Soil-applied Systemic Insecticides Research Articles

Foliar- and Soil-Applied Pesticide Compatibility with Aphidius colemani1 Parasitoids

When using predators or parasitoids for biological control of target pests, pesticides might be required to manage other arthropod pests and plant diseases. To minimize risk to natural enemies, growers need to be aware of which pesticides cause direct and indirect toxicity when combining biological and chemical controls. Aphidius colemani Viereck (Hymenoptera: Braconidae), an endoparasitoid of green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), and other aphid pests, killed after exposure for 6, 12, 24, and 48 hours to 13 contact insecticides and two fungicides at medium and high rates were assessed in a laboratory. In addition, percentage of parasitism of green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), after plants were treated with five soil-applied systemic insecticides was determined in a greenhouse. Using standards set by the International Organization for Biological Control-West Palearctic Regional Section (IOBC-WPRS), most foliar-applied pesticides tested were “slightly harmful” or “moderately harmful” to A. colemani. However, permethrin, spinetoram + sulfoxaflor, dinotefuran, tolfenpyrad, and acetamiprid killed ≥70% of A. colemani. In addition, the systemic insecticides cyantraniliprole, dinotefuran, flupyradifurone, imidacloprid, spirotetramat killed 100% of green peach aphids, thereby eliminating hosts for A. colemani to parasitize. Results underscore the need to develop new, practical guidelines for evaluating pesticide toxicity to natural enemies.

Efficacy of Soil-Applied Systemic Insecticides Against Tobacco Pests, 2014

Efficacy of several soil-applied insecticides (Table 1) was tested against key tobacco pests: TFB, TBW, GPA, and tobacco/tomato hornworms (HW). Two identical experiments were conducted at the Upper Coastal Plain Research Station (UCPRS) in Rocky Mount, NC, and the Lower Coastal Plain Research Station (LCPRS) in Kinston, NC. In each experiment, four replicates of the six treatments, including an untreated check, were arranged an RCB design. Each 0.018-acre plot consisted of four, ca. 25 plant, rows. At LCPRS, pre-transplant greenhouse tray drench (GTD) insecticide applications were made on 7 May 2014 in 1 L water using a CO2-pressurized sprayer fitted a single flat-fan nozzle. Twice the application volume was used to wash the material into the root zone immediately following treatment. GTD treatments were applied as above at UCPRS on 28 Apr. The plants were transplanted on 5 May at UCPRS and 8 May at LCPRS, and in-furrow transplant water (TPW) treatments were applied in ca. 160 gal/A of water using four 5-gal mini-tanks affixed to the planter. Plants received no additional insecticide treatments for the …

Soil Applied Systemic Insecticides for Control of Asian citrus psyllid in Newly Planted Citrus Trees

Orchard renewal is a special challenge where HLB is endemic.  Young trees are especially susceptible to the disease and continuously attractive to the psyllid vector due to frequent flushing.  Heavy reliance is placed on systemic insecticides to protect young trees.  However, all presently labeled for citrus are neonicotinoids (IRAC Group 4a) making resistance likely and the long term viability of this strategy questionable.  Rotation partners are needed to forestall selection for resistance. Therefore, we conducted a multiyear study to evaluate rotations of neonicotinoid insecticides rotated with cyantraniliprole a Group 28 insecticide in a block of ‘Hamlin’ orange on ‘US802’ rootstock planted in May 2010. Four treatment programs using two rates of Verimark 20 SC, rotated with Platinum 75 and Admire Pro in two different sequences were compared to an untreated check in an RCBD with 4 replicates.  Adult psyllid populations were monitored monthly and immatures counted when natural flush was present.  Incidence of HLB was assessed by PCR in Aug 2011, and Jan, May and Aug 2012. Psyllid populations on treated trees averaged 1.43 per tap compared to a range of 0 to 0.8 on treated trees.  Incidence of HLB reached 29% in Aug 2011 on untreated trees compared to 0-8.3% on treated trees.  In May 2012 these numbers had increased to 67 % and 11-26% respectively.  Diameter of scions was 33% larger on treated trees in Sep 2012.  Although effective, the 90 day treatment regimen was not enough to protect trees from HLB and additional strategies are necessary.

