Control Of Japanese Beetle Research Articles

Antifeedant and insecticidal effects of alfalfa saponins in the management of the Japanese beetle Popillia japonica

AbstractPopillia japonica is a quarantine pest of priority interest for the EU, given its potentially important economic, social and environmental impacts. Alternative strategies to chemical methods are essential to limit its spread in newly infested areas with favourable climatic and environmental conditions. Saponins are biologically active molecules widely distributed in plants, displaying a well‐known repellent activity combined with a mortality effect against insects. In this context, saponins were extracted from alfalfa Medicago sativa, where medicagenic and zanhic acid glycosides and Soyasaponin I were the most abundant compounds and used in the laboratory and semi‐field experiments for treating leaves of susceptible host plants for P. japonica. Under laboratory conditions, a food deterrence effect and a significant mortality rate were observed using Corylus avellana leaves treated at increasing saponin concentrations, ranging from 1% to 5% w/v. Semi‐field condition experiment supported the food deterrence effect, as a significant food preference was observed for untreated plants of Vitis vinifera compared to treated plants. The promising results obtained suggest that alfalfa saponins could represent a potential eco‐friendly approach for Japanese beetle control.

Control of Japanese Beetles in Soybean with Foliar-Applied Insecticides and Insecticide/Fungicide Combinations, 2014: Table 1

We established one trial near Morrison, IL, to evaluate the efficacy of foliar-applied insecticides and insecticide/fungicide combinations to control Japanese beetles. The experimental design was an RCB with four replications. The plot size for each treatment was 10 ft (four rows) × 20 ft. The trial was planted on 23 May using a 16-row, Case IH Model 1240 Early Riser planter. Seeds were planted at a rate of 155,600 seeds/acre in 30-inch rows at an approximate depth of …

Evaluation of Metarhizium brunneum F52 (Hypocreales: Clavicipitaceae) for Control of Japanese Beetle Larvae in Turfgrass.

Experimental and commercial preparations of Metarhizium brunneum (Petch) strain F52 were evaluated for control of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarbaeidae), larvae (white grubs) in the laboratory and under field conditions. Experimental preparations consisted of granule and liquid formulations made using in vitro produced microsclerotia, which are intended to produce infective conidial spores after application. These formulations were compared against commercial insecticides (imidacloprid and trichlorfon), and commercial formulations of M. brunneum F52 (Met 52) containing only conidia. Field-collected grubs were susceptible to infection in a dosage-dependent relationship when exposed to potting soil treated with experimental microsclerotia granules in the laboratory. The LC(50) for field-collected larvae was 14.2 mg of granules per cup (∼15 g granules/m(2)). Field plots treated with experimental and commercial formulations of M. brunneum F52 after 10 September (targeting second and third instar grubs) had significantly lower grub densities compared with untreated plots, providing 38.6-69.2% control, which sometimes equaled levels of control with chemical insecticides. Fungal treatments made prior to 21 August provided 14.3-69.3% control, although grub densities resulting from these treatments were often not significantly lower than those in untreated control plots. By comparison, chemical insecticide treatments provide 68-100% grub control, often providing better control when applied earlier in the season. In conclusion, P. japonica larvae are susceptible to infection by M. brunneum, and grub densities were reduced most consistently by fall applications targeting later instars.

Effectiveness of Hand Removal for Small-Scale Management of Japanese Beetles (Coleoptera: Scarabaeidae)

Hand removal is often recommended as a method for small-scale control of Japanese beetles (Popillia japonica Newman). In this study, we investigated the effectiveness of daily hand removal for controlling damage by Japanese beetles on grape plants. We also investigated whether the timing of the removal (at 0800, 1400, or 1900 hours, or at all 3 periods) influenced the effectiveness of the technique. We found that hand removal significantly lowered the number of beetles on, and consequently the damage to, grape plants relative to nonremoval controls. Of the single removal treatments, removal of beetles at 1900 hours was most effective, with results similar to removing beetles three times per day. The majority of beetles removed from plants during the experiment were female, a pattern that matches our understanding of aggregation formation behavior in the species, and which may serve to enhance the benefits of hand removal. Hand removal seems to work by decreasing the number of feeding beetles, which in turn reduces the release of aggregation kairomones from the plant, and subsequently decreases the attractiveness of the plant to future beetles.

