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The emphasis of this review is on the use and potential of entomopathogenic nematodes (EPNs) as biological control agents in sustainable food production across a wide range of agricultural and other commodities. To aid with the understanding of the potential of EPNs in sustainable food production, this review also provides overviews on EPN biology and ecology, mass production and application technology, and interactions with other management tools. First discovered in the 1920s, their commercialization as biopesticides in the 1980s was accompanied and followed by an exponential growth in research on their application, biology, and ecology, followed by a further expansion in more basic research areas since the mid-2000s. This review summarizes significant progress made in the research and application of EPN in insect pest management in important food crops including orchards, small fruit, maize, vegetables, tuber crops, greenhouses, and mushrooms. Significant factors affecting the success of EPN commercialization are also discussed. A growing interest in alternatives to synthetic insecticides and in organic agriculture opens opportunities for EPNs, but EPNs will need to be further improved with respect to efficacy, reduced costs, and ease of use. Moreover, their potential to recycle in host populations beckons to be further exploited for long term pest suppression.

The annual bluegrass weevil, Listronotus maculicollis (Kirby) (Coleoptera: Curculionidae), is the most difficult to control insect pest on golf courses in eastern North America. Insecticide resistance, particularly to pyrethroids, is a serious and expanding issue in its management. Optimal diagnostic tools for resistance detection are crucial for efficient resistance monitoring and mitigation. Developed vial and Petri dish assays clearly separated different resistance levels among weevil populations. With the pyrethroid bifenthrin, susceptible, moderately resistant (resistance ratios, RR50s 12.2-95.7), and highly resistant (RR50s 258.2-1760.9) populations were distinguished. With the organophosphate chlorpyrifos, susceptible, tolerant (RR50s 2.4-6.7), and resistant (RR50s 8.8-120.7) populations were distinguished. In validation assays, several bifenthrin and chlorpyrifos concentrations were needed to separate resistance levels in Petri dish (bifenthrin: 112.2 and 336.3 or 3,362.5 mg AI/m2; chlorpyrifos: 3.4 and 33.6 mg AI/m2) and vial (bifenthrin: 112.1 or 1,120.8 mg AI/m2; chlorpyrifos: 2.2 and 11.2 mg AI/m2) assays. The Petri dish assay with formulated bifenthrin and chlorpyrifos was the best option for L. maculicollis resistance detection and monitoring. It demonstrated sufficient discriminating power, accurately reflected resistance levels, and was easier to conduct. A single diagnostic concentration sufficed to separate susceptible and resistant populations. To determine different resistance or tolerance levels, two to three concentrations were necessary.

The annual bluegrass weevil, Listronotus maculicollis Kirby (Coleoptera: Curculionidae), is a major pest of golf course turf in eastern North America with widespread insecticide resistance. This study examined the effect of pyrethroid-resistance level on the efficacy of adulticides and larvicides from different insecticide classes commonly used for L. maculicollis management through greenhouse and field studies. The tested populations had previously been determined to be susceptible, moderately resistant, resistant, and highly resistant to the pyrethroid bifenthrin. Targeting adults, efficacy was significantly reduced for bifenthrin against the highly resistant population and for the spinosyn spinosad and the oxadizine indoxacarb against the resistant and highly resistant populations. Efficacy of the organophosphate chlorpyrifos was not significantly reduced. No adulticide provided significant control of resistant and highly resistant populations. Targeting larvae, the efficacy of spinosad and the anthranilic diamide cyantraniliprole was marginally reduced against the highly resistant population. Significant reductions in efficacy and no significant control were observed for indoxacarb against the highly resistant population and for the neonicotinoid clothianidin, the anthranilic diamide chlorantraniliprole, and the organophosphate trichlorfon against the resistant and highly resistant populations. Our findings lay the groundwork for management recommendations for populations with different resistance levels. Generally, synthetic insecticide applications should be minimized with greater use of larvicides supplemented with nonchemical control alternatives. The remaining effective larvicides should be rotated using cyantraniliprole, spinosad, and indoxacarb against resistant and cyantraniliprole and spinosad against highly resistant populations.

In 2014, the Japanese beetle Popillia japonica (Coleoptera: Scarabaeidae) was first spotted in northern Italy in the Nature Park of the Ticino Valley, its first detection in continental Europe. This polyphagous invasive species has the potential to cause serious losses to horticulture and agriculture. Particularly for its management in a Nature Park, environmentally friendly strategies are necessary. To develop baseline data for a biological control approach to the Italian outbreak of P. japonica, we conducted laboratory and field experiments testing several indigenous and commercial strains of the entomopathogenic nematode (EPN) species Heterorhabditis bacteriophora and Steinernema carpocapsae against P. japonica larvae. In the laboratory, strains of H. bacteriophora caused greater mortality (ranging from 57% to 100%) than those of S. carpocapsae (3% to 77%). In micro-plot field tests carried out at three different times, the most virulent indigenous EPN strain, H. bacteriophora ItH-LU1, showed again the best results ranging from 44% to 93% against young larvae. Finally, in a large-plot field trial, the commercial H. bacteriophora product provided 46% larval mortality. This study shows that H. bacteriophora strains have good potential as biological control agents of larvae of the invasive P. japonica in northern Italy.

