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The annual bluegrass weevil (ABW) is a pest of fine turfgrass, but recent research has found that withholding insecticides for ABW control can reduce annual bluegrass cover. The objective of this research was to evaluate threshold-based insecticide and paclobutrazol programs for annual bluegrass control. The effect of three insecticide programs (preventive, threshold, and no insecticide) and four rates of paclobutrazol (0, 70, 105, or 210 g ha−1 applied monthly) were evaluated. Replicate experiments were conducted from April to November in both 2018 and 2019 on a mixed creeping bentgrass and annual bluegrass fairway in North Brunswick, NJ. By the conclusion of both experiments, all paclobutrazol programs exhibited reduced annual bluegrass cover compared with the nontreated plots. In threshold and no-insecticide programs, reduction in annual bluegrass cover was enhanced by paclobutrazol applied at 105 g ha−1 in both years, and at 70 g ha−1 in the 2019 experiment. Paclobutrazol at 210 g ha−1 resulted in annual bluegrass cover of −1 with the preventive insecticide program. A reduction in turfgrass quality from threshold-based insecticide programs persisted for a shorter duration than the no-insecticide program, regardless of paclobutrazol treatment. Threshold-based ABW insecticide programs that allow ABW feeding damage to occur can result in reduced annual bluegrass cover. These reductions were further enhanced by paclobutrazol applications. The combination of threshold-level insecticide with moderate rates of paclobutrazol (70 to 105 g ha−1) provided reductions in annual bluegrass cover that were similar to the highest rate of paclobutrazol (210 g ha−1) without ABW damage. Turfgrass managers who integrate the threshold-level insecticide approach and monthly paclobutrazol applications may achieve greater annual bluegrass control than either strategy alone if temporary reductions in turf quality can be tolerated.

The compatibility of microsclerotial granules of the entomopathogenic fungus Metarhizium brunneum (Petch) strain F52 with fungicides (chlorothalonil, iprodione, propiconazole, pyraclostrobin+metconazole, and propiconazole+trifloxystrobin) was determined. In vitro, chlorothalonil was not detrimental to conidial production and viability at all concentrations (1–1000 mg a.i. (active ingredient) l−1). Iprodione reduced conidial production at ≥ 100 mg a.i. l−1 but had no effect on viability. Propiconazole reduced conidial production at ≥ 10 mg a.i. l−1 and reduced viability at 1000 mg a.i. l−1. A pyraclostrobin+metconazole combination reduced conidial production at ≥ 10 mg a.i. l−1 and viability at ≥ 100 mg a.i. l−1. A propiconazole+trifloxystrobin combination reduced conidial production at all concentrations and viability at ≥ 100 mg a.i. l−1. In the greenhouse, propiconazole suppressed colony forming unit (CFU) counts at both low and high rates. Chlorothalonil and iprodione had no inhibitory effect on fungal growth. The number of CFUs recovered did not differ significantly ten, 20 or 30 days after treatment. This study provides baseline information for the potential commercial use of the microsclerotia in pest control.

The annual bluegrass weevil Listronotus maculicollis requires chilling exposure to terminate reproductive diapause during overwintering, but the effects of temperature on its post-diapause development in spring remain unclear. To explore this effect, overwintering adults were transferred from cold conditions (6°C/4°C, L:D 10:14) to different warm-up temperatures at L:D 12:12. When weevils were transferred to 7, 14 and 21°C in December and late January, the sizes of male and female reproductive organs were significantly smaller at 7°C than at 14 and 21°C. When weevils were transferred to 7, 9, 11, 13 and 15°C in late January, higher temperatures facilitated the post-diapause development. In both sexes, the sizes of reproductive organs and developmental rate increased with temperature. Reproductive organs did not grow significantly at 7°C in males and at 7–9°C in females, at which the percentage of developing weevils remained low. The time required for 50% of individuals to resume development was 44, 18, 13 and 8 days at 9, 11, 13 and 15°C, respectively, in males and 19, 14 and 8 days at 11, 13 and 15°C, respectively, in females. The threshold temperature for post-diapause development was 7.8°C in males, based on which 61.7 degree-days coincided with 50% of individuals developing. Under field conditions, the percentage of male and female maturity and insemination rate were low until early March, but all reached 100% by late March.

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.