Preharvest Quarantine Treatments of Chlorantraniliprole, Clothianidin, and Imidacloprid-Based Insecticides for Control of Japanese Beetle (Coleoptera: Scarabaeidae) and Other Scarab Larvae in the Root Zone of Field-Grown Nursery Trees

Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), is an important quarantine pest of nurseries. Nursery plant movement from P. japonica-infested regions is regulated by the U.S. Domestic Japanese Beetle Harmonization Plan (DJHP), which classifies states by risk categories. Treatments for category 2 states include preharvest soil surface treatment of nursery plants grown in field soil using Discus SC, Marathon (1G or 60 WP), or Flagship (0.22G or 25 WG). In this study, Discus, Marathon 60 WP, or Flagship 0.22G DJHP standards were compared with labeled rates of non-DJHP-approved insecticides, including neonicotinoids clothianidin (Arena 50WDG), generic imidacloprid (Quali-Pro Imidacloprid 2 F T&O Insecticide, Mallet 2 F T&O Insecticide, and Lada 2 F Insecticide), and imidacloprid + bifenthrin (Allectus SC), as well as the anthranilic diamide, chlorantraniliprole (Acelepryn Insecticide). Arena provided 100% P. japonica control in May, June, and July over four test years, but had one larva recovered during August in two of those 4 yr. Acelepryn did not provide DJHP-acceptable P. japonica control. During July, Allectus provided 100% P. japonica control in three of four test years, but had four larvae in one test year. Other treatments tested only during July, which provided 100% P. japonica control, included Discus (five tests); Marathon, Quali-Pro, and Mallet (two tests); and Lada and Flagship (one test). Generic imidacloprid 2 F formulations were equivalent in P. japonica control to DJHP-approved insecticides. Insecticides generally performed poorly on other scarabs or curculionid larvae. The study supports Arena, Allectus, and generic imidacloprid 2 F products as suitable candidates for the DJHP.

Surface‐applied insecticide treatments for quarantine control of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), larvae in field‐grown nursery plants

Japanese beetles, Popillia japonica Newman, are a quarantine challenge for nursery shipments from infested to non-infested states. Marathon (imidacloprid) and Discus (imidacloprid + cyfluthrin) are approved preharvest nursery treatments (US Domestic Japanese Beetle Harmonization Plan; DJHP). This study evaluated approved and non-approved (acephate, carbaryl, clothianidin, dinotefuran, halofenozide, thiamethoxam, trichlorfon) preharvest treatments, optimal rates (labeled 1x, 0.3-0.75 x or 2-3 x) and optimal timings (June, July, August and September) to control early-instar (grubs) P. japonica in field nurseries. Most insecticides effectively reduced grub densities, except for acephate, carbaryl and trichlorfon. Clothianidin, thiamethoxam and halofenozide provided grub control equivalent to DJHP standards during most years. Across all test years and timings, percentage grub reductions were: Marathon (1x: 59.2-100; 3 x: 78.9-100), Discus (1x: 60.7-100), clothianidin (1x: 96.1-100; 3 x: 97.4-100), thiamethoxam (1x: 75.0-100; 3 x: 80.0-100), halofenozide (1x: 70.0-100; 3 x: 90.0-100) and dinotefuran (1x: 13.2-88.2; 3 x: 71.1-93.4). July application was more consistent and effective than other timings, and higher rates (2x and 3 x) did not generally improve grub control. Overall, clothianidin, thiamethoxam and halofenozide (and dinotefuran applied in August) were equivalent to current DJHP standards. These insecticides may be suitable for DJHP Category 2 states, potentially lowering grower costs.

Relative effectiveness of acid lead arsenate and other materials as stomach poisons for the larvae of the Japanese beetle.

Provides the results of experiments conducted from 1929 to 1936 to test the efficacy of acid lead arsenate and other insecticides for control of Japanese beetles.

Grape Cultivar Feeding Preference of Adult Japanese Beetles

The Japanese beetle is a major insect pest of grapes in the eastern United States. An examination of Japanese beetle preference for currently grown grape cultivars would be useful to growers in developing pest control strategies with reduced chemical inputs. The objective of this study was to examine grape cultivar preference of Japanese beetles for commercially available grape cultivars in both cage choice and field experiments. Outdoor cage choice screening studies included 32 grape cultivars from various Vitis species and were conducted at the Kentucky State University Research Farm in Frankfort, KY. Feeding preference was determined by examining incidence of damage (percent of leaves damaged per vine) and leaf area loss, which was rated as 0 pt, 0%; 1 pt, 1% to 10%; 2 pt, 11% to 20%; 3 pt, 21% to 30%; 4 pt, 31% to 40%; 5 pt, 41% to 50%; 6 pt, 51% to 60%; and 7 pt, more than 60%, by leaf position from the first (shoot tip) to 10th leaves. Analysis of variance indicated that there were significant differences in Japanese beetle leaf damage for cultivar and leaf position main effects. Leaf damage by Japanese beetles varied by leaf position on the shoot, with the fourth through sixth leaves from the tip with the most severe damage. Generally, cultivars showing an incidence of damage greater than 70% were either European or French hybrid cultivars, and those with less than 70% incidence of damage were either American cultivars or American cultivars with a V. labrusca background. The grape cultivars Marquis, Reliance, Catawba, Concord Seedless, Concord, Edelweiss, and Einset showed promise as selections for growers interested in reduced chemical inputs for control of Japanese beetles.