We investigated the interactive effect of plant domestication and perennial cultivation on abundance, diversity and virulence of entomopathogenic nematodes (EPN) associated with highbush blueberry (Vaccinium corymbosum). The rhizospheric soil of V. corymbosum plants was sampled in coupled wild and cultivated sites within the Pinelands National Reserve, New Jersey, USA from 2011 to 2013 at three points during each year. To isolate and assess abundance of EPN communities, soil samples were baited with wax moth larvae (Galleria mellonella). A subsample of EPNs isolated from the soil was identified using molecular barcoding. The virulence of three native isolates against oriental beetle, Anomala orientalis, larvae was assessed at multiple densities of nematodes per host. A cursory assessment of EPN diversity was based on variation in molecular barcodes because many sequences could not be identified in the genomic database GenBank. The variation among barcodes suggested that diversity was higher in rhizospheric soil associated with wild plants than that of cultivated fields. Steinernema glaseri was the only EPN species able to be identified using molecular methods and was the only species isolated from the six cultivated fields with EPN presence. An interaction of environment, sampling point, and year explained significant differences in EPN abundance in 2011 and 2012 when soil samples were assessed by plant. However, in 2013, soil was assessed by field rather than plant and our results show EPN abundance was higher in cultivated than in wild sites. Soil nutrients and characteristics were also assessed in 2013. A PCA analysis of soil characteristics linked higher plant nutrients to soil from cultivated fields and higher soil moisture, organic matter, boron and lower pH to wild plant-associated soil. In this study, cultivation of domesticated V. corymbosum increases the abundance of the more virulent EPN species against the presumed host, A. orientalis but appears to eliminate genetic variability from the EPN community.

For insects that develop on few hosts and/or have immobile immature stages, optimal oviposition theory suggests that females should seek high-quality hosts that maximize larval development and reduce competition from conspecifics. However, there is a growing amount of evidence that suggests female choice may often be at odds with their offspring's development. Listronotus maculicollis (Kirby) (Coleoptera: Curculionidae) is a serious pest of golf course turfgrass in eastern North America. The weevil develops on few hosts and demonstrates improved fitness traits when developing on Poa annua L. (Poaceae). However, previous population studies observed either weak or no correlations between the spatial dispersion of larval populations and P. annua in the field. In this study, populations on three golf course fairways were monitored over a 4-year period (2009–2012) to determine whether the lack of spatial associations between preferred hosts and immatures was a result of spatial scale or the density and distribution of conspecifics. Spatial Analysis by Distance IndicEs (SADIE) was used to characterize the spatial dispersion of populations of individual stages (larvae and pupae), P. annua, and turfgrass damage. Life stages were aggregated in each observation, independent of population density or the spatial dispersion of hosts. The distribution of consecutive and non-consecutive immature stages was found to be correlated in all years, suggesting that females do not avoid patches already occupied by conspecific eggs. Surprisingly, significant spatial associations were not found between larvae and P. annua when the host plant was relatively abundant. Hence, multiple mechanisms may drive L. maculicollis oviposition site-selection behavior, and a flexible strategy may allow the weevil to persist in areas where P. annua is not the dominant species. Future studies are required to determine what other factors (e.g., natural enemy-free space, egg or time limitations) influence oviposition behavior.

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a serious threat to tomato production in the world. Due to serious issues with insecticide resistance, there is a dire need for alternative control methods. Entomopathogenic nematodes (EPN) have potential for the biological control of T. absoluta. In the laboratory, we examined the effect of temperature, soil type, and exposure time on the efficacy of the EPN species Steinernema carpocapsae (Nematoda: Steinernematidae) and Heterorhabditis bacteriophora (Nematoda: Heterorhabditidae) against last-instar T. absoluta larvae. Both species caused high mortality in loamy sand (89%) and coco peat (93%) but not in sandy loam (17%). H. bacteriophora caused 92-96% mortality at 19, 25, and 31°C; S. carpocapsae caused 89-91% mortality at 25 and 31°C but only 76% at 19°C. Both species caused similar mortality levels after 65-min exposure; thereafter, mortality increased only with S. carpocapsae reaching high levels even at a low concentration. Both species infected larvae within leaf galleries. When applied to whole large tomato plants in the greenhouse, both species provided similar control levels (48-51%) at high pest densities. Both species could be incorporated as an effective alternative to synthetic insecticides into T. absoluta management programs in greenhouse tomato production.

The annual bluegrass weevil (ABW), Listronotus maculicollis Kirby (Coleoptera: Curculionidae), is the most damaging golf course insect pest in eastern North America. Heavy reliance on synthetic insecticides against this pest has led to widespread problems in controlling ABW with pyrethroid resistance already reported from populations in southern New England. This study evaluated the degree and scope of ABW resistance, determined existing cross-resistance patterns, and confirmed laboratory findings under greenhouse conditions. The susceptibility of 10 ABW populations to insecticides of different chemical classes was assessed in topical, feeding, and greenhouse assays. The level of susceptibility to pyrethroids varied significantly among populations (LD50s ranging 2.4-819.1 ng per insect for bifenthrin and 1.1-362.7 ng for λ-cyhalothrin in the topical assay). Three populations were relatively susceptible to pyrethroids, and seven populations had moderate to high resistance levels (RR50 for bifenthrin ranging 30.5-343.1). The toxicity of chlorpyrifos (RR50s ranging 3.3-15.3), spinosad (RR50s 2.4-7.7), clothianidin (RR50s 4.2-9.7), and indoxacarb (RR50s 2.8-9.7) was decreased for the pyrethroid-resistant populations. Toxicity data for bifenthrin and chlorpyrifos obtained under more realistic greenhouse conditions confirmed laboratory observations, indicating that the topical assay is an accurate method of detection and measurement of resistance level. The current study expanded the previously known geographic range of ABW pyrethroid resistance to include the New York metropolitan area, New Jersey, and eastern Pennsylvania and provided clear evidence of cross-resistance not only within the pyrethroid class but also to several other chemical classes.

