137 cumulative aphid days from the first aphid present in the field. In addition, the results of the study found that, on average, foliar applications of insecticides containing the pyrethroid active ingredient lambda-cyhalothrin (IRAC group: 3A) reduced pea aphid populations by 83% compared with untreated control.

Characterization of western corn rootworm (Coleoptera: Chrysomelidae) susceptibility to foliar insecticides in northeast Nebraska.

Foliar-applied insecticides are commonly used for adult western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), control in Nebraska but little efficacy data is available. Anecdotal reports of reduced efficacy in areas of northeast Nebraska led to the conduct of this study. Objectives were to (i) evaluate the efficacy of commercial applications of commonly used formulated insecticides (bifenthrin, lambda-cyhalothrin, chlorpyrifos, or tank mixes) for WCR control in 7 northeast Nebraska counties during 2019 and 2020 and (ii) conduct adult WCR concentration-response vial bioassays with bifenthrin, chlorpyrifos, and dimethoate active ingredients on a subset of field populations. Whole plant counts (WPC) were used to measure WCR densities in insecticide-treated and untreated maize fields before and after insecticide application. Field control was excellent with organophosphate/pyrethroid tank mixes as proportional change in mean WPC of treated fields was significantly reduced (>0.90) versus untreated fields where little change in WPC occurred. The exception was one treated Boone County field where proportional reduction in WPC was ≤0.78. Bioassays revealed LC50s and resistance ratios of most populations exposed to bifenthrin and dimethoate were not significantly different than the susceptible control. Most populations exhibited a low level of chlorpyrifos resistance when compared to the susceptible control. Field and lab data suggest the local onset of practical WCR field-evolved resistance to bifenthrin in Boone County and chlorpyrifos in Boone and Colfax counties. Results of this study will increase our understanding of WCR resistance evolution, serve as a comprehensive baseline for future research, and inform WCR management programs.

Effect of maize seed treatment on oviposition preference, larval performance and foliar damage of the fall armyworm

AbstractThe fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith; Lepidoptera: Noctuidae), is an invasive pest that has recently become a major worldwide threat for maize production. Greatest crop yield reductions occur following damage by FAW larvae at early vegetative plant stages, between the first and second week after plant emergence. In this study, field and semi‐field experiments were carried out to assess the effect of cyantraniliprole‐based seed treatment on the protection of early stages of maize plants against FAW and the associated mechanisms. In the field, maize seed treatment using cyantraniliprole (Fortenza®) significantly reduced the percentage of infested seedlings (77%) and the percentage of seedlings with severe damage (86%) up to 3 weeks after emergence. In a choice situation, semi‐field experiments showed that gravid moths preferred to lay eggs on plants from untreated seeds (68%) rather than on plants from treated seeds. To the best of our knowledge, this is the first evidence that insecticide residues present in plant tissues deter oviposition of Noctuid moths. Seed treatment with cyantraniliprole also reduced plant infestation (65%) 10 days after artificial inoculation of neonate larvae at 3 weeks after plant emergence, reducing the severity of leaf damage (by 67%). Insecticide seed treatment is a relevant tool for the integrated pest management of the FAW in high‐value crops such as sweet corn, especially for reducing foliar applications of insecticides during the most susceptible stages of the crop, as far as the risk of impacts on non‐target organisms is low and no alternative biocontrol option is available.

Efficacy of selected foliar applications of insecticides against soybean looper in soybeans, 2021

Efficacy of selected foliar applications of insecticides against soybean looper in soybeans, 2021

Evaluation of foliar insecticide applications for cotton fleahopper control in cotton, 2023

Evaluation of foliar insecticide applications for cotton fleahopper control in cotton, 2023

Evaluating Foliar Insecticide Applications and Seed Treatments for Onion Maggot Control in Onion, 2022

Evaluating Foliar Insecticide Applications and Seed Treatments for Onion Maggot Control in Onion, 2022

Evaluation of foliar insecticide applications for thrips control in seedling cotton, 2023

Evaluation of foliar insecticide applications for thrips control in seedling cotton, 2023

Comparison of Soil- and Foliar-Applied Insecticides for Control of Silverleaf Whitefly on Watermelon, 2022

Comparison of Soil- and Foliar-Applied Insecticides for Control of Silverleaf Whitefly on Watermelon, 2022

Control of Diamondback Moth on Cabbage With Labeled and Experimental Foliar-Applied Insecticides 2022

Control of Diamondback Moth on Cabbage With Labeled and Experimental Foliar-Applied Insecticides 2022

Control of Leaffooted Bug in Cotton Using Foliar-Applied Insecticides, 2022

Control of Leaffooted Bug in Cotton Using Foliar-Applied Insecticides, 2022

Impact of Planting Date and Insecticide Application Methods on Melanaphis sorghi (Hemiptera: Aphididae) Infestation and Forage Type Sorghum Yield.

Studies on the management of the invasive Melanaphis sorghi are essential to refining integrated pest management strategies against M. sorghi in forage sorghum in the USA. The objective of this study was to determine the impact of planting date (early planting and late planting) and in-furrow and foliar insecticide application of flupyradifurone, on M. sorghi infestation and forage sorghum yield in Tifton, Georgia and Florence, South Carolina, USA, in 2020 and 2021. Early planted sorghum supported slightly higher aphid density and severity of infestation as evident in the greater cumulative insect days values in the early planted sorghum at both Florence and Tifton in 2020 and 2021. A single foliar application reduced aphid infestations below the threshold level of 50 aphids per leaf. In contrast, in-furrow insecticidal application in selected plots at both locations significantly suppressed M. sorghi density to near-zero levels. Yield results in Florence in 2020 showed that sorghum yield was over 50% greater in early planted plots compared to late planted plots. Both insecticide treatments (foliar and in-furrow) resulted in significantly higher yield than untreated plots. These data indicate that early planting coupled with in-furrow and foliar insecticide applications can suppress M. sorghi infestations and improve silage production in forage sorghum in the USA.

Management of Melanaphis sorghi (Hemiptera: Aphididae) in grain sorghum with early planting and in-furrow flupyradifurone application

Melanaphis sorghi is a key pest of sorghum production across the southern USA, where it causes serious damage that can lead to 100% grain yield loss in severe situations. Studies aiming to refine IPM strategies are crucial to improve management of this invasive pest. Here, the authors investigated the impact of planting date and insecticide application methods, including in-furrow vs. foliar applications, on M. sorghi infestation and grain sorghum yield. Field trials with four insecticide treatments (untreated, flupyradifurone in-furrow at 117 g/ha, flupyradifurone in-furrow at 146 g/ha, and flupyradifurone foliar at 73 g/ha) and two planting dates (mid-April to early May = early planting and late May to early June = late planting) were conducted on grain sorghum at Tifton, Georgia and Florence, South Carolina, in 2020 and 2021. Generally, early planted sorghum supported higher aphid density and severity of infestation as evident in the greater cumulative insect days in early planted sorghum in both Florence and Tifton. While a single foliar insecticide application immediately reduced infestations below the economic threshold, the lower rate in-furrow insecticide application significantly suppressed aphid density to near zero levels. These results suggest that foliar insecticide applications suppressed aphid densities, but were less consistent compared to in-furrow applications. Early planting dates and in-furrow insecticide treatments resulted in highest grain yield in both study locations. These data strongly suggest that planting early and using an in-furrow insecticide is the most consistent way to suppress M. sorghi infestations and improve grain yield in sorghum production in southern USA.