Variable concentration of soil‐applied insecticides in potato over time: implications for management of Leptinotarsa decemlineata

Select populations of Colorado potato beetle, Leptinotarsa decemlineata, in Wisconsin have recently become resistant to soil-applied neonicotinoids in potato. Sublethal insecticide concentrations persisting in foliage through the growing season may select for resistance over successive years of use. Over the 2 years of this study, the aim was to document the in-plant insecticide concentrations over time that result from four different types of soil-applied insecticide delivery for thiamethoxam and imidacloprid in potato, and to measure the impact upon L. decemlineata populations following treatments. After plant emergence, insect life stages were counted and plant tissue was assayed weekly for nine consecutive weeks using ELISA. Peak concentration of both imidacloprid and thiamethoxam occurred in the first sample week following plant emergence. The average concentration of both insecticides dissipated sharply over time as the plant canopy expanded 50 days after planting in all delivery treatments. Both insecticides were detected at low levels during the later weeks of the study. Among-plant concentrations of both neonicotinoids were highly variable throughout the season. Populations of L. decemlineata continued to develop and reproduce throughout the period of declining insecticide concentrations. Sublethal, chronic exposure to soil-applied systemic insecticides resulting from these delivery methods may accelerate selection for resistant insects in potato.

Evaluation of a Single Application of Neonicotinoid and Multi-Application Contact Insecticides for Flatheaded Borer Management in Field Grown Red Maple Cultivars

Abstract Two trials evaluated insecticides for flatheaded borer control and effect on red maple (Acer rubrum L.) cultivar growth over 4 years. Chrysobothris femorata (Olivier) was the only species reared from borer damaged maples during the study. Soil-applied systemic insecticides (acephate, imidacloprid, clothianidin, dinotefuran, and thiamethoxam) and trunk-applied contact insecticides (chlorpyrifos and bifenthrin) were tested. In the 2005 trial, a one-time drench of Allectus (imidacloprid + bifenthrin) or Discus (imidacloprid + cyfluthrin) provided 2 to 4 years of protection with ‘Autumn Flame’ and ‘Franksred’ from C. femorata. Soil-applied experimental imidacloprid tablets prevented borer damage in the third and fourth post-treatment years, but were not as effective as imidacloprid drenches in the first two years. Soil applied acephate tablets, chlorpyrifos (Dursban 4E) trunk sprays, or untreated control plants had borer damage each year, which totaled up to 41.7% damage by year 4 in ‘Autumn Flame’. Trunk diameter growth and tree canopy size was greater with Discus drench or imidacloprid tablet treatments than other treatments. In the 2006 trial, drenches of Allectus, Discus, or Safari 20SG (dinotefuran) applied in May and Discus or Arena 50WDG (clothianidin) drenches applied in March provided complete protection from C. femorata the first year in ‘Fairview Flame’, ‘Franksred’, and ‘October Glory’. Discus (March) drench provided four years of complete protection among the three cultivars, while other neonicotinoid drenches had 3.7–6.3% (Arena March), 3.7–12.5% (Arena May), 0–6.3% (Discus May), 0–10.3% (Safari), and 12.5–20.5% (Flagship) total damage. Ineffective treatments included an experimental imidacloprid gel (7.4–18.8% damage), acephate tablets (18.5–75.0%), Onyx Pro Insecticide (5.1–18.8%), Dursban 2E (11.1–31.3%), one imidacloprid tablet (15.4–43.8%), or untreated plants (32.1–41.0%). This study demonstrates a single application of some neonicotinoid treatments can provide multi-year C. femorata prevention, increased maple trunk growth, and provide borer protection superior to trunk sprays.

Effects of Horticultural Oil and Foliaror Soil-Applied Systemic Insecticides on Euonymus Scale in Pachysandra

The relative abilities of horticultural oil, acephate, and imidacloprid to control euonymus scale (Unaspis euonymi) throughout the canopy of Japanese pachysandra (Pachysandra terminalis) were compared. Distribution of scales and the level of parasitism were also determined. Horticultural oil gave the greatest level of control (99%) when applied in the dormant season followed by an application that targeted mobile stages of the insects during the summer. Summer applications of acephate gave good control (66%), while imidacloprid was not effective. Most of the live and parasitized scales were observed in the middle and basal portions of the plant canopy. Rates of parasitized scales never exceeded 25% in the control plots. Rates of parasitism were too low to distinguish differences among rates of parasitism in the 4 treatments.

Control of Silverleaf Whitefly on Staked Tomato with Foliar and Soil-Applied Systemic Insecticides, 1997

Abstract Greenhouse raised tomato seedlings were planted 11 Mar at 18-inch spacing on 4 pairs of subirrigated beds 32 inches wide and 240 ft long on 6-ft centers. Beds had been fertilized with 800 lb/acre of 5-16-8 dry bottom mix and 500 lbs/acre of 19-0-30 top mix banded on each side of the bed, fumigated with a 67/33% mixture of methyl bromide/chloropicrin at a rate of 2201b/acre and covered with black polyethylene film. Each bed was divided into four 60-ft-long plots. Seven treatments and an untreated check were assigned to the 8 plots of each pair of beds in RCB design with 4 replications. Plants were sprayed with a combination of Maneb 80 WP at 1 lb/acre plus Kocide 101 at 3 lb/acre for disease control and side dressed with 40 lb N/acre and 40 lb K/acre liquid fertilizer on 22 Mar. Three applications of NoMate® tomato pinworm pheromone were made 1,15, and 29 Apr. Tomatoes were staked and tied according to standard practices. Admire and CGA-293343 treatments were applied as a soil drench 24 May in 10 ml of solution to each plant. Foliar treatments, EXP 80667A 70 WP, EXP 61096A .83EC, and Provado were applied with a high-clearance sprayer utilizing a hydraulic pump operating at 200 psi and delivering the spray through two drop booms each equipped with 3 yellow hollow-cone Albuz® nozzles for a rate of 69 GPA. Five weekly foliar applications were initiated on 29 Apr after a count of adults on 22 Apr. The soil-drench treatments were also sampled 22 Apr. Sampling for adults in drench-treated plot began 22 Apr. and in foliar-treated plot the following week. Adult whitefly were sampled by a beat-pan method employing 9X13 inch metal cake pan painted black and covered with a 10% detergent/vegetable oil mixture. The total number of adults captured from one beat on four separate plants was counted as a subsample with 5 subsamples collected per plot. Nymphs were monitored in the field beginning 28 Apr. using a hand lens on the first date to examine 40 sq cm of a leaf from the 6-7th node. The number of small/medium or large/pupae were recorded for each single-leaf subsample with 5 leaves sampled per plot. Leaves were taken to the laboratory on the 2 subsequent sample dates and the number of dead or parasitized pupae was also noted.

Control of Honeysuckle Witches Broom Aphid with Soil-Applied Systemic Insecticides—A two Year Evaluation, 1993-1994

Abstract Trials were established during 1993 at the Colorado State University Horticulture Research Farm using one year-old nursery liners, planted in an irrigated field. Treatments were applied 26 May, 1993. Applications using a Kioritz® soil injector involved introduction of 28 ml of diluted insecticide into two injection holes at the base of each plant. Soil drench treatments involved pouring 400 ml of diluted insecticide around the base of the plant. Plots were arranged in a RCB design with 5 replications. Evaluations in 1993 were made by counting all symptomatic terminals and counting all associated aphids on 6 Jul. Trials the subsequent year involved counting the number of symptomatic (witches broom) terminals and making an assessment of plant quality on 9 Jun 1994. Throughout the experiment the field was periodically furrow irrigated.

Management of the Tobacco Aphid and Tobacco Budworm on Flue-Cured Tobacco, 1993

Abstract This experiment was conducted at the VPI and SU Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA, to evaluate TA and TBW control on flue-cured tobacco with various combinations of foliar and soil-applied systemic insecticides. Tobacco was transplanted into experimental plots, 8 X 40 ft (2 rows × 24 plants), 12 May. Ten treatments were established in a randomized complete block design with 4 replications. The Temik soil treatments were applied in 14-inch bands using a tractor-mounted Gandy granular applicator and immediately covered with 6 inches of soil during bed formation on 11 May. Foliar treatments were applied on 9 and 30 Jul using a CO2-pressurized backpack sprayer that delivered 27 gpa at 60 psi through 3, TX-10 nozzles/row. Production practices followed Virginia Cooperative Extension Service recommendations except for insect control. TA populations were estimated on the upper 4 leaves of 10 plants per plot before foliar treatments were applied and at 3, 7, 12, and 20 d after the first application and 4 and 11 d after the second application. TBW were reared in the laboratory on artificial media for 7 d and released at one BW/plant on 20 consecutive plants in the second row of each plot on 6 Jul. TBW on the infested plants were counted on the d before treatment and at 3, 6, and 12 DAT. Leaves were harvested, cured, weighed, and graded by a USDA/AMS inspector. This information was used to calculated tobacco yield and price. Data were analyzed by ANOVA and significantly different means were separated by DMRT. TA count data were transformed to Log10 (x + 1) and TBW counts were transformed to SQRT (x + 0.5) before ANOVA.

Management of the Tobacco Aphid and Tobacco Budworm, 1992:

Abstract This experiment was conducted at the VPI & SU Southern Piedmont Agricultural Experiment Station, Blackstone, VA, to evaluate tobacco aphid and tobacco budworm control on flue-cured tobacco with various combinations of foliar and soil-applied systemic insecticides. Tobacco was transplanted into experimental plots, 4 (1 row) x 40 ft, on 13 May. Ten treatments were established in a RCB design with 4 replications. Plots were separated by single untreated guard rows. Temik soil treatments were applied in 14-inch bands using a tractor-mounted Gandy granular applicator and were immediately covered with 6 inches of soil at bed formation on 6 May. Foliar treatments were applied on 25 Jun and 21 Jul using a CO2-pressurized backpack sprayer that delivered 26 gal/acre at 60 psi through 3, TX-10 nozzles/row. Tobacco aphid populations were estimated on the upper 4 leaves of 10 plants per plot about once a wk from 4 to 12 wks after transplanting. Tobacco budworms were collected from untreated field tobacco and released at the rate of 1 budworm/plant on each of 15 plants/plot on 24 Jun. Budworms were counted on the 15 plants at 2, 7 and 14 DAT. Leaves were harvested, cured, weighed, and graded by a USDA/AMS inspector. This information was used to calculate tobacco yield and price. Data were analyzed by ANOVA and significantly different means were separated by DMRT (P = 0.05). Aphid count data were transformed to Log10 (x + 1). before ANOVA.

Evaluation of soil-applied systemic insecticides against cabbage aphid, Brevicoryne brassicae (L.), and resultant survival of the primary parasitoid, Diaeretiella rapae (McIntosh), on cabbage.

Evaluation of soil-applied systemic insecticides against cabbage aphid, Brevicoryne brassicae (L.), and resultant survival of the primary parasitoid, Diaeretiella rapae (McIntosh), on cabbage.

Control of the Onion Maggot with Soil Applied Systemic Insecticides, 1985

Abstract ‘CIMA’ onions were planted at the University of Idaho SW Idaho Research and Extension Center, Parma, ID, in Vickery-Marsing silt loam soil on 5 Apr. Thirteen-ft plots were planted using a ‘Planet Jr.’ push-type planter in a randomized complete block design with 5 replications. Insecticides were applied in-furrow at planting. A stand count was taken on 25 May to determine percent germination. Bulbs were lifted and topped on 30 Sep, and placed in storage 4 Oct.

Control of Potato Insects with Soil Applied Systemic Insecticides, Greeley, Co, 1984

Abstract Potatoes were planted 15 May at the Northern Colorado Research Center, Greeley, CO. Soil type was a sandy clay loam, 1.1% organic matter and a pH of 7.8. Plot size was 25 row-ft (30-inch row spacing), randomized in a complete block design with 4 replications. Insecticides were banded below the seed piece at planting. Insect counts were made 9 Jul by counting insects on 20 leaves/plot.

Control of Honeylocust Pod Gall Midge with Soil Applied Systemic Insecticides, Ft. Collins, Co, 1984

Abstract Recently transplanted honeylocust trees, 6-8 ft in height, were monitored for honeylocust pod gall midge activity at the Fort Collins City Nursery. When oviposition activity of the third generation was observed (22 Jun) soil systemic insecticides were applied, 3-5 inches deep, around the base of the trees. Rates of insecticides used were equivalent to that for elm leaf beetle control, i.e., 0.33 oz/trunk diameter inch. Plot size was a single tree, replicated 4 times, and arranged in a RCB design. Plots were evaluated 6 Jul by counting all new galls on the first, third, and fifth lower terminals. A second application was made 11 Jul for control of the “fourth” generation. This was followed by a 31 Jul evaluation where all new galls on the tree were counted.

Control of Colorado Potato Beetle with Soil Applied Systemic Insecticides, 1984

Abstract Potatoes were planted 15 May ’84 in declo silt loam soil. Plots consisting of 8 treatments and 4 replications were 4 rows X 25 ft and arranged in a randomized complete block design. “At-planting” treatments (*) were placed in the planting row. Late treatments (**) were side dressed 6 inches deep and 4 inches to the side of potato plants 7 wk after planting.

Birch, Evaluation of Soil-Applied Systemic Insecticides for Control of Fall Webworm Caterpillars and Japanese Beetle Adults, Wayne Co., Oh, 1984

Abstract Trees (6.4-8.9 cm dbh) growing in an experimental birch planting and infested with at least 1 webworm nest were chosen for evaluating soil-applied Standak and Di-Syston for control of fall webworm and Japanese beetles. Soil from the base of each tree to its dripline was cultivated prior to and following application of insecticides. Standak treatments were applied with a sprinkling can at the rate of ca. 545 ml of water/m2 of soil surface. Di-Syston granules were applied in salt shaker fashion to the treatment area, raked-in, and then watered as above. All treatments were applied to 4 single-tree replicates on 31 Jul, 5 days after a 3 cm rainfall, so soil moisture was adequate for movement and uptake of systemic insecticides. During the first and second weeks after application, 4.75 and 3.4 cm of rain fell, respectively, on the experimental area. There was no rain during the third week. Treatment effects were evaluated weekly by observing webs for presence of living fall webworm larvae and for evidence of web expansion. A terminal lateral twig was removed from each treated tree and placed in a 1 liter fonda cup with 5 Japanese beetle adults in the laboratory at weekly intervals for 3 wk after application. Living and dead beetles were counted 48 h after caging.

Birch, Evaluating Soil-Applied Systemic Insecticides for Control of Birch Leafminer, Wayne Co., Oh, 1984

Abstract Efficacy of Standak and Di-Syston was evaluated against birch leafminer on 3- to 4-m-tall birch trees growing in an experimental planting at The Ohio State University, Ohio Agricultural Research and Development Center near Wooster. Standak was applied with a watering can at the rate of 545 ml/m2 of soil surface beneath the entire dripline of 4, single-tree replicates. Di-Syston was applied salt shaker fashion and watered-in at the same rate. Soil beneath all trees was cultivated prior to and immediately following application. Treatments were applied 7 May under cloudy skies at 18°C with a breeze of 8-15 kph. Treatment effectiveness was evaluated 18 June by removing 10 leaves at random from 1 dominant lateral twig per tree and counting the number of mined leaves.

Green Peach Aphid Control with Soil Applied Systemic Insecticides, 1983

Abstract Potatoes were planted 10 May, in 36 in rows in Declo silt loam soil. Treatments were applied to 4-row plots, 30 ft long randomized in complete blocks with four replications. The systemic insecticides were applied at planting in the seed row, or sidedressed at plant emergence. Green peach aphids were recorded from center two rows by counting total number of aphids on 20 compound leaves.

Control of Potato Insects with Soil Applied Systemic Insecticides, 1983

Abstract ‘Russet Burbank’ potatoes were planted 21 Apr. at Parma, Idaho, in Greenleaf-Owyhee silt loam soil. Plots were 25 ft long and 2 rows wide with 5-ft buffers. Treatments were arranged in a randomized complete block design. Chemicals were placed in the planting furrow. Counts were taken weekly during the period of significant insect activity. Beetle numbers were estimated by walking between the rows and recording larvae and adults that could be seen without moving foliage. Aphid numbers were based on a 25-compound leaf sample from each plot.

Potato Pest Control with Soil Applied Systemic Insecticides and Foliar Insecticidal Sprays, 1982

Abstract ‘Russet Burbank’ potatoes were planted 20 May, at the Rosemount Agric. Exp. Stn., Dakota Co., Minn. Plots were four rows wide, 60 ft long with a 40-inch spacing between rows and 10 inches between plants. The experiment was arranged in a randomized complete block design with four replications. Two untreated rows separated each plot. Bravo fungicide was applied weekly per label recommendation from 2 June to the end of the season.