The annual bluegrass weevil, Listronotus maculicollis (Kirby), is a major pest of golf course turf in eastern North America and has become particularly problematic owing to widespread development of insecticide resistance. As an alternative option to manage resistant adult L. maculicollis, we explored combinations of the pyrethroid insecticide bifenthrin with an emulsifiable oil formulation of the entomopathogenic fungus Beauveria bassiana strain GHA (Bb ES). Combinations synergistically enhanced mortality in both insecticide-susceptible and insecticide-resistant L. maculicollis adults in the laboratory when bifenthrin was used at LC50s for each population. To determine the component behind the synergism, technical spores of B. bassiana GHA and the emulsifiable oil carrier in the fungal formulation were tested separately or in combination with bifenthrin. In both separate and combined applications, the emulsifiable oil carrier was responsible for high mortality within 3 d after treatment and interacted synergistically with bifenthrin, whereas fungus-induced mortality started later. Strong synergism was also observed in three field experiments with a relatively resistant L. maculicollis population. Combinations of Bb ES and bifenthrin hold promise as an effective L. maculicollis management tool, particularly of pyrethroid-resistant populations.

The oriental beetle, Anomala orientalis (Waterhouse) (Col., Scarabaeidae), is the most important root-feeding pest of blueberries and turfgrass in New Jersey, USA. Previous studies showed that mating disruption is a feasible option for oriental beetle management; however, assessing its efficiency can be challenging, and little is known on its long-term effects. Accordingly, we conducted studies to investigate low-dose pheromone lures equivalent to oriental beetle females (i.e. female mimics) as easyto-use indicators of mating disruption success, determine the distance at which oriental beetle males respond to female-mimic lures and assess the long-term (3-year) effects of mating disruption on oriental beetle populations in entire blueberry fields. Our studies showed that rubber septa baited with 0.3 lg of the oriental beetle sex pheromone (Z)-7-tetradecen2-one attract similar numbers of males as compared with virgin females and can thus be used as a female mimic. The range of attraction of this lure was found to be also similar to virgin females and

Entomopathogenic nematodes (EPNs) are obligate pathogens known to naturally persist in many habitats. Because survival is a fundamental component of persistence, we investigated whether vertical movement and other avoidance behaviors (i.e., in-host survival and latent infection), previously speculated as viable survival mechanisms, are exhibited during the cooler months in a temperate turfgrass habitat. The vertical distribution of populations of two EPN species, Steinernema scarabaei Stock & Koppenhofer (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), and two important hosts of these EPN species, the white grub species Popillia japonica Newman and Anomala orientalis Waterhouse (both Coleoptera: Scarabaeidae), were regularly monitored in turf plots from October through April in two consecutive years. Entomopathogenic nematode vertical distribution showed limited changes for H. bacteriophora but none for S. scarabaei. Recovery of H. bacteriophora showed a strong and consistent decline at 0–4 cm depth in the 1st year and a weaker decline at 4–10 cm in the 1st year and at 0–4 cm in the 2nd year. Due to high variability in the data, it was not possible to determine whether the decline in the upper soil layers was due to downward migration or attrition of infective juvenile nematodes. The decline occurred mostly during the first half of the season before the soil froze to any significant extent. The vertical distribution of both white grub species changed with temperature during fall and spring, but not during winter. Overwintering infective juveniles were only recovered in the soil. There was no evidence for successful in-host survival or latent infection by the nematodes in endemic white grub populations.

Listronotus maculicollis Kirby is a highly destructive pest of low mown, cool-season turfgrasses in the northeastern United States and Canada. Behavioral and electrophysiological assays were conducted to identify compounds that may be useful in developing novel monitoring techniques. In Y-tube assays, males and females responded differently to volatiles from intact and clipped annual bluegrass (Poa annua L.). Females were signiÞcantly attracted to intact P. annua but repelled from clippings; males did not respond signiÞcantly to either treatment. Electroantennogram (EAG) re- cordings from both sexes showed a signiÞcant response to volatiles from both treatments. Gas chromatography mass spectrometry (GC-MS) identiÞed 12 volatile compounds from P. annua of which nine were common to both intact plants and clippings. On average, seven-fold higher quantities of volatiles were collected from clippings than from intact plants (24.3 versus 3.4 ng/g of tissue/h). Eight compounds were released in signiÞcantly greater quantities from clippings of which 50% were the n-C6 compounds hexanal, (E)-2-hexenal, and (Z)-3-hexenyl acetate, commonly referred to as "green leaf volatiles" (GLVs). Only octanal was emitted in greater amounts from intact plants than clippings. These nine compounds were tested individually against male and female antennae. Both sexes displayed greatest sensitivity to nonanal, octanal, and (E)-2-hexenal, but a signiÞcant doseÐ response relationship was observed with all compounds tested. These studies indicate that both sexes respond physiologically and that L. maculicollis females exhibit behavioral responses to host-plant volatiles. Future studies will need to assess the effects of individual compounds and component mixtures on L. maculicollis behavior in the Þeld.

We characterized the spatio-temporal distribution of emerging overwintered adult Listronotus maculicollis populations colonizing golf course fairways with Spatial Analyses by Distance IndicEs (SADIE) with the goal to better target management tactics and to test assumptions for weevil preference for annual bluegrass (Poa annua). Adults randomly colonized and moved throughout fairways. However, cumulative captures were significantly aggregated along fairway edges closest to overwintering sites demonstrating progressive movement through the edges. Spatial association analyses suggest that the spatial patterns of cumulative captures of adults rather than weekly patterns were strongly associated with larvae, indicating that the adults enter fairways from the edges and deposit eggs over the course of several weeks. We did not observe an effect of host species on the distribution of either adult or larval L. maculicollis which leads us to question traditional assumptions of host preference for short mown P. annua. Instead, we propose that the aggregated distribution of larvae is generated by a low encounter rate of short mown hosts, rather than preference for species or cultivar. This study indicates that caution need to be applied when using preference-performance criteria in host preference studies. Future behavioural studies need to address the contributions of encounter rate and host species on L. maculicollis host selection and oviposition.

New legislation by governments and municipal authorities for the application of synthetic pesticides, including insecticides on turfgrass is currently changing the management of insect pests. Since the late 1990s, societal concerns over perceived health risks and environmental hazards of pesticides have led to tighter restrictions on insecticide use. In Canada, two provinces have banned the use of pesticides for cosmetic purposes and more than 152 municipalities have adopted some form of bylaw restricting or banning the use of landscape pesticides. Turfgrass managers are facing increasing constraints regarding the use of synthetic pesticides and only a few effective biological control agents are currently available on the markets to control turfgrass insects. Here we review the different pathogens that show potential for control and commercial use against turfgrass insect pests in North America. Even though numerous studies have shown the virulence of various pathogens against turfgrass insect pests, few ...

Entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) (EPNs) are generalist obligate pathogens present in the soil of most ecosystems. They have the potential to infect a broad host range, yet the potential for endemic EPNs to regulate soil-dwelling insect populations has received limited attention. We investigated the population dynamics of endemic EPNs to determine their ability to regulate annual bluegrass weevil ( Listronotus maculicollis ) (Coleoptera: Curculionidae) populations, a major pest of turfgrass in the northeastern United States. Weekly sampling of nematode and L. maculicollis populations was conducted in untreated fairway transects on three golf courses in New Jersey between April and October of 2006 and 2007. Steinernema carpocapsae and Heterorhabditis bacteriophora were found infecting all weevil stages from third instar to teneral adults. Both EPN species exhibited a distinct seasonality, appearing in high densities in the weeks immediately following high densities of first generation weevils in the soil. A positive temporal relationship was observed between densities of EPN-infected weevils and weevil stages between third instar and pupa, but L. maculicollis generational mortality due to EPN infection was highly variable between years and sites, ranging between 0 and 50%. Although infection densities and larval densities were positively correlated, per capita mortality did not increase with increased weevil densities. EPN distribution dynamically cycled between aggregated and uniform throughout the season across fairways. Few significant relationships were found to support the hypothesis that weevil spatial dispersion influences EPN spatial dispersion. The variability in EPN seasonal occurrence and generational impact on L. maculicollis together with the lack of spatial association with L. maculicollis suggest an inability of endemic EPN populations to reliably regulate weevil populations on golf course fairways.

Wax-based pelleted sex pheromone formulations were tested for efficacy in managing oriental beetle, Anomala orientalis Waterhouse, in turfgrass. Four pellet formulations were field tested at 25 g pheromone/ha during 2006 and 2007. Application patterns included pellets specifically placed in a uniform grid pattern and pellets scattered by a broadcast spreader. Treatment efficacy was measured by monitoring male A. orientalis captures in pheromone-baited traps, determining mating success of confined virgin females, and estimating subsequent densities of A. orientalis larvae in soil/sod samples. All formulation and application pattern combinations effectively suppressed mating for 2 wk after application as measured by reduction in male trap captures and mating success of confined virgins. Two formulations gradually lost efficacy beginning 2 wk after application and the two others after 3-4 wk. Application pattern had no effect on trap captures. The most effective formulation reduced trap captures by/=90% for 36 d, reduced mating success of confined females by 86-100% until 24 d after treatment, and reduced A. orientalis larval populations by 69%. In a previous study, sprayable formulations resulted in nuisance contamination of shoes that attracted male beetles outside of pheromone-treated areas. In contrast, shoes walked through pellet-treated areas did not attract male beetles. Pellet formulations have great potential for A. orientalis mating disruption, but more research is needed to optimize performance.

Masked chafers are scarab beetles in the genus Cyclocephala. Their larvae (white grubs) are below-ground pests of turfgrass, corn, and other agricultural crops. In some regions, such as the Midwestern United States, they are among the most important pest of turfgrass, building up in high densities and consuming roots below the soil/thatch interface. Five species are known to be important pests of turfgrass in North America, including northern masked chafer, Cyclocephala borealis Arrow; southern masked chafer, Cyclocephala lurida Bland [formerly Cyclocephala immaculata (Olivier)]; Cyclocephala pasadenae (Casey); Cyclocephala hirta LeConte; and Cyclocephala parallela Casey. Here we discuss their life history, ecology, and management. Published version

We tested the effect of soil moisture on the performance of four entomopathogenic nematodes species that have recently shown promise for the control of white grubs, i.e., Heterorhabditis bacteriophora, H. zealandica, Steinernema scarabaei, and S. glaseri. Experiments for all four nematodes were conducted in sandy loam, for S. scarabaei also in loamy sand and silt loam. Infectivity was tested by exposing third-instar Japanese beetle, Popillia japonica, to nematodes in laboratory experiments and determining nematode establishment in the larvae and larval mortality. Nematode infectivity was the highest at moderate soil moistures (−10 to −100 kPa), and tended to be lower in wet (−1 kPa) and moderately dry (−1000 kPa) soil. In dry soil (−3000 kPa), only S. scarabaei showed some activity. S. scarabaei was active from −1 to −3000 kPa in all soil types but the range of highest activity was wider in loamy sand (−1 to −1000 kPa) than in loamy sand and silt loam (−10 to −100 kPa). Persistence was determined in laboratory experiments by baiting nematode-inoculated soil with larvae of the greater wax moth, Galleria mellonella. For both Heterorhabditis spp. persistence was short at −10 kPa, improved slightly at −100 kPa, significantly at −1000 kPa, and was the highest at −3000 kPa. Both Steinernema spp. persisted very well at −10 kPa. However, S. glaseri persistence was the shortest at −10 kPa but did not differ significantly at −100 to −3000 kPa, whereas S. scarabaei persistence was not affected by soil moisture. Our observations concur with previous observations on the effect of soil moisture on entomopathogenic nematodes but also show that moisture ranges for infectivity and persistence vary among species. Differences among species may be based on differences in size and behavioral and physiological adaptations.

The feasibility of mating disruption in the oriental beetle, Anomala orientalis Waterhouse, with microencapsulated sprayable formulations of (Z)-7-tetradecen-2-one, the major sex pheromone component, was evaluated in turfgrass areas. The effect of the applications was measured by monitoring male A. orientalis captures in pheromone-baited traps throughout the flight period and estimating A. orientalis larval densities in September in soil/sod samples. Trap captures were 90–100% lower in the treated areas during the first 7–10 d after treatment, but started to increase thereafter. Therefore, applications were repeated after 14 d in most treatments. The formulation tested in 2002 and 2003 reduced trap captures by 87–88% with two applications of each 12.5 or 50 g pheromone/ha but only by 74% by a single application of 75 g pheromone/ha. Reductions of A. orientalis larval populations by 68–74% were not significant because of very high variability of larval densities in the nontreated areas. Two differ...

The efficacy of chemical and biological control agents against larvae of the Asiatic garden beetle, Maladera castanea (Arrow), in turfgrass under laboratory, greenhouse, and field conditions were determined. In field trials where insecticides were applied preventively against eggs and young larvae, the molt-accelerating compound halofenozide and the neonicotinoids imidacloprid and thiamethoxam were ineffective, whereas another neonicotinoid, clothianidin, provided 62–93% control. In greenhouse experiments against third instars in pots, the carbamate insecticide carbaryl was ineffective, whereas the organophosphate trichlorfon provided 71–83% control. In laboratory, greenhouse, and field experiments, the entomopathogenic nematode Heterorhabditis bacteriophora Poinar and Steinernema glaseri Steiner (not tested in the field) were ineffective against third instars, whereas S. scarabaei Stock & Koppenhofer provided excellent control. In microplot field experiments at a rate of 2.5 × 109 infective juveniles per ha, H. bacteriophora provided 12–33% control and S. scarabaei 71–86% control. Combinations of S. scarabaei and imidacloprid did not provide more control of third instars compared with S. scarabaei alone.

Previous observations on the effect of endophyte infection in turfgrass on white grub development and natural incidence have been variable and contradictory. We reexamined these white grub-endophyte interactions and expanded them to the previously not studied oriental beetle (Exomala [= Anomala] orientalis Waterhouse). Endophyte infection in strong creeping red fescue (Festuca rubra L. rubra) had no effect on survival and weight gain of neonate Japanese beetle (P. japonica Newman) and E. orientalis larvae in greenhouse pot experiments. In tall fescue (Festuca arundinacea Schreber) in greenhouse pot and in microplot field experiments, endophyte infection had no significant effect on survival and a weak negative effect on weight gain of P. japonica, but reduced E. orientalis survival without affecting its weight gain. In samples taken from tall fescue fields in October, the natural incidence of third instars was higher in endophytic than in nonendophytic turf in 3 of 4 yr. The effect was strongest ...

This study describes the basic ecological characteristics of the entomopathogenic nematode Steinernema scarabaei (Rhabditida: Steinernematidae) that was originally isolated from epizootics in scarab populations in New Jersey turfgrass areas. Under laboratory conditions, S. scarabaei infected a limited range of insect species and appeared best adapted to scarab larvae as hosts. It uses a widely ranging foraging strategy with a low attachment rate to mobile hosts on the soil surface but with excellent infection of sedentary host placed at >or=2 cm soil depth. It has a wide thermal activity range with optimum infectivity from 17.5 to 25 degrees C. Because of its foraging strategy and adaptation to scarab larvae as hosts, S. scarabaei has outstanding potential for the control of scarab pests.

We evaluated the effect of endophyte infection in the two turfgrasses tall fescue (Festuca arundinacea Schreber) and strong creeping red fescue (F. rubra L. ssp. rubra) on the susceptibility of three white grub species to the entomopathogenic nematode Heterorhabditis bacteriophora Poinar. Endophyte infection in strong creeping red fescue (only tested under greenhouse conditions) had no effect on nematode-susceptibility of third-instar oriental beetle (Exomala (=Anomala) orientalis Waterhouse) and northern masked chafer (Cyclocephala borealis Arrow). In tall fescue under greenhouse conditions, endophyte infection had a weak and variable enhancing effect on nematode-susceptibility of second- and third-instar E. orientalis and no effect on nematode susceptibility of third-instar C. borealis and Popillia japonica. However, under field conditions with natural white grub populations, endophyte infection in tall fescue had no significant effects on nematode efficacy against E. orientalis, P. japonica, and C. borealis. While it is possible that stronger interactions between endophytes and nematodes may occur with different grass species, cultivars, and endophyte strains, nematode-endophyte interactions appear to be too variable to allow predictions on nematode efficacy based on turfgrass endophyte status.

Several genera of grasses are capable of forming a mat of intertwined plants to form a solid ground cover with an extensive root mass. They can also regenerate from the crown after defoliation. The about 50 grass species amenable to use in turfgrass systems are further on able to form a high shoot density under the continuous mowing regimes characteristic for turfgrass systems (Christians, 1998). These properties allow turfgrasses to provide a hard–wearing permanent or semi–permanent ground cover that can be used for various recreational spaces in urban and suburban environments including lawns, parks, golf courses, and athletic fields. Other areas in which turfgrasses are grown include cemeteries, roadsides and sod farms. In the USA, turfgrass areas cover about 20 million ha and the size of the turfgrass industry is estimated at $40,000 million per year (National Turfgrass Federation, 2009). Besides their recreational uses, turfgrasses control soil erosion, capture and clean run–off water from urban areas, provide soil improvement and restoration, moderate temperature, reduce glare and noise, reduce pests, pollen and human disease exposure, create good wildlife habitats, and improve physical and mental health of urban populations (Beard & Green, 1994).

We tested biological control agents for the control of 3rd-instar scarab turfgrass pests, both for the masked chafer Cyclocephala hirta LeConte and the Japanese beetle, Popillia japonica Newman. The former species is endemic in California whereas the latter, although not yet established, constitutes a permanent serious threat to agriculture and horticulture in California. We conducted experiments using C. hirta in California and P. japonica in New Jersey. A field trial conducted in 2 different California turfgrass sites compared the field persistence in the absence of hosts of Bacillus thuringiensis Berliner subspecies japonensis Buibui strain, the milky disease bacterium, Paenibacillus (=Bacillus) popilliae (Dutky), and the entomopathogenic nematodes Steinernema kushidai Mamiya and Heterorhabditis bacteriophora Poinar to that of the organophosphate diazinon. Soil samples taken 0-70 d after applications were bio-assayed with P. japonica. Only diazinon and the entomopathogenic nematode S. kushidai caused substantial mortality and S. kushidai activity persisted significantly longer than diazinon activity. In greenhouse experiments, combinations of entomopathogenic nematode species usually resulted in additive mortality of scarab larvae. Combinations of S. kushidai and diazinon also resulted in additive mortality. In field trials, the efficacy of H. bacteriophora and especially S. kushidai and S. glaseri, was comparable to that of diazinon over 14-18 d. However, it is likely that at least S. kushidai would have outperformed diazinon over an extended period because of its longer persistence and potential for recycling in the hosts. S. kushidai, should it become commercially available, deserves further examination as an alternative to chemical white grub control especially as a highly compatible component of sustainable turfgrass management.

This study describes the basic ecological characteristics of the entomopathogenic nematode Steinernema monticolum that was originally isolated from soil in a mountain forest on Mount Jiri, Republic of Korea. Under laboratory conditions, S. monticolum infected a wide range of insect species but appeared best adapted to lepidopteran larvae as hosts. It uses an intermediate foraging strategy with a low attachment rate to mobile hosts on the soil surface and poor infection of sedentary hosts placed at  5 cm soil depth. S. monticolum infected hosts over a wide range of soil moisture ranging from ­ 1500 kPa to ­ 3 kPa. It has a wide thermal activity range with optimum infectivity from 12 to 25°C. When stored in water over a 6 month period, S. monticolum persisted well from 5 to 25°C. Its infectivity also remained high when stored from 5 to 15°C but declined faster at 25°C. Because of its foraging strategy and adaptation to cool temperatures, S. monticolum has potential for the control of pests, especially Lepidoptera, that hibernate in the upper soil layer or soil litter. Zusammenfassung – Ökologische Charakterisierung des entomopathogenen Nematoden Steinernema monticolum aus Korea – Die grundlegenden ökologischen Merkmale des entomopathogenen Nematoden Steinernema monticolum , einer Art, die ursprüglich aus dem Boden eines Bergwaldes am Jiri Berg in Korea isoliert worden ist, werden beschrieben. Unter Laborbedingungen infizierte S. monticolum einen weiten Bereich von Insektenarten, schien jedoch am besten an Larven von Lepidoptera angepasst zu sein. Dieser Nematode verfügt über ein intermediäres Wirtssuchverhalten mit einer niedrigen Anheftungsrate an bewegliche Wirte auf der Bodenoberfläche und einer niedrigen Infektionsrate von sedentären Wirten in  5 cm Bodentiefe. S. monticolum infizierte Wirte in einem weiten Bereich von Bodenfeuchtigkeiten (­ 1500 kPa bis ­ 3 kPa). Diese Art hat einen weiten thermischen Aktivitätsbereich mit optimaler Infektiösität von 12 bis 25°C. Bei Lagerung in Wasser über einen Zeitraum von sechs Monaten zeigte S. monticolum hohe Überlebensraten bei Temperaturen von 5 bis 25°C. Die Infektiösität blieb ebenfalls hoch im Bereich von 5 bis 15°C, nahm bei Lagerung bei 25°C aber schneller ab. Wegen seines Wirtssuchverhaltens und seiner Anpassung an kühle Temperaturen erscheint S. monticolum ein hohes Potentential für die Bekämpfung von Schadinsekten, inbesondere Lepidoptera, die in den oberen Bodenschichten oder im Streu überwintern, zu haben.

Many studies of entomopathogenic nematodes (Heterorhabditidae and Steinernematidae) have reported that only a small proportion (typically Steinernema: most dauers could be recovered in one sampling round when provided with sufficient suitable hosts. In contrast, Heterorhabditis bacteriophora frequently did not infect all available hosts, and infectious dauers were recovered in subsequent sampling rounds. This result is more consistent with the phased infectivity hypothesis, but further research is needed before we can be more confident in the hypothesis. For all species tested, the number of available hosts influenced population levels of nematode infectivity. This suggests that the infection status of hosts can influence whether a dauer infects. Our results indicate that phased infectivity is not a common phenomenon in entomopathogenic nematode dauers, despite the widespread acceptance of this hypothesis.

Combinations of the insecticide imidacloprid and entomopathogenic nematodes were tested for control of white grubs. In greenhouse tests, field-collected 3rd-instar white grubs were placed in pots with grass treated with imidacloprid, the entomopathogenic nematode Heterorhabditis bacteriophora (Poinar), or both. Combinations of imidacloprid and nematodes had a strong synergistic effect on mortality at imidacloprid concentrations ranging between 50 to 200 g (AI) / ha. This effect was observed when imidacloprid and the nematodes were applied at the same time or when imidacloprid was applied first followed by the nematodes 14 d later. The synergistic interaction occurred against a nematode-susceptible scarab species, Cyclocephala hirta LeConte, and against a more nematode-resistant scarab species, C. pasadenae Casey. When infective juveniles of H. bacteriophora were agitated in solutions of imidacloprid for 24 h, no negative effect on their survival and infectivity was observed.

Our objectives were to determine whether entomopathogenic nematode emergence from host cadavers is influenced by soil moisture, whether the nematodes can survive adverse desiccating conditions in the soil by remaining within the host cadaver, and whether differences in such an adaptation occur among species. In the first experiment, wax moth larvae killed by Steinernema glaseri, Steinernema carpocapsae, Steinernema riobravis , or Heterorhabditis bacteriophora were placed in soil water potentials ranging from −500 MPa (very dry) to −0.006 MPa (moist). No infective juveniles (Us) emerged from cadavers at −500 MPa, and only few S. glaseri and S. carpocapsae emerged at −40 MPa. Large numbers of IJs emerged at ≥ −5 MPa from cadavers containing S. carpocapsae, S. glaseri , or H. bacteriophora. S. riobrauis emerged only at ≥ −0.3 MPa. In the second experiment, cadavers were left in dry soil (−40 MPa) for various periods of time before being rehydrated. The number of Us emerging per cadaver and the infectivity of the emerged IJs were determined. IJ emergence declined with the time that the cadavers were left in dry soil. Regression analysis predicted that IJ emergence from cadavers with S. glaseri, S. carpocapsae, H. bacteriophora , or S. riobravis would stop after 27, 62, 80, and 111 days, respectively, in dry soil. We hypothesize that S. carpocapsae , a sit-and-wait forager, survives longer than S. glaseri because it is adapted to infect insects near the soil surface, whereas S. glaseri , an actively searching forager, is adapted to infect insects deeper in the soil profile. Cadavers colonized by S. carpocapsae , therefore, are more likely to be exposed to dehydrating conditions. H. bacteriophora , an actively searching forager, may survive longer within cadavers because the gummous consistency of its host cadavers retains moisture very efficiently. S. riobrauis may survive for considerable lengths of time within cadavers in adaptation to the subtropical, semiarid climate of its geographic area of origin.

Interactions between entomopathogenic nematode species with different foraging strategies were examined in the presence of two host species in soil. Based on differences in insect behavior and nematode pathogenicity, we hypothesized that black cutworm, Agrotis ipsilon (Hufnagel), larvae would be more likely to serve as hosts for Steinernema carpocapsae or Steinernema riobravis , whereas masked chafer grubs, Cyclocephala hirta LeConte, would be more likely to serve as hosts for Steinernema glaseri . In the laboratory, the highest mortality of and nematode penetration in A. ipsilon were observed for S. carpocapsae followed by S. riobravis and S. glaseri . In C. hirta , substantial mortality and nematode penetration were only observed for S. glaseri . After combined applications of two nematode species, S. carpocapsae dominated over S. glaseri in A. ipsilon , whereas S. glaseri and S. riobravis shared the host resources. In C. hirta , S. glaseri outcompeted each of the other species. In the greenhouse, containers with turfgrass were inoculated with S. glaseri , S. carpocapsae , or S. riobravis , or combinations of S. glaseri with either S. carpocapsae or S. riobravis . Four days later, each container received seven A. ipsilon and nine C. hirta larvae, and new insects were added at 30-day intervals. The densities of infective juvenile nematodes were monitored over 150 days by taking soil samples from each container. In the single species treatments, numbers of S. carpocapsae and S. riobravis increased after 30 days, decreased thereafter and remained low. Steinernema glaseri numbers fluctuated between low and high densities. In the combination of S. glaseri and S. carpocapsae , both species were depressed compared with the single species treatment. In the combination of S. glaseri and S. riobravis , both species coexisted and showed parallel fluctuations but S. glaseri dominated numerically. Our observations indicate that two entomopathogenic nematode species may successfully coexist in an area by having different foraging strategies that separate nematode species spatially, exhibiting host specificity, and occupying a different niche. In the field, patchy distribution and alternate hosts may also support nematode coexistence.

Laboratory and greenhouse studies were conducted to determine whether combining 2 entomopathogenic nematode species would result in synergistic, additive, or antagonistic effect against 2nd-stage larvae of the western spotted cucumber beetle, Diabrotica undecimpunctata undecimpunctata Mannerheim. After an initial screening of 12 nematode species/strains, the most efficacious Steinernema and Heterorhabditis and 2 Steinernema species that were intermediate in effectiveness were selected for further evaluations. In laboratory soil bioassays, tile lethal concentration resulting in 50% mortality (LC50) for the most virulent nematode, Steinernema carpocapsae (Weiser) All strain, was 14.5 infective juveniles followed by 18.4 infective juveniles for Heterorhabditis bacteriophora Poinar NCI strain, 48.1 infective juveniles for S. riobravis Cabanillas, Poinar and Raulston Texas strain, and 98.6 IJs for Steinernema sp. Hanrim strain. Combining 2 of the 4 nematode species at the LC25 values always resulted in an additive effect, regardless of the effectiveness of the individual nematode species. In the greenhouse, application of S. carpocapsae, S. riobravis, Steinernema sp., or H. bacteriophora was made alone or in paired combinations at the rates of 1 × 108 and 2.5 × 108 infective juveniles/ha against western spotted cucumber beetle larvae. At both rates, the most efficacious single nematode species against the larvae was S. carpocapsae . The combination of 2 nematode species showed variable results. Its efficacy ranged between as high as the better of the 2 combined species alone and as low as the less effective of the 2 species alone. In addition, the combined nematode treatments were always less effective than the most efficacious single nematode species, S. carpocapsae . We conclude that no advantage was gained by combining 2 entomopathogenic nematode species against western spotted cucumber beetle larvae.

The bionomics of Euborellia annulipes (Lucas 1847) were observed in Western Kenya. Exclusively 5 larval stages occurred and no winged or tegminate adults were recorded. FF laid up to 4 egg clutches with a total of 91.4 ± 11.8 eggs. In the laboratory, FF and MM lived 154 ± 7.1 days and 118.8 ± 6.3 days, respectively, and sex ratio was 1 :1.

Observations on the biology of Dactylosternum abdominale (Fabricius 1792) were made in W' Kenya in banana plantations. The 3 larval instars are polyphagous predators in decomposing plant tissues where pupation occurs. Development from egg to adult [Ig] takes 17-33 days. Ig [Ig] feed on the micro-fauna and -flora of decomposing plant tissues, on eggs and small larvae of insects and the plant tissues. Life-span is approximately 95 ± 2 days. The sex ratio is 1.16 in favour of the MM. FF lay on an average 1.7 egg cases per week, each containing 4 eggs. The pre-oviposition period is 16.6 days, post-oviposition period 3 days. At unnaturally high population densities fecundity declines. Decomposing plant tissue is more attractive to Ig than fresh plant tissues, and banana pseudostems more attractive than banana rhizomes. In poorly managed fields and during the rainy seasons population densities are higher due to the larger amount of decomposing plant tissue available. Observed population densities: 0.5-1.8 Ig/m 2 .

8 páginas, ilustraciones y tablas estadísticas., While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs). However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene) from citrus roots 9–12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus) compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis) again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests.

Binomial sequential sampling plans were developed to forecast weevil Listronotus maculicollis Kirby (Coleoptera: Curculionidae), larval damage to golf course turfgrass and aid in the development of integrated pest management programs for the weevil. Populations of emerging overwintered adults were sampled over a 2-yr period to determine the relationship between adult counts, larval density, and turfgrass damage. Larval density and composition of preferred host plants (Poa annua L.) significantly affected the expression of turfgrass damage. Multiple regression indicates that damage may occur in moderately mixed P. annua stands with as few as 10 larvae per 0.09 m2. However, > 150 larvae were required before damage became apparent in pure Agrostis stolonifera L. plots. Adult counts during peaks in emergence as well as cumulative counts across the emergence period were significantly correlated to future densities of larvae. Eight binomial sequential sampling plans based on two tally thresholds for classifying infestation (T = 1 and two adults) and four adult density thresholds (0.5, 0.85, 1.15, and 1.35 per 3.34 m2) were developed to forecast the likelihood of turfgrass damage by using adult counts during peak emergence. Resampling for validation of sample plans software was used to validate sampling plans with field-collected data sets. All sampling plans were found to deliver accurate classifications (correct decisions were made between 84.4 and 96.8%) in a practical timeframe (average sampling cost < 22.7 min).

Oriental beetle, Anomala orientalis Waterhouse (Coleoptera: Scarabaeidae), is a pest of turfgrass that may be controlled by applications of synthetic pheromone (Z)-/ (E)-7-tetradecen-2-one to disrupt mating. Laboratory experiments were conducted to determine release profiles of pheromone from experimental wax-based granules, a proprietary wax granule, and rubber septa commonly used in pheromone traps. Rubber septa loaded with 10, 100, and 300 microg per septum provided steady rates of pheromone release (zero-order) over 4 wk of laboratory evaluation (total = 1.1, 9.0, and 26.9 microg/4 wk, respectively). Septa with 1,000 microg per septum had a significant decline in the rate of pheromone release for this 4-wk exposure time (total = 119 microg/4 wk). A large proprietary wax granule (44 mg per granule, 25% wt:wt pheromone) provided a steady rate of pheromone release (total = 2,347 microg/4 wk per granule). Experimental granules (16 mg per granule) made of soywax with higher pheromone loads (10% wt:wt) approached zero-order release (steady state) (total = 69 microg/4 wk per granule), whereas smaller granules (4 mg per granule) with less pheromone (0.1% wt:wt) provided first-order release profiles (decreasing rate with longer exposure time) (total = 0.35 microg/4 wk per granule). A field trial in turfgrass demonstrated the potential of selected granular formulations to provide effective mating disruption for up to 4 wk, as measured by pheromone trap shutdown. Documenting pheromone release profiles for these experimental granules and rubber septa provides valuable information that will support future field evaluations of mating disruption as a control strategy.

We compared the penetration of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), S. glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and H. bacteriophora (GPS11 strain) into third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis. When larvae were exposed to nematodes for 6-72 h larval mortality and nematode establishment rate and occasionally speed of kill often showed the same pattern within nematode-white grub combinations. But no two nematodes or white grub species had the same pattern for these observations for all white grub or nematode species, respectively. Mortality, establishment, and speed of kill followed a similar pattern for H. zealandica, S. glaseri, and S. scarabaei, but there was no clear relationship for H. bacteriophora. Significant nematode establishment was only observed after at least 48 h exposure in most nematode-white grub combinations. Faster establishment was observed only for H. zealandica in A. orientalis and R. majalis (after 24 h) and for S. scarabaei in P. japonica and R. majalis (after 12 h). Nematode establishment after 72 h in the different scarab species was generally low for S. glaseri (

Entomopathogenic nematodes are used for inundative biological control of insect pests but also have potential for use in augmentative and/or inoculative biological control. Numerous new species are being described but generally, little information is provided on their ecology. Moreover, many species have been described previously without subsequent ecological information. This paper presents a number of simple experiments examining a nematode's physiological host range, host-foraging behavior, thermal activity range, and soil moisture activity range that provides the basic information necessary for further studies of a new species as a biological control agent. We suggest that any taxonomic description of new species should be combined with such an ecological study. This kind of information should also be generated for species in which no ecological studies have been done. In our study, we found that the entomopathogenic nematode Steinernema rarum which was described in 1986 infected a wide range of arthropod species under laboratory conditions but appeared to be best adapted to lepidopteran larvae as hosts. It used an intermediate foraging strategy infecting both mobile hosts on the soil surface and sedentary hosts below the soil surface efficiently. The range of soil moisture at which S. rarum was effective suggested an adaptation to the fluctuating soil moisture in the upper soil layers. Its temperature optimum of 25 degreesC corresponded well to the warm temperate climate of its area of origin in Argentina. The optimal storage temperature was around 15 degreesC. Our study suggests that S. rarum is well adapted to lepidopteran hosts with larvae spending part of their live on the soil surface and/or that pupate in the soil. Copyright 1999 Academic Press.