Laboratory bioassays were conducted to evaluate the interactions between an entomopathogenic nematode (EPN), Steinernema carpocapsae (Nematoda: Steinernematidae), and the insecticide abamectin against the Potato tuber moth (PTM), Phthorimaea operculella, one of the key insect pests of potatoes (Solanum tuberosum). Steinernema carpocapsae was highly virulent against pre-pupae but significantly less virulent against pupae with respective LC50 values of 10.5 and 102.1 infective juvenile nematodes (IJs) per individual. Abamectin was similarly toxic to pre-pupae and pupae with respective LC50 values of 25.3 and 28.0 ppm. However, abamectin had detrimental effects on S. carpocapsae IJs causing up to 70% mortality when they were exposed at 1000 ppm for 24 h. PTM life stage had a strong effect on insect mortality when exposed to combinations of S. carpocapsae and abamectin. Against pre-pupae, combinations mostly had a synergistic effect on mortality with the exceptions being additive; against pupae, combinations mostly had an antagonistic effect on mortality with the exceptions being additive. The synergistic interaction in pre-pupae was the strongest and the antagonistic interaction in pupae the weakest when the combinations included the lowest abamectin rate (LC10) which can be explained by the more limited negative effect of the lower abamectin rate on the IJs. The synergistic interaction and the negative effect of higher abamectin rates on it were confirmed in a greenhouse experiment on potato plants. Combinations of abamectin and S. carpocapsae have potential for the control PTM and could help reduce to usage of synthetic insecticides in PTM management.

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.

Diapausing adults of the annual bluegrass weevil, Listronotus maculicollis, were collected from their hibernating sites at different times in autumn and winter, and subjected to different conditions to observe diapause termination by dissecting and measuring the reproductive organs. When diapausing weevils were maintained under laboratory cold conditions (10 h light at 6 °C:14 h dark at 4 °C) from early December to late March, the sizes of reproductive organs of both sexes increased or fluctuated slightly, and very few females had developing oocytes, suggesting that most adults did not resume development during the chilling period. When diapausing weevils (chilled for 40–83 days) were transferred to warm conditions (LD 14:10 and 21 °C) for different lengths of time, reproductive organ sizes in both sexes increased as chilling period prolonged, implying that chilling played an important role in diapause termination. Under field conditions, an apparent peak of reproductive development was observed on January 07 when 80% of males and 53% of females had resumed growth of reproductive organs. Diapausing weevils collected in September without chilling did not develop successfully despite exposure to warm conditions. In contrast, 87% of males and 93% of females collected from the field on January 21 had initiated reproductive development after 5 days of exposure to warm conditions, indicating the necessity of chilling for diapause termination. Male and female reproductive organ sizes increased faster and to a greater final size the longer the preceding chilling period was. The prolonged chilling period in the field resulted in more synchronized and advanced development in L. maculicollis when exposed to warm conditions.

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.

Recent work has shown the potential for enhanced efficacy of entomopathogenic nematodes (EPN) through their attraction to herbivore induced plant volatiles. However, there has been little investigation into the utilization of these attractants in systems other than in those in which they were identified. We compared (E)-β-caryophyllene and pregeijerene in the highbush blueberry (Vaccinium corymbosum) agroecosystem in their ability to enhance the attraction of EPN to and efficacy against the system's herbivore, oriental beetle (Anomala orientalis). The relative attractiveness of (E)-β-caryophyllene and pregeijerene to a local isolate of the EPN species Steinernema glaseri was tested in a six-arm olfactometer in the laboratory to gather baseline values of attraction to the chemicals alone in sand substrate before field tests. A similar arrangement was used in a V. corymbosum field by placing six cages with assigned treatments and insect larvae with and without compound into the soil around the base of 10 plants. The cages were removed after 72 h, and insect baits were retrieved and assessed for EPN infection. The lab results indicate that in sand alone (E)-β-caryophyllene is significantly more attractive than pregeijerene to the local S. glaseri isolate Conversely, there was no difference in attractiveness in the field study, but rather, native S. glaseri were more attracted to cages with G. mellonella larvae, no larvae, and cages with the blank control and G. mellonella larvae.

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.

