Bluegrass Billbug Research Articles

Bluegrass Billbug Feeding Response to Perennial Triticeae Grasses

In a 4-year field study, 25 perennial triticeae grasses, representing a wide range of genomes and genome combinations, were evaluated as potential hosts for the bluegrass billbug (Sphenophorus parvulus Gyllenhal [Coleoptera: Curculionidae]). Root-sample data suggested that Russian wildrye (Psathyrostachys juncea [Fischer] Nevski) was unsuitable for billbug reproduction. Numbers of immatures varied significantly among remaining entries. Rhizomatous entries were more tolerant of billbug injury than caespitose entries. Plant mortality rates were frequently 50% or higher for self-pollinated caespitose entries with the SH genome complement (Elymus spp.). Losses to billbugs among the remaining species, particularly those with the J, N, and P genomes, were insignificant. Billbugs did not discriminate between native and introduced grasses, as resistant and susceptible entries were identified in both groups. The results obtained here may aid in selecting triticeae grasses for reseeding in areas where billbugs have damaged stands in the past.

Spring Management of Bluegrass Billbug with Conventional and Experimental Formulations at the Valentine Research Center, University Park, PA, 1992

Abstract The field plot consisted primarily of Kentucky bluegrass. Treatment plots were 10 X 10 ft, arranged in a RCB design, replicated 4 times. Granular formulations were applied with a hand-held shaker and mixed with blank granules to facilitate product distribution. Liquid formulations were applied by using a COa sprayer with 4 8004 VS Teejet nozzles mounted on a 6 ft boom, operating at 28 psi, and delivering 5 gal/1000 ft2. At treatment time (20 May), the following soil and environmental conditions existed: air temperature, 70"F; soil temperature at 1 inch depth, 71.0°F; soil temperature at 2 inch depth, 64.0°F; RH 70%; amount of thatch, 0.25-0.5 inches; soil type, silt loam; soil particle size analysis: 22.5% sand, 61.5% silt, 16.0% clay; organic matter, 3.7%; soil moisture (oven baked), 21.5%; water pH, 7.0; soil pH, 6.6; and skies were clear. Immediately after treatment the experimental area was irrigated with 0.25 inches of water. Posttreatment counts were made 37 d later (26 Jun). Bluegrass billbug control was evaluated by removing four 0.087 ft2 sod samples from each replicate, and the total number of bluegrass billbug life stages (larvae, pupae, adults) were recorded from each sample and converted to a ft2 count. Sod samples were removed with a 4-inch cup cutter.

Curative Treatment with Conventional and Experimental Formulations to Control Billbug at the Valentine Research Center, University Park, Pennsylvania, 1991

Abstract The field plot consisted primarily of Kentucky bluegrass. Treatment plots were 9 X 6 ft, arranged in a randomized complete block design, replicated 3 times. Liquid formulations were applied in 2.0 gal water with a hand-held 2.5 gal sprinkling can. Granular formulations (G) were applied with a hand-held shaker and mixed with a fine grade top-dressing sand to facilitate product distribution. At treatment time (26 Jun), the following soil and environmental conditions existed: air temperature, 78°F; soil temperature at 1 inch depth, 78°F; RH, 58%; amount of thatch, 0.25-0.75 inch; soil type, silt loam; soil particle size analysis: 23.3% sand, 58.1% silt, 18.6% clay; organic matter, 2.9%; soil moisture (oven baked), 8.1%; water pH, 7.0; and soil pH, 6.2. Immediately after treatment the experimental area was irrigated with 0.25 inch of water. Posttreatment counts were made 14 d later (10 Jul). Bluegrass billbug control was evaluated by removing four 0.087 ft2 sod samples from each replicate. The total number of bluegrass billbug life stages (larvae, pupae, adults) were recorded from each sample and converted to a ft2 count. Sod samples were removed with a 4-inch cup cutter.

Preventive Treatment with Conventional and Experimental Formulations to Control Billbug at the Valentine Research Center, University Park, Pennsylvania, 1991

Abstract The field plot consisted primarily of Kentucky bluegrass. Treatment plots were 9 × 6 ft, arranged in a complete randomized block design, replicated 3 times. Liquid formulations were applied by using a C02 sprayer with four 8004VS Teejet nozzles mounted on a 6 ft boom, operating at 28 psi, and delivering 5 gal/1000 ft2. Granular formulations were applied with a hand-held shaker and mixed with a fine grade top-dressing sand to facilitate product distribution. At treatment time (10 May), the following soil and environmental conditions existed: air temperature, 78°F; soil temperature at 1 inch depth, 77°F; RH, 45%; amount of thatch, 0.25-0.75 inch; soil type, silt loam; soil particle size analysis: 20.3% sand, 60.1% silt, 19.6% clay; organic matter, 2.6%; soil moisture (oven baked), 22.6%; water pH, 7.0; and soil pH, 5.6. Immediately after treatment the experimental area was irrigated with 0.25 inch of water. Posttreatment counts were made 47 d later (26 Jun). Bluegrass billbug control was evaluated by removing four 0.087 ft2 sod samples from each replicate, and the total number of bluegrass billbug life stages (larvae, pupae, adults) were recorded from each sample and converted to a ft2 count. Sod samples were removed with a 4-inch cup cutter.

Biology, Distribution, and Taxonomy of Billbug Turf Pests (Coleoptera: Curculionidae)

The seasonal distributions and biology of four species of billbug on New Jersey turfs during 1986 and 1987 were examined; Sphenophorus parvulus Gyllenhal, a common pest of turfgrass, and three additional species, S. venatus s.l. (Say), S. minimus Hart, and S. inaequalis (Say), that had previously been overlooked as pests of cool-season turfgrasses in New Jersey. Linear pitfall trap collections of adults indicated: (1) a nearly equal overall abundance of the four species, (2) greater activity of S. inaequalis in the early spring and autumn, and (3) continued activity of S. venatus through the summer. The abundance of S. venatus adults throughout the summer, and continuous egg laying of all four species through August suggested a partial second generation. Larvae of all four species were found damaging cool-season turfgrasses during July. Laboratory-rearing work found little difference in the number of days for egg hatching and pupation, but a longer larval period for S. venatus . To facilitate identification and study by turfgrass specialists, an illustrated key to eight known billbug turf pests is provided and their geographic distributions in the United States are reviewed.

Additional Host Plants of Four Species of Billbug Found on New Jersey Turfgrasses

Studies were conducted on the host plants of four billbug species (Coleoptera:Curculionidae: Sphenophorus parvulus Gyllenhal, S. venatus Chitt., S. inaequalis Say, and S. minimus Hart) found on New Jersey turfgrasses. A collection of 4803 adults from pure stands of various turfgrasses revealed all four billbugs on Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and perennial ryegrass (Lolium perenne L.), and S. parvulus, S. venatus, and S. minimus on Chewings fescue (F. rubra L. ssp. commutata Gaud.). Since the presence of larvae, pupae, or teneral adults more accurately indicates the host status of a grass species, immature billbugs were collected from plugs of the various grass species and reared to adults for identification. All four species were reared from immature billbugs found in Kentucky bluegrass turf; immatures of S. venatus, S. inaequalis, and S. minimus were found in tall fescue; S. venatus and S. minimus in perennial ryegrass; and S. inaequalis in strong creeping red fescue (F. rubra L. ssp. rubra). A laboratory experiment was also conducted in which billbug adults were confined in petri dishes with either Kentucky bