Pest Of Turfgrass Research Articles

POTENTIAL OF AZADIRACHTIN FOR MANAGING BLACK CUTWORMS AND JAPANESE BEETLE GRUBS IN TURF

Botanical insecticides have potential for managing insect pests with low hazard to humans and the environment. Azadirachtin, a limonoid extracted from the seeds of the neem tree, Azadirachta indica (Meliaceae), acts as an insect growth regulator and antifeedant against many crop pests. We evaluated two commercial azadirachtin formulations, Azatrol EC and Azatin XL (1.2 and 3.0%, respectively) against two important turfgrass pests: black cutworms [BCW], Agrotis ipsilon, and Japanese beetle [JB], Popillia japonica. Feeding on azadirachtin-sprayed creeping bentgrass caused molting disorders and death of early-instar BCW, and slowed feeding and stunted the growth of late instars. Azadirachtin also showed systemic activity against early instar BCW fed bentgrass treated via a root soak, and some deterrence of late instars in the field. Application to Kentucky bluegrass, followed by irrigation, killed 2nd-instar JB at 5 times label rate, but label rates did not provide control in the greenhouse or field. Azadirachtin residues in turf did not deter egglaying by JB. This work indicates that azadirachtin will suppress BCW if applied when early instars are present, but probably will not effectively control late instars or root-feeding grubs.

Endophyte–grass complexes and the relationship between feeding preference and performance in a grass herbivore

AbstractOverseeding non‐endophytic turfgrass lawns with endophytic turfgrass is considered promising for the development of integrated pest management programs in urban landscapes. In this context, a better understanding of the variability in the preference–performance response of insect herbivores exposed to endophytic grasses could be useful to develop efficient practices. Specifically, while endophytic varieties that are strongly toxic and avoided could provide good control of mobile pests, varieties that are toxic but not avoided could be more suitable for the control of sedentary pests. In this laboratory study, we investigated how the infection of 10 grass varieties by Neotyphodium endophytes affected the feeding performance and preference of newly hatched nymphs of the hairy chinch bug, Blissus leucopterus hirtus Montandon (Heteroptera: Lygaeidae), a common turfgrass pest in north‐eastern USA. We found that endophytes generally induced a strong relationship between feeding performance and preference in this herbivore. However, two endophytic varieties did not conform to this relationship, with one variety being highly toxic but not avoided and the other less toxic but highly avoided. These results provide a solid basis to further explore the impacts of endophytic grasses on the dispersal and survival of insect pests in mixed stands of endophytic and non‐endophytic plants.

Functional Response of the Tiger Beetle <I>Megacephala carolina carolina</I> (Coleoptera: Carabidae) on Twolined Spittlebug (Hemiptera: Cercopidae) and Fall Armyworm (Lepidoptera: Noctuidae)

The functional response of the tiger beetle Megacephala carolina carolina L. (Coleoptera: Carabidae) was determined on adult twolined spittlebug, Prosapia bicincta (Say) (Hemiptera: Cercopidae), and fourth instars of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), in single-prey and two-prey systems. In the laboratory, M. carolina carolina demonstrated a type II functional response for P. bicincta and S. frugiperda in both single- and two-prey systems. Search efficiency of M. carolina declined for both prey as the initial number of prey increased. Of the total prey consumed, M. carolina carolina killed significantly more S. frugiperda than P. bicincta in the single-prey system (8.0 and 4.5, respectively) and the two-prey system (5.0 and 2.0, respectively). Estimates of attack coefficient, a, were not significantly different for P. bicincta and S. frugiperda in the single-prey (0.07 and 0.02) and two-prey systems (0.04 and 0.06), respectively. The handling time, T(h), was significantly greater for P. bicincta (5.02 and 10.64 h) than for S. frugiperda (2.66 and 4.41 h) in single- and two-prey systems, respectively. Estimations of attack coefficient and handling time in the single-prey system were used to predict prey preference of M. carolina carolina. No strong prey switching response was observed. M. carolina carolina showed no preference for either prey. However, in the presence of S. frugiperda, the functional response of the predator for P. bicincta was reduced. M. carolina carolina is a potential predator of one or more turfgrass pests and should be considered in conservation efforts.

Susceptibility of Twolined Spittlebug (Hemiptera: Cercopidae) Life Stages to Entomophagous Arthropods in Turfgrass

Prosapia bicincta (Say) (Hemiptera: Cercopidae), the twolined spittlebug, is an economic pest of turfgrass in the southeastern United States. No data concerning natural enemies of P. bicincta in turfgrass have been reported previously. We compared predation of spittlebug eggs, nymphs, and adults in the laboratory by potential generalist predators commonly found in turfgrass: bigeyed bugs Geocoris uliginosus Say and Geocoris punctipes Say; red imported fire ant, Solenopsis invicta Buren; wolf spiders (Lycosa sp. Walckenaer); carabid beetles Harpalaus pensylvanicus DeGeer and Calosoma sayi Dejean; and tiger beetles Megacephala carolina carolina L. Eggs were readily consumed by generalist predators. S. invicta consumed 100% of the eggs offered. H. pensylvanicus and C. sayi were also significant predators of P. bicincta eggs. Nymphs live in spittlemasses that protect them from attack by predators, but exposed nymphs were susceptible to attack when mechanically removed from their spittlemasses. S. invicta and M. carolina carolina caused significant mortality of exposed nymphs. P. bicincta adults are aposematic and have the ability to reflex bleed; however, reflex bleeding did not prevent attack by predators. S. invicta and M. carolina carolina killed 100% of the adult spittlebugs offered in laboratory bioassays. Lycosa sp. are less voracious predators of adults. Sound background knowledge about P. bicincta and its potential natural enemy complex is important for the development and implementation of a detailed, site-specific, biologically based pest management program in turfgrass.

Susceptibility of Twolined Spittlebug (Hemiptera: Cercopidae) Life Stages to Entomophagous Arthropods in Turfgrass

Prosapia bicincta (Say) (Hemiptera: Cercopidae), the twolined spittlebug, is an economic pest of turfgrass in the southeastern United States. No data concerning natural enemies of P. bicincta in turfgrass have been reported previously. We compared predation of spittlebug eggs, nymphs, and adults in the laboratory by potential generalist predators commonly found in turfgrass: bigeyed bugs Geocoris uliginosus Say and Geocoris punctipes Say; red imported fire ant, Solenopsis invicta Buren; wolf spiders (Lycosa sp. Walckenaer); carabid beetles Harpalaus pensylvanicus DeGeer and Calosoma sayi Dejean; and tiger beetles Megacephala carolina carolina L. Eggs were readily consumed by generalist predators. S. invicta consumed 100% of the eggs offered. H. pensylvanicus and C. sayi were also significant predators of P. bicincta eggs. Nymphs live in spittlemasses that protect them from attack by predators, but exposed nymphs were susceptible to attack when mechanically removed from their spittlemasses. S. invicta and M. carolina carolina caused significant mortality of exposed nymphs. P. bicincta adults are aposematic and have the ability to reflex bleed; however, reflex bleeding did not prevent attack by predators. S. invicta and M. carolina carolina killed 100% of the adult spittlebugs offered in laboratory bioassays. Lycosa sp. are less voracious predators of adults. Sound background knowledge about P. bicincta and its potential natural enemy complex is important for the development and implementation of a detailed, site-specific, biologically based pest management program in turfgrass.

Prediction of Masked Chafer,Cyclocephala pasadenae, Capture in Light Traps Using a Degree-Day Model

In order to obtain information on the biology of the masked chafer Cyclocephala pasadenae (Coleoptera: Scarabaeidae), and to determine the date when 50% of the population is captured in light traps, field data were obtained during 4 years in Albuquerque, New Mexico. Capture of the 50% of the masked chafer population occurred approximately during the third week of July, of this one-generation per year insect. To reduce the need for intensive sampling and to obtain a predictable model for the capture of this pest, data were analyzed using trapezoidal numerical integration to estimate both a lower threshold and degree-days to predict the 50% capture date. A mathematical model based on field data accounted for the influence of natural environmental conditions on development, and predicted 50% capture dates within 1–4 days of what was actually observed from the field. The difference between predictions from field data is smaller than using estimates from laboratory-controlled experiments. The model presented here could serve as an accurate estimator of the appropriate timing to implement control measures of this important turfgrass pest.

Twolined Spittlebugs in Turfgrass

Revised! ENY-334, a 3-page illustrated fact sheet by E.A. Buss and L. Williams, describes the biology and behavior, detection, and control of this pest of centipedegrass and other turfgrasses and ornamentals in northern and northwestern Florida. This revision expands the section on chemical control and updates and restructures the tables of insecticides registered in Florida, separating those registered for homeowners from those registered for professional use. First published by the UF Department of Entomology and Nematology in October 1993, revised June 2006.

Oviposition Behavior of Pheropsophus aequinoctialis L. (Coleoptera: Carabidae): A Natural Enemy of Scapteriscus Mole Crickets (Orthoptera: Gryllotalpidae)

In the southeastern United States, South American Scapteriscus mole crickets are serious pests of turf and pasture grasses and vegetable seedlings. The larval stage of Pheropsophus aequinoctialis L. is a specialist predator of Scapteriscus mole cricket eggs and is currently under evaluation as a potential biological control agent. The objective of this study was to understand the oviposition behavior of P. aequinoctialis. The results indicated that in two-choice substrate oviposition arenas, female P. aequinoctialis significantly preferred to lay eggs in sand with mole cricket tunnels compared with artificially created tunnels or sand without tunnels. Physical tunnel presence influenced oviposition depth, but was not the only factor influencing oviposition. The reproductive strategy and behavior of P. aequinoctialis is discussed in relation to its specialized life history and to other carabid beetles displaying close host associations.

Efficacy of Botanical Insecticides from <I>Piper</I> Species (Piperaceae) Extracts For Control of European Chafer (Coleoptera: Scarabaeidae)

Biopesticides, including botanicals, can offer a safe and effective alternative to conventional insecticides for controlling major insect pests within an integrated pest management program. The current study highlights the practical application of a botanical insecticide for controlling a major insect pest of turfgrass: European chafer, Rhizotrogus majalis (Razoumowsky). Greenhouse and field trials were conducted to test the efficacy of a botanical formulation based on black pepper, Piper nigrum L. (Piperaceae), seed extracts to R. majalis larvae. The 7-d P. nigrum extract LC50 for R. majalis third instars was 2.5%. Successful treatment in the field was accomplished with the application of a 2% P. nigrum formulation to turfgrass infested with R. majalis second and third instars, whereas 4% extract was required in a second field trial with older third instars. The 2% pepper extract activity was comparable with the conventional insecticide diazinon in the first field trial. However, the 4% pepper extracts significantly affected the earthworm populations in treated plots compared with diazinon in the second field trail. The analysis of soil residues for piperamides in the P. nigrum extract determined a half-life of 1 - 2.6 d in the first and second field trials, respectively. This confirmed the expectation that under field conditions the residual activity would be less than conventional insecticides, thereby reducing the environmental risk associated with pesticide use. We recommend the pepper formulation for spot treatment applications when population densities reveal an epicenter of infestation rather than broadcasting over large areas, thus helping to minimize cost and negative affects on nontarget invertebrates.

A MODIFIED POOL DESIGN FOR COLLECTING ADULT MOLE CRICKETS (ORTHOPTERA: GRYLLOTALPIDAE)

A MODIFIED POOL DESIGN FOR COLLECTING ADULT MOLE CRICKETS (ORTHOPTERA: GRYLLOTALPIDAE)

Laboratory and field evaluation of Korean entomopathogenic nematode isolates against the oriental beetle Exomala orientalis (Coleoptera: Scarabaeidae).

The oriental beetle Exomala (Anomala) orientalis (Waterhouse) is an important pest of turfgrass in Korean golf courses, and although a few chemical insecticides are registered for insect pest control, they are not very effective against scarab larvae. There is also a growing concern in Korea about the run-off of insecticides into sensitive habitats and the potential for groundwater contamination. A safe and environmentally sound alternative is needed to conventional insecticides. We therefore evaluated six Korean entomopathogenic nematode isolates: S. carpocapsae Pocheon, S. glaseri Dongrae, S. glaseri Mungyeong, S. longicaudum Gongju, S. longicaudum Nonsan, and Heterorhabditis sp. Gyeongsan for their potential as bioinsecticides for control of E. orientalis. In addition, we evaluated a reduced chemical insecticide approach that combined chlorpyrifos-methyl with nematodes. In laboratory tests Heterorhabditis sp. Gyeongsan was the most efficacious, causing 100% mortality of the second and 38% of the third instars. All other nematode isolates caused 50-80% mortality of the second and 15-30% of the third instars. E. orientalis pupae were highly susceptible to all the Korean entomopathogenic nematode isolates except S. carpocapsae. In artificially infested field plots, all Korean nematode isolates cause 50-70% mortality of the third instar. A combination of a one-half rate of Heterorhabditis sp. and a one-half rate chlorpyrifos-methyl was synergistic, causing 91% mortality compared with 69% for the full rate of Heterorhabditis sp. or 22% for the full rate of chlorpyrifos-methyl. In a second field trial, a natural infestation of preoverwintering third instar was treated. In this trial a one-half rate of S. longicaudum Nonsan plus a one-half rate of chlorpyrifos-methyl caused 96.8% mortality, much more than a full rate of S. longicaudum Nonsan (45.9% mortality) or a full rate of chlorpyrifos-methyl (28.7% mortality). The interactions of Heterorhabditis sp. and S. longicaudum Nonsan with chlorpyrifos-methyl in our field trials appear to be synergistic.

The relative toxicities of insecticides to earthworms of the Pheretima group (Oligochaeta).

An artificial soil test was used to determine the LC50 values of carbaryl, chlorpyrifos, imidacloprid, cyfluthrin and fipronil against earthworms of the Pheretima group. For a 24-h interval, carbaryl was the most toxic to earthworms (LC50 = 77 mg kg-1), followed by imidacloprid (155 mg kg-1), cyfluthrin (351 mg kg-1), chlorpyrifos (390 mg kg-1) and fipronil (> 8550 mg kg-1) as the least toxic. For the 48-h and 7-day intervals, imidacloprid was the most toxic to earthworms (LC50 = 5 mg kg-1 and 3 mg kg-1 respectively), followed by carbaryl (16 mg kg-1; 9 mg kg-1), cyfluthrin (128 mg kg-1; 110 mg kg-1), chlorpyrifos (330 mg kg-1; 180 mg kg-1) and the least toxic was fipronil (> 8550 mg kg-1 both intervals). The surface application rates required to achieve these values are compared with the rates recommended for the control of turfgrass pests.

Life history and spatial distribution of Oriental beetle (Coleoptera: Scarabaeidae) in golf courses in Korea.

Larval and adult activity of the oriental beetle Exomala orientalis (Waterhouse), a pest of turfgrass in Korea, was investigated at four golf clubs in Pusan, Korea, from 1995 to 1999. Adult emergence was first observed on the greens in late May with peak activity occurring 2 wk later. During the day, E. orientalis adults were most active between 1800 and 2200 hours. First instars were found mostly in early July, second instars mostly in late July, and third instars from August to April. The density of larvae in fixed plots decreased steadily from the time of egg laying to pupation: 667/m3 on 26 July, 267/m3 on 29 August, and 122/m3 on 2 October 1997. All the observed E. orientalis completed one generation per year. Adult females were observed feeding on flowers of a late-blooming variety of Japanese chestnut (Castanea crenata Sieb & Zucc). E. orientalis larval densities were higher in greens with Japanese chestnut nearby, and where magpie, Pica pica sericea (Gould), feeding was observed. More E. orientalis adults emerged from the right, left, and back of greens than from the front or middle. The intensity of emergence was inversely proportional to the amount of golfer traffic on various parts of the green. Counting emergence holes may be a way that golf course superintendents can predict which greens and tees are most likely to be damaged from E. orientalis larvae without destructive sampling.

Use of Radiography and Tunnel Castings for Observing Mole Cricket (Orthoptera: Gryllotalpidae) Behavior in Soil

The behavior of mole crickets, serious pests of turfgrass, is poorly understood and has been rarely studied, predominantly because these insects dwell deep in the soil and are highly mobile. To better understand how the tawny mole cricket, Scapteriscus vicinus Scudder, and the southern mole cricket, S. borellii Giglio-Tos, behave in the soil, we used nondestructive x-ray techniques and wax and fiberglass resin castings to study the tunneling patterns and interactions of these mole crickets with their environment. Both species typically constructed Y-shaped tunnels to facilitate feeding and escape routes. Herbivorous tawny mole crickets tended to have more extensive and deeper tunnel systems than predatory southern mole crickets. Mole crickets maintained Y-shaped tunnels when subsoil density increased but often bent or terminated tunnels to avoid compacted areas. Both species maintained separate tunnels in the presence of other individuals of the same species. However, southern mole crickets exhibited more extreme separation, suggesting an avoidance behavior that may have been mediated by chemical, vibrational, or auditory cues. Although tawny mole crickets did not alter the shape of their Y-shaped tunnels in the presence of southern mole crickets, they sometimes would wall-off a tunnel, presumably in defense. Tawny mole crickets avoided contact with the entomopathogenic fungi, Beauveria bassiana (Balsamo) and Metarhizium anisopliae (Melchnikoff). This behavior suggests the potential of finding biologically active compounds that inhibit soil insect movement and could be used in the management of soil insect pests.

Insecticidal activity of Entomopathogenic fungus Nomuraea rileyi to lepidopteran pests of turfgrass

Insecticidal activity of Entomopathogenic fungus <I>Nomuraea rileyi</I> to lepidopteran pests of turfgrass

Evaluation of Turfgrasses for Resistance to Mole Crickets (Orthoptera: Gryllotalpidae)

Bermudagrass (Cynodon sp.) and paspalum (Paspalum vaginatum) genotypes were evaluated in laboratory, greenhouse, and field experiments for potential resistance to the common turfgrass pests, tawny mole cricket (Scapteriscus vicinus Scudder) and southern mole cricket (Scapteriscus borellii Giglio-tos). Potential resistance among 21 seashore paspalums to both insects in an environmental chamber at 27 °C, 85% relative humidity, and 15 hours light/9 hours dark) revealed that Glenn Oaks `Adalayd' was least tolerant of cricket injury, while 561-79, HI-1, and `Excalibur' were most tolerant. Nymphal survival was not influenced by turfgrass type. Plant selections that maintained the highest percentage of their normal growth after 4 weeks of feeding by tawny mole crickets over three separate greenhouse trials were 561-79, HI-1, HI-2, PI-509018, `Excalibur', SIPV-1 paspalums, and `Tifeagle' and `Tifsport' bermudagrasses. Although none of the tested genotypes was highly resistant to tawny mole cricket injury, `TifSport' bermudagrass and 561-79 (Argentine) seashore paspalum were most tolerant.

The toxicity of five insecticides to earthworms of the Pheretima group, using an artificial soil test

An artificial soil test was used to assess the toxicity of five insecticides, used for turfgrass pest management, to earthworms of the Pheretima group (Megascolecidae). The effects of cyfluthrin, carbaryl, chlorpyrifos, fipronil and imidacloprid on earthworm mortality, earthworm biomass and individual earthworm mass, were assessed. Carbaryl and chlorpyrifos had a significant greater effect on earthworm mortality than cyfluthrin, seven days after the application of the insecticides. No other significant earthworm mortality was found. None of the insecticides had a significant influence on earthworm biomass. Cyfluthrin initially reduced individual earthworm mass, but not biomass, more than the other insecticides. Carbaryl reduced biomass more than the other insecticides for all the assessments. Carbaryl, imidacloprid and cyfluthrin had a larger negative effect than the control, fipronil and chlorpyrifos on individual earthworm mass in the 14 and 21 day assessments. © 2000 Society of Chemical Industry

Assessing Irrigation Management for Its Effects on Disease and Weed Levels in Perennial Ryegrass

Irrigation management is generally assumed to have a significant effect on turfgrass pest management, yet little research has been done in this area. This field study was conducted on perennial ryegrass (Lolium perenne L.) maintained under golf course fairway conditions in 1995 and 1996. Objectives were to evaluate water savings afforded by monitoring turf ET and adjusting irrigation accordingly; to compare preventive and curative pesticide control measures for control efficacy and amounts required; and to evaluate effects of two irrigation regimes on turf quality, weed infestation, disease incidence, and pesticide requirements. Turf received either daily irrigation of 7.6 mm of water regardless of prevailing weather conditions or irrigation to replace approximately 80% of atmometer-estimated evapotranspiration (ET) on 3 d weekly. About 200% more water was applied to daffy irrigated turf than to turf irrigated based on atmometer-estimated ET. Similar amounts of active ingredient were used on both fungicide schedules in 1995. In 1996, a curative fungicide schedule resulted in application of 64% less active ingredient than a preventive schedule. Daily irrigation suppressed brown patch (Rhizoctonia solani Kühn) injury by 9% in 1995 and 2% in 1996 but resulted in more than twice as many dollar spot (Sclerotinia homoeocarpa F.T. Bennett) infection centers in 1996. Irrigation treatment had no effect on smooth crabgrass [Digitaria ischaemum (Schreb.) Muhl.] or dandelion (Taraxacum officihale Weber) incidence.

Effect of Endophyte Incidence in Perennial Ryegrass on Distribution, Host-Choice, and Performance of the Hairy Chinch Bug (Hemiptera: Lygaeidae)

Finding toxic, fungal endophyte-infected, grass cultivars that are not avoided by phytophagous insects could be an advantageous strategy when mixing Kentucky bluegrass, Poa pratensis L., and endophyte-infected grasses to control turfgrass pests. Field observations revealed that nymphs of the hairy chinch bug, Blissus leucopterus hirstus Montandon, are found mainly in thatch rather than on plants, regardless of time of day. We therefore developed laboratory bioassays incorporating thatch as a component of the hairy chinch bug habitat as a 1st step toward searching for advantageous grass-endophyte associations for chinch bug management in northeastern America. In nonchoice tests, a high incidence of endophyte ( Neotyphodium ) infection in tillers of the perennial ryegrass ‘Prelude II’, Lolium perenne L., induced high mortality of 3rd instars, whereas Prelude II with lower incidence of infected tillers or the Kentucky bluegrass ‘Merit’ were significantly more suitable. Incidence of infected plants affected nymph habitat selection, because all individuals in the presence of Prelude II with elevated percentage of infected tillers were found in thatch, whereas a significantly higher proportion of plants was colonized by nymphs confined with Prelude II with a lower incidence of endophyte infection or with Merit. In choice tests, Merit was strongly preferred over Prelude II, regardless of endophyte status of the ryegrass. Moreover, nymph mortality was not affected by the presence of endophyte-infected Prelude II when Merit was also available. These results suggest that highly mobile 3rd-instar hairy chinch bugs have the capacity to avoid toxic endophyte-infected grass cultivars. Such behavior could limit the value of mixing endophyteinfected grasses with Kentucky bluegrass for lawn protection, unless toxic cultivars that are not avoided by the hairy chinch bug can be found.

Seasonal Prevalence of Turf Grass Pest Catches in Synthetic Sex Pheromone Traps in Golf Courses in Saitama Prefecture

Seasonal Prevalence of Turf Grass Pest Catches in Synthetic Sex Pheromone Traps in Golf Courses in Saitama Prefecture