Entomopathogenic nematodes have shown potential as biocontrol agents targeting larvae of the annual bluegrass weevil, Listronotus maculicollis Kirby, a major golf course turf pest in eastern North America with widespread insecticide resistance. Control levels of single applications of nematodes have been too low and variable in the past to support application by golf course managers for weevil control. We examined if splitting nematode applications in two at half rates approximately 1 week apart as well as combinations of the nematodes with the neonicotinoid imidacloprid could improve nematode performance. In greenhouse experiments in pots with grass infested with ABW larvae, the entomopathogenic nematodes Steinernema carpocapsae, S. feltiae, and Heterorhabditis bacteriophora were similarly effective for larval control. Combination with imidacloprid resulted in additive weevil mortality. In a field experiment with natural infestations of larvae using 1.25 and 2.5 × 109 nematodes ha−1, respectively, of S. carpocapsae and H. bacteriophora, additive mortality in the combinations with imidacloprid amounted to 82% and 79% control, respectively, at the high nematode rate. In three additional field experiments using only S. carpocapsae, the low and high nematode rate provided on average 59% and 74% control, respectively, while their combinations with imidacloprid provided 75% and 84% control, respectively. Imidacloprid alone averaged 37% control. Mortality in all combination treatments was additive. Splitting S. carpocapsae applications provided a marginal increase in mortality that was significant only in one of three experiments. However, combining split applications with imidacloprid provided 88–95% control which could offer an effective alternative to synthetic insecticides.

The annual bluegrass weevil (ABW), Listronotus maculicollis Kirby, is an economically important pest of short cut turfgrass. Annual bluegrass, Poa annua L., is the most preferred and suitable host for ABW oviposition, larval survival and development. We investigated the involvement of grass volatiles in ABW host plant preference under laboratory and field conditions. First, ovipositional and feeding preferences of ABW adults were studied in a sensory deprivation experiment. Clear evidence of involvement of olfaction in host recognition by ABW was demonstrated. Poa annua was preferred for oviposition over three bentgrasses, Agrostis spp., but weevils with blocked antennae did not exhibit significant preferences. ABW behavioral responses to volatiles emitted by Agrostis spp. and P. annua were examined in Y-tube olfactometer assays. Poa annua was attractive to ABW females and preferred to Agrostis spp. cultivars in Y-tube assays. Headspace volatiles emitted by P. annua and four cultivars of Agrostis stolonifera L. and two each of A. capillaris L. and A. canina L. were extracted, identified and compared. No P. annua specific volatiles were found, but Agrostis spp. tended to have larger quantities of terpenoids than P. annua. (Z)-3-hexenyl acetate, phenyl ethyl alcohol and their combination were the most attractive compounds to ABW females in laboratory Y-tube assays. The combination of these compounds as a trap bait in field experiments attracted adults during the spring migration, but was ineffective once the adults were on the short-mown turfgrass. Hence, their usefulness for monitoring weevil populations needs further investigation.

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.

We investigated the interactive effects of plant domestication and perennial cultivation on diversity and richness of plant-parasitic nematode (PPN) communities associated with highbush blueberry (Vaccinium corymbosum). Rhizospheric soil of V. corymbosum plants was sampled in coupled wild and cultivated sites within the Pinelands National Reserve. Although PPN diversity was higher in cultivated plant soil samples, richness was higher in wild plant soil samples. The most important soil properties, iron and calcium, were associated with cultivated soil and were the best predictors of genera abundance patterns. Nematodes in the genus Criconemoides were 187× more abundant in wild sites than cultivated and thus, were significant indicators of wild sites. In this study cultivation of V. corymbosum appears to benefit the PPN community but alters the community composition considerably.

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.

Rose sawfly, Arge ochropus (Gmelin), is one of the most important pests of ornamental plants such as roses and wild rose bushes in Northern Iran. We investigated the interactions between the insecticides imidacloprid and the entomopathogenic nematodes Heterorhabditis bacteriophora and Steinernema carpocapsae as control agents of fifth-instar larvae in the laboratory. The larvae were very susceptible to S. carpocapsae (LC50: 21 infective juvenile per larva) and H. bacteriophora (LC50: 32). Combinations of two imidacloprid rates (LC30 and LC50) and four rates of each nematode species (LC25–LC75) were tested. Combinations with the lower imidacloprid rate except for that with the highest H. bacteriophora rate caused higher mortality than both respective single-agent treatments. In combination with the higher imidacloprid rate, only one combination with H. bacteriophora and two combinations with S. carpocapsae caused higher mortality than both respective single-agent treatments. Interactions were generally str...

The annual bluegrass weevil (ABW), Listronotus maculicollis Kirby (Coleoptera: Curculionidae), is a serious and expanding pest of short-cut turfgrass on golf courses in eastern North America. Increasing problems with the development of insecticide resistance in this pest highlights the need for more sustainable management approaches. Plant resistance is one of the most promising alternative strategies. Bentgrasses are the dominant grass species on golf course fairways, tees, and putting greens in the areas affected by ABW. But Poa annua L. (Poaceae), a highly invasive weed, often constitutes a large percentage of turf stands in short-mown golf courses and is thought to be particularly susceptible to ABW. We studied resistance to ABW in four cultivars of creeping bentgrass, Agrostis stolonifera L., and two cultivars each of colonial bentgrass, Agrostis capillaris L., and velvet bentgrass, Agrostis canina L. (Poaceae), in comparison with P. annua by addressing the three major components of resistance: antixenosis (adult ovipositional and feeding preferences), antibiosis (larval survival and growth), and grass tolerance (grass damage). Our findings suggest that antixenosis/non-preference is at least partially involved in bentgrass resistance to ABW. Even though oviposition was observed in all tested grasses, females laid significantly fewer eggs in Agrostis spp. than in P. annua. Compared to P. annua, Agrostis spp. were also less suitable for larval development with lower numbers of ABW immatures recovered and larvae weighing less and being less advanced in development. Resistance levels to ABW larvae varied significantly among Agrostis spp. and cultivars. Agrostis canina was least preferred by females for oviposition and A. stolonifera was the least suitable for larval survival and development. Agrostis spp., especially A. stolonifera, were more tolerant to ABW feeding than P. annua. Our findings suggest that reduction in P. annua and replacement with Agrostis spp., especially A. stolonifera, wherever feasible should be integral to more sustainable approaches to ABW management.

Liming materials, calcium carbonate versus calcium magnesium silicate, were compared for effects on native white grub (Coleoptera: Scarabaeidae) populations in a New Jersey lawn. A silt loam soil near Princeton, N.J., of mixed cool-season turf with an initial pH of 5.0 received applications of either liming material in January 2007 for a target pH of 6.5. Control plots received no lime application. Grub numbers were reduced by more than 50% in plots amended with either calcium magnesium silicate or calcium carbonate when compared with the controls. Both calcium magnesium silicate and calcium carbonate were similarly effective in achieving this benefit.

The annual bluegrass weevil, Listronotus maculicollis Kirby, is a major insect pest of golf course turf in eastern North America. The weevil has been primarily managed with insecticides with applications targeting adults or the first through third instar larvae. It is not understood how effective larvicides are when significant numbers of fourth or even fifths instars are present. In greenhouse and field experiments we exposed larval populations of the weevil to the insecticides cyantraniliprole, spinosad, indoxacarb, and trichlorfon when the larval instar average was 2.5, 3.2, and 4.0, respectively (henceforth called L2.5, L3.2, and L4.0 timing, respectively). Greenhouse and field experiments showed similar trends in insecticide effectiveness. At the L2.5 timing, cyantraniliprole was the most effective and trichlorfon the least effective insecticide. At the L3.2 timing, all insecticides provide similar control levels. At the L4.0 timing, spinosad was more effective than the rest. Consequently, spinosad efficacy did not differ between application timings, cyantraniliprole and indoxacarb were more effective at the L2.5 and L3.2 than at the L4.0 timing, and trichlorfon was more effective at the L3.2 than the L2.5 and L4.0 timings. Our observations show that these insecticides remain effective until the larval instar average is approximately 3.2, giving applicators more time to accurately determine the need for insecticide applications which can lead to reduced insecticide use and thereby alleviate pressure for resistance development.

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.

Use of microbial control agents (MCAs) in turfgrass is very limited due to high turf quality standards and competition from synthetic insecticides. The entomopathogenic fungi Metarhizium spp. and Beauveria bassiana are available for the control of surface feeding insects (but little efficacy data is available) and white grubs (performance is variable and often unsatisfactory). The use of scarab-active Bacillus thuringiensis strains has been limited by significant differences in performance against different important white grub species. Paenibacillus popilliae use against Japanese beetle larvae is limited by availability and inconsistent performance. In New Zealand, Serratia entomophila is used commercially against Costelytra zealandica in pastures. Entomopathogenic nematodes (EPNs) have shown good control of caterpillars, billbugs, mole crickets, and many white grub species. However, poor shelf life and poor ease-of-use impinge on the wider use of EPN products. The use of MCAs could be increased by more systematically exploiting their ability to recycle and provide long-term pest suppression. Significant increases in MCA use will likely happen only through education and legislation.

The annual bluegrass weevil (ABW), Listronotus maculicollis Kirby, is an economically important pest of short-cut turfgrass in Eastern North America. Wide spread insecticide resistance warrants the development of alternative management strategies for this pest. ABW damage typically occurs in areas with a high percentage of annual bluegrass, Poa annua L., the preferred ABW host. Damage to bentgrasses, Agrostis spp., is much rarer and usually less severe. To aid the implementation of host plant resistance as an alternative ABW management strategy we investigated the tolerance of three bentgrass species to ABW feeding. Responses of P. annua, creeping bentgrass, Agrostis stolonifera L., colonial bentgrass, Agrostis capillaris L., and velvet bentgrass, Agrostis canina L., to adult and larval feeding were compared in greenhouse experiments. Grass responses were measured as visual damage, dry weight of the grass stems and leaves, color, density and overall grass quality. To determine possible mechanisms of grass tolerance constitutive fiber and silicon content were also determined. The three bentgrass species tolerated 2–3 times higher numbers of ABW adults and larvae than P. annua before displaying any significant quality decrease. Creeping bentgrass had the lowest damage ratings. ABW infestation caused higher plant yield reduction in P. annua (up to 42%) than in bentgrasses. Observed differences among the grass species in fiber and silicon content in the plant tissue are unlikely to play a role in the resistance of bentgrasses to ABW. Our findings clearly show that A. stolonifera is the best grass species for the implementation of host plant resistance in ABW management.

We tested the effect of host density on entomopathogenic nematode efficacy in 1-L pots with grass and soil. In four experiments, combinations ranged from somewhat resistant hosts (oriental beetle, Anomala orientalis, or northern masked chafer, Cyclocephala borealis, with Heterorhabditis bacteriophora) over more susceptible hosts (Japanese beetle, Popillia japonica, with Steinernema glaseri) to a highly susceptible host (P. japonica and S. scarabaei). In each experiment, four larval densities were exposed to two nematode rates over a 14-day period. A significant effect of host density on nematode efficacy occurred only in the A. orientalis–H. bacteriophora combination, but there was no clear trend in the data. This suggests that an exhaustion of available nematode populations to less lethal levels by high host numbers was counteracted by other factors such as increased chances for nematode-host contact and increased host susceptibility due to stress via reduced food resources and increased aggress...

Field experiments were conducted in turf maintained under golf course fairway conditions in May, June, and August 2009 and in August and September 2010 to evaluate the ability of entomopathogenic nematodes to control larval populations of the black cutworm, Agrotis ipsilon, on golf courses. Commercial products containing the entomopathogenic nematodes Heterorhabditis bacteriophora, Steinernema carpocapsae, S. feltiae, and S. riobrave were applied at 1.0 or 2.5×109 infective juveniles per ha against fourth-instar black cutworms. Larval mortality and turf damage were evaluated at 4 and/or 7 days after treatment (DAT). Steinernema carpocapsae was the best performing species due to a combination of high control rates (average 83%), most consistent results (70–90% range), high speed of kill (average 68% at 4 DAT), and prevention of significant turf damage despite very high larval densities at 0 DAT. Efficacy of S. feltiae and H. bacteriophora was often similar to that of S. carpocapsae but overall less consist...

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.

The ability of entomopathogenic nematodes to suppress larval populations of the annual bluegrass weevil, Listronotus maculicollis, was investigated under field conditions over a 3-year period (2006–2008). Combination of nematode species, application rate and timing produced strong numerical yet few statistically significant reductions. Steinernema carpocapsae Weiser, S. feltiae Filipjev, and Heterorhabditis bacteriophora Poinar applied at 2.5×109 IJs/ha reduced first generation late instars between 69 and 94% in at least one field trial. Steinernema feltiae provided a high level of control (94%) to low densities (~20 larvae per 0.09 m2), but gave inadequate control for higher densities (24 and 50% suppression). No significant differences were found among treatment timings. However, applications timed to coincide with the peak of larvae entering the soil (fourth instars) generally performed better than applications made prior to (preemptive) or after the majority of the population advanced from th...

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 ...

The entomopathogenic nematode, Steinernema scarabaei , is adapted to scarab larvae as hosts and has already shown exceptional potential for inundative control of these pests. To determine the long-term effects of S. scarabaei application on scarab populations and the nematode’s persistence, S. scarabaei was applied in mid-September at rates from 0.06 to 2.5 × 10 9 infective juveniles (IJs)/ha to turfgrass plots seeded with oriental beetle, Anomala orientalis , larvae. Scarab and nematode populations were monitored for 3–4 years thereafter. S. scarabaei provided excellent A. orientalis control (77–100%) within 1 month of application at rates of 0.25–2.5 × 10 9 (IJs)/ha and particularly in the following spring at rates of 0.1–2.5 × 10 9 (IJs)/ha (86–100%). S. scarabaei provided significant control in the next A. orientalis generation in two out of 10 treatments in fall (i.e., 13 months after application) and six out of 10 treatments in the following spring. Thereafter, significant control was only observed occasionally. S. scarabaei numbers were highly variable, and few significant differences among treatments were observed. S. scarabaei recovery from the treated plots was generally more consistent through the first spring after application and became more variable thereafter, but S. scarabaei was recovered for up to 4 years in the experimental plots. Endemic populations of Heterorhabditis bacteriophora and Steinernema carpocapsae , regularly recovered from the experimental plots and often in higher numbers than S. scarabaei , had no significant effect on A. orientalis densities but were able to coexist with S. scarabaei . Our observations suggest that, once current problems with its mass production can be overcome, S. scarabaei could be augmented periodically in areas with recurrent scarab infestations to provide long-term suppression.

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.

To better understand the differences in the efficacy of entomopathogenic nematode species against white grub species, we are studying the various steps of the infection process of entomopathogenic nematodes into different white grub species using nematode species/strains with particular promise as white grub control agents. In this study we compared the attraction of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), Steinernema glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and Heterorhabditis bacteriophora (GPS11 strain) to third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis, and late-instar greater wax moth, Galleria mellonella, larvae. Individual larvae were confined at the bottom of 5.5 cm vertical sand columns, nematodes added to the sand surface after 24 h, and nematodes extracted after another 24 h. Nematode attraction to hosts was strongly affected by nematode species but the effect of insect species varied with nematode species. S. glaseri had a high innate dispersal rate (i.e., in absence of insects) and was strongly attracted to insects without significant differences among insect species. S. scarabaei had a very low innate dispersal rate so that even a strong relative response to insects resulted in low absolute dispersal rates toward insects. S. scarabaei tended to be most attracted to G. mellonella and least attracted to C. borealis. H. zealandica had a high innate dispersal rate but only responded weakly to insects without significant differences among species. H. bacteriophora had limited innate dispersal and only weakly responded to insects with G. mellonella tending to be the most attractive and C. borealis the least attractive insect. It has to be noted that we cannot exclude that the use of different rearing hosts (A. orientalis and P. japonica larvae for S. scarabaei, G. mellonella larvae for the other nematodes) might have had an impact on the nematodes dispersal and relative attraction behavior. This study indicates that host attractiveness and nematode dispersal rates may contribute but do not play a major role in the variability in white grub susceptibility and/or nematode virulence.

The annual bluegrass weevil, Listronotus maculicollis, is a highly destructive pest of golf course turfgrass in the northeastern United States. We assessed the virulence of entomopathogenic nematodes to larvae and adults of L. maculicollis as an initial step in developing a biological control program for this pest. Two endemic and five commercially available nematode species were tested in soil and field infested turf core assays. Adult susceptibility was generally low to moderate (11–65% mortality) and was not affected by the age or overwintering condition of the insect. A mixture of two nematode species with different foraging behaviors (Steinernema carpocapsae and Heterorhabditis bacteriophora) achieved the highest levels of adult control, but required 6 days to obtain 50% mortality at five times standard field application rate (125 nematodes/cm2). Conversely, fourth- and fifth-instar larvae were highly susceptible to nematodes. Steinernema feltiae, S. carpocapsae, and S. kraussei significantly reduced fourth instars in both years of the study. The same three species along with the commercial strain of H. bacteriophora significantly reduced high densities of fifth instars to below field damage thresholds. In general, Steinernema spp. trended towards greater control than Heterorhabditis spp. for both fourth and fifth instars. No difference was observed among the virulence of endemic and commercial nematode strains to any L. maculicollis stage tested. The data indicate that Steinernema spp. could provide high levels of control when applied curatively against L. maculicollis larvae.

Combinations of the anthranilic diamide, chlorantraniliprole, and the entomopathogenic nematode Heterorhabditis bacteriophora were tested for control of third-instar white grubs in turfgrass. In greenhouse experiments, the combinations had a synergistic or additive effect on the oriental beetle, Anomala (= Exomala ) orientalis mortality, whether chlorantraniliprole was applied 1 week before H. bacteriophora or simultaneously. Combinations caused mortality to occur more rapidly than for the single agents. H. bacteriophora -chlorantraniliprole combinations had a synergistic effect on mortality of Japanese beetle, Popillia japonica , and northern masked chafer, Cyclocephala borealis , larvae in greenhouse experiments. Synergistic and additive effects on larval mortality were also observed in field experiments with A. orientalis and P. japonica . Across all experiments, synergistic interactions (based on a χ 2 test) were observed in 64% of the combinations. Significant control (based on ANOVA) was observed in 12% of the chlorantraniliprole alone treatments and 29% of the H. bacteriophora alone treatments, but significant control occurred in 76% of the combination treatments. H. bacteriophora progeny production per dead larva recovered in greenhouse experiments did not differ between H. bacteriophora alone and the combination treatments. Nematode densities were higher at 28 days after treatment in soil from the combination treatments due to the higher number of larvae succumbing to nematode infection. H. bacteriophora and chlorantraniliprole were compatible in tank mixes. Agitation in solution with up to 900 ppm chlorantraniliprole did not affect survival, infectivity, and reproduction of H. bacteriophora . H. bacteriophora -chlorantraniliprole combinations offer a safe and highly IPM compatible alternative for remedial white grub control.

BACKGROUND: An investigation was carried out to determine whether new neonicotinoid–nematode combinations and earlier applications against younger larval stages could increase the efficacy of synergistic neonicotinoid–entomopathogenic nematode combinations against white grubs. RESULTS: In the laboratory, combinations of the neonicotinoids imidacloprid and clothianidin and the nematodes Heterorhabditis bacteriophora Poinar and H. zealandica Poinar against third instars were compared. In Anomala orientalis (Waterhouse) and Popillia japonica Newman, H. bacteriophora–imidacloprid combinations showed the most consistent synergism but did not cause significantly higher mortality than H. zealandica–imidacloprid combinations. In Cyclocephala borealis Arrow, there was no clear trend as to which combinations caused the most consistent synergism, but H. zealandica–imidacloprid combinations tended to cause the highest mortalities. In the laboratory, imidacloprid–H. bacteriophora combinations provided more consistent synergism against third-instar than against second-instar A. orientalis, but mortality was higher in second instars. In field experiments, imidacloprid–H. bacteriophora combinations against A. orientalis and P. japonica provided more consistent synergism when applied in mid-September but more consistent control when applied in late August. CONCLUSIONS: Imidacloprid is a better synergist for entomopathogenic nematodes than clothianidin. Imidacloprid–nematode combinations are more effective against second instars than against third instars, allowing rate reductions of both agents to make this approach more competitive with full-rate applications of neonicotinoid alone. Copyright © 2008 Society of Chemical Industry

A series of laboratory and greenhouse experiments evaluated the entomopatho- genic nematodes Steinernema scarabaei Stock & Koppenhofer, Heterorhabditis bacteriophora Poinar, and H. zealandica Poinar for control of second- and third- instar cranberry white grub, Phyllophaga georgiana Horn (Coleoptera: Scara- baeidae), in cranberries. Steinernema scarabaei was the most effective species with 76� 100% control at a rate of 2.5 � 10 9 IJ/ha in the greenhouse experiments. H. zealandica and especially H. bacteriophora were generally less effective and required rates of 5� 10 9 IJ/ha for acceptable control. Larval stage had no effect on H. zealandica and H. bacteriophora performance, whereas S. scarabaei was more effective against third instars than second instars in the laboratory but not in the greenhouse experiments. Steinernema scarabaei, should it become commercially available, could be an effective alternative to chemical insecticides for P. georgiana management.

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