Knockdown, Residual, and Antifeedant Activity of Pyrethroids and Home Landscape Bioinsecticides Against Japanese Beetles (Coleoptera: Scarabaeidae) on Linden Foliage

Residual toxicity and leaf protection capability of five pyrethroids, professional and home garden azadirachtin formulations, and six other bioinsecticides for the home landscape were evaluated against the Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), on linden, Tilia cordata L. Capacity of intoxicated beetles to recover and subsequently feed and disperse also was evaluated to provide insight on activity characteristics of the different compounds. Intact shoots were sprayed and left in the field for varying intervals before being challenged with beetles in no-choice and choice tests. All pyrethroids except permethrin gave greater leaf protection, knockdown, and kill than did carbaryl, the standard, after 14 d of weathering. Deltamethrin, cyfluthrin, bifenthrin, and lamda-cyhalothrin gave a high level of protection for at least 19 d, and azadirachtin (Azatin XL) deterred feeding in choice tests for as long as 14 d. Home garden formulations containing pyrethrins in canola oil (Pyola) or azadiractin (Neem-Away) gave good short-term (< 3-d) protection. Formulations of capsaicin, rotenone + pyrethrins, kaolin particle film, D-limonene, or garlic extract were ineffective, the latter two formulations being highly phytotoxic to linden. Results of this study should help support updating of guidelines for insecticidal control of Japanese beetles.

Influence of Commercially Available Wildflower Mixes on Beneficial Arthropod Abundance and Predation in Turfgrass

Abstract Conservation and augmentation of indigenous natural enemies are promising strategies for biologically based pest management in outdoor urban environments. This research sought to determine whether the addition of wildflower plantings would enhance the occurrence, abundance and impact of beneficial arthropods in the landscape, and to determine the potential compatibility of pest-resistant turfgrass and natural control of Japanese beetle, Popillia japonica Newman, and fall armyworm, Spodoptera frugiperda (J.E. Smith). A bermudagrass cultivar (susceptible to fall armyworm), a zoysiagrass cultivar (resistant to fall armyworm), and two different commercially available wildflower mixes all harbored a diverse array of beneficial arthropods in both large and small plot evaluations. A wildflower mix containing 15 species of flowers provided significant, season-long increases in foliar-dwelling spiders and bigeyed bugs during 1-yr of a 2-yr study in large (1,512 m2) plots. Ground-dwelling spiders were more...

Insecticide Dips for Control of Japanese Beetle and Other Soil-Infesting White Grubs in B&amp;B Nursery Stock

Abstract Studies conducted in 1996, 1998 and 1999 show that immersion of root balls in Dursban® (chlorpyrifos) significantly reduces the number of white grubs, particularly Japanese beetle, Popillia japonica Newman, in B&amp;B (ball and burlap) nursery stock. In 1996, the influence of root ball size, soil type, and dip time on the efficacy of Dursban® 50WP, Dursban® 4E, and Oftanol® 2F (isofenphos) for white grub control in dipped B&amp;B nursery stock was evaluated. The grubs found within the root balls were primarily oriental beetle, Exomala orientalis (Waterhouse), European chafer, Rhizotrogus majalis (Razoumowsky), Asiatic garden beetle, Maladera castanea (Arrow), northern masked chafer, Cyclocephala borealis Arrow and Japanese beetle. With one exception, all the insecticide treatments caused similar grub mortality (96–100%) in 61.0 and 81.3 cm (24 and 32 in) root balls, respectively, and in sand or clay soil. There were no significant differences in grub survival due to dip time (1, 2, and 5 min). However, there were consistently fewer live grubs recovered from the root balls dipped 2 or 5 min compared with the number of live grubs recovered from root balls dipped for 1 min. In 1998, trees with 30.5, 45.7 and 61.0 cm (12, 18 and 24 in) root balls were dipped in either 0.453 or 0.906 kg ai/378.5 liter (1 or 2 lbs ai/100 gal) of Dursban® 4E for 2 mins. Both rates of Dursban® provided 100% control of Japanese beetle grubs in all three root ball sizes. Five trees from each treatment were planted one week after dipping and were evaluated for phytotoxicity up to 12 months after dipping. Most of the trees with 30.5 cm (12 in) root balls dipped in Dursban® died. Three of five trees with 45.7 (18 in) root balls dipped in the low rate of Dursban® and all five root balls dipped in the high rate had small leaves. One tree dipped in the low rate and 2 trees dipped in the high rate died 12 months after dipping. All of the trees with 61.0 cm (24 in) root balls dipped in the low rate of Dursban® survived and showed no signs of phytotoxicity. Trees with the same root ball size dipped in the high rate of Dursban® exhibited smaller leaves in 3 of the 5 trees. In 1999, trees with 61.0 cm (24 in) root balls were dipped in either 0.453, 0.226 or 0.113 kg ai/378.5 liter (1, 0.5 or 0.25 lbs ai/100 gal) of Dursban® 4E for 2 mins. All rates of Dursban® provided 100% control of Japanese beetle grubs.

Preventing White Grub Infestation in Container-Grown Nursery Stock

Abstract Preplant media incorporation of Talstar 0.2 G (bifenthrin) at 10 ppm (parts per million) or Fireban 1.5 G (tefluthrin) at 15 ppm, based on dry weight of the medium, provided complete control of Japanese beetle (Popillia japonica Newman), oriental beetle [Exomala orientalis (Waterhouse)], and European chafer [Rhizotrogus majalis (Razoumowsky)] in container nursery plants for two growing seasons. Talstar 0.67 F drenched immediately after planting also prevented establishment of these species in containers for two growing seasons. Marathon 1 G (imidacloprid) preplant media incorporated at 6–17.8 g (a.i.)/m3, provided incomplete control, while Marathon 60 W was completely effective when drenched in mid-summer prior to inoculating the pots with eggs. Other granular products mixed into potting media, including 10 ppm of fipronil or Mach 2, or 150 g (a.i.)/m3 of Lorsban or SuSCon Green, provided good control for one season. Several treatments prevented establishment of Japanese but not oriental beetle grubs. Curative drenches were generally ineffective. Registered treatments providing two years of control (Talstar at 10–25 ppm) can be used by growers to prevent white grub larval establishment in containers. Their usage should allow shipment of treated plants throughout the United States and Canada.

Control of Japanese Beetle and Masked Chafer Grubs with Halofenozide (RH-0345), 1995

Abstract This test was con ducted in turf-type tall fescue at the University of Kentucky Spindletop Farm, near Lexington. The turf was on a Maury silt loam soil (pH = 6.4) with negligible thatch. Plots (4X6 ft; 2 ft untreated borders) were arranged in a RCB, with 4 replications. The turf was treated on 27 Jul, during flight of JB. The soil population consisted mostly of eggs, with some 1st instars. Granular formulations were preweighed, mixed with dry sand, and applied by gloved hand. Liquid applications were applied at 50 gal/acre using a low volume, CO2 sprayer equipped with 4 Spraying System 8004 Tee Jet nozzles that delivered 2109 g pressure per cm2. Each plot was syringed with about 1/8 inch of water within 5 min after application, and the whole site received 3/4 inch irrigation as soon as the last treatment was applied. Conditions during application were 88°F with winds &amp;lt; 10 mph. There was 0.23 inch of rainfall on 26 Jul. the day before the test. There was no additional rain until 5 Aug, when 1.78 inch fell. Plots were sampled on 12 Sep by cutting a 3 X 1.5 foot strip, aboul 3 inches deep, from the center of each plot with a motorized sod cutter. Sod was rolled back, broken apart, and examined for grubs which were counted and identified.

Control of Japanese Beetle and Northern Masked Chafer Larvae on a Golf Course Rough in Summit County, OHIO, 1995

Abstract The study was located on a golf course rough at Akron, Ohio. Insecticides were applied 24 Aug to plots 8 X 10 ft (2.4 X 3.1 m) arranged in a RCB replicated 4 times. Granular materials were applied using a drop spreader. All liquids were applied with a CO2 sprayer and TeeJet™ 8015 nozzles at 60 psi (4.22 kg/cm2) pressure that delivered a volume of 3 gal/1000 ft2 (1222 liter/ha). The entire experimental area received ½inch of posttreatment irrigation using the golf course system. Environmental conditions at time of treatment were as follows: JB: approximately 12/ ft; 20% 1", 70% 2nd, 10% 3rd instars; NMC approximately 8/ft2; 20% 2nd, 80% 3rd instars; Turf: level, dry, 2.25 inch (5.7 cm) ht, 50% Kentucky bluegrass, 25% annual bluegrass, 25% bentgrass, No thatch; Soil: moist, 72°F at 1 inch (2.5 cm) and 72°F at 3 inch (7.6 cm); Weather: sunny, 75°F, 0-2 mph (0-3 km/h). Efficacy data taken 27 Sep (30 DAT) were based on the number of live, in six 7 X 7 inch (17.8 X 17.8 cm) square samples from each plot.

Chemical Evaluations for Control of Japanese Beetle on Grapes, 1995

Abstract In an experimental ‘Clinton’ vineyard at Wooster, Ohio, plots consisted of 2 grape vines, with 4 replications per treatment in a randomized block design. Treatments were applied as foliar sprays at a rate of 100 gpa (935 liter/ha) on 18 Jul. A hand-held CO2 sprayer operating at 45 psi (3.2 kg/cm2), equipped with a 9505-E-TeeJet nozzle, was used to apply treatments. No surfactant was added to any of the treatments. On 18 Jul, after treated foliage was dry, 5 grape leaves were removed from the outside canopy of each plot for use in the bioassay. Leaves were brought into the lab on 0, 1, 3, and 6 d after initial treatment and placed in round 1-gal. ice cream containers along with 10 Japanese beetles. The beetles used in these studies were collected in traps in an untreated area. The 1-gal containers were modified by placing plastic liners inside and cheesecloth over the open top. Beetles were confined in the cages with the treated foliage for 24 h after which the number of dead beetles was determined.

Influence of a Surfactant on the Efficacy of Registered Insecticides for Control of Japanese Beetle and Northern Masked Chafer Larvae on a Golf Course Rough in Summit County, OHIO, 1995

Abstract The study was located on a golf course rough at Valley View Golf Course in Akron, Ohio. Applications were made 23 Aug to plots 8 X 10 ft (2.4 X 3.1 m) arranged in a RCB, replicated 4 times. The formulations were tank mixed with various concentrations of an organosilicone surfactant (OSS). Tank mixes were applied with a CO2 sprayer and TeeJet™ 8015 nozzles at 60 psi (4.22 kg/cm2) pressure that delivered a volume of 3 gal/1000 ft2 (1222 liter/ha). After all treatments were applied the area was irrigated with approximately 3/8 inch (1 cm) of water using the golf course system. Environmental conditions at the time of treatment were as follows: White grubs: approximately 25/ft2, 60% NMC 3rd instars, 40% JB 2nd and 3rd instars; Turf: level, dew, 2 inch (5 cm) ht, 30% bentgrass, 30% crabgrass, 20% annual bluegrass, and 20% Kentucky Bluegrass, 1/8 inch thatch; Soil: moist, 78°F at 1 inch (2.5 cm) and 80°F at 3 inch (7.6 cm); Weather: clear, 76°F, 0 -3 mph wind. Efficacy data taken 27 Sep (35 DAT) were based on the number of live larvae in six samples 7X7 inch (17.8 X 17.8 cm) in from each plot. Analysis of variance was done on plot total transformed to log (X+l) and means separated by LSD test at P = 0.05.

Japanese Beetle Larval Control With Bifentrhin and B.T. Var. Japonica, 1995

Abstract Thirteen treatments were applied to a golf course fairway in Ossippee, NH for Japanese Beetle control, Plots were 7 X 7 ft, replicated 4 times, in a RCB design. Treatments were applied 15 Aug and rated 24 Sep. Granules were applied with a salt shaker and sprays with a CO2 boom sprayer, 8004 nozzles, at 40 PSI, in 2 gal water per 1000 ft2. Plots were rated by counting the number of live larvae in 2 ft2. Pretreatment density was 18.8 larvae per ft2. Larvae were 91% second and 9% third instar. Conditions at the time of treatment were: air temperature, 69.8°F; wind, 2 mph; sky, cloudy, light showers; soil temperature, 1 inch; 76.6°F; thatch depth, 0.5 inch; soil pH, 5.6; slope, 2%; soil texture, sandy loam; sand 58%, silt 23%, clay 19%; soil organic matter, 6.4%; soil moisture, 13.6%; post treatment precipitation, 0.2 inch immediately, irrigation every other day.

Influence of Application Time on the Efficacy of Insect Growth Regulators and Insecticides for Control of Japanese Beetle and Northern Masked Chafer Larvae on a Golf Course, 1994

Abstract The study was located on a golf course fairway at Atwood Resort, Delroy, OH. Insecticides were applied 11 Aug and 6 Sep to plots 4 × 10 ft (1.2 × 3.1 m) arranged in a RCB, replicated 3 times. Granular materials were applied with a shaker jar. Liquid treatments were applied with a CO2 sprayer with Teejet XR8010VS nozzles at 30 psi (2.19 kg/cm2) pressure that delivered a volume of 3.1 gal/1000 ft2 (1262 liter/ha). After all treatments were applied each treatment date, the area was irrigated approximately V* inch (6 mm) of water using the golf course system. Environmental conditions at the 11 Aug treatments were as follows. White grubs: 8-10/ft2, 100% NMC, 30% 1st and 70% 2nd 3rd instars present. Turf: &amp;lt; 5° slope, dry, 1-2 inches height (2.5-5 cm height), 40% bentgrass, 40% annual bluegrass, and 20% Kentucky bluegrass, no thatch. Soil: moist 75°F at 1 inch (2.5 cm) and 74°F at 3 inches (7.6 cm). Weather: cloudy and light rain, 67°F, 0 mph wind. Environmental conditions at the 6 Sep treatments were as follows. White grubs: 2nd and 3rd instars present, no pretreatment count or species identification. Turf: &amp;lt;5° slope, dry, 1-2 inches height (2.5-5 cm height), 40% bentgrass, 40% annual bluegrass, and 20% Kentucky bluegrass, no thatch. Soil: very moist, 65°F at 1 inch (2.5 cm) and 74°F at 3 inches (7.6 cm). Weather: sunny, 64°F, 0 mph wind. Efficacy data taken 27 Sep (47 &amp; 21 DAT) were based on the number of live larvae in five samples 7 × 7 inches (17.8 × 17.8 cm) from each plot. Analysis of variance was done on plot totals and means separated by LSD test.

Chemical Evaluations for Control of Japanese Beetle on Grapes, 1994

Abstract Treatments were evaluated for efficacy against the Japanese beetle in an experimental ‘Concord’ vineyard at Wooster, Ohio. Plots consisted of 2 grape vines, with 4 replications per treatment in a randomized block design. Treatments were applied as foliar sprays at a rate of 100 gal/acre (935 liters/ha) on 13 and 27 Jul. A hand-held COz sprayer operating at 45 psi (3.2 kg/cm2) and equipped with a 9505-E-TeeJet nozzle was used to apply treatments. No surfactant was added to any of the treatments. On 27 Jul, after treated foliage was dry, 5 grape leaves were removed from the outside canopy of each plot for use in the bioassay. Leaves were brought into the lab on 0, 1, 3, 6, and 8 days after initial treatment and placed in round 1-gal cardboard containers along with 10 Japanese beetles. The beetles used in these studies were collected in traps in an untreated area. The 1-gal containers were modified by placing plastic liners inside and cheese cloth over the open top. After allowing beetles to feed on treated foliage for 24 h, a count of the number of dead beetles was taken. The insect holding room was maintained at 75°F (23°C) with ca. 65% RH. No phytotoxicity was observed in these studies.

Soil Interactions with Chemical Insecticides and Nematodes Used for Control of Japanese Beetle (Coleoptera: Scarabaeidae) Larvae

Mortality of last-instar Japanese beetles, Popillia japonica Newman, was highest when exposed to isazophos, bendiocarb, and chlorpyrifos in 30-ml arenas containing California soils in laboratory assays. Carbaryl and two nematodes, Heterorhabditis bacteriophora Poinar and Steinernema glaseri (Steiner), were less effective treatments in these arenas. Soil × treatment (insecticides and nematodes) interactions were highly significant, often changing larvicide rank order of efficacy within soils. Soil characteristics identified by regression analysis as affecting insecticidal activity were organic matter (chlorpyrifos, bendiocarb, and S. glaseri ) and pH (carbaryl and isazophos). In arenas (7.6-cm diameter by 15 cm) simulating turf conditions, S. glaseri was the most effective treatment, followed by chlorpyrifos, then bendiocarb. The influence of irrigation on improving insecticide efficacy increased with higher soil organic matter. Because no treatment was completely effective against larvae, eradication of Japanese beetles cannot depend entirely on control tactics directed against the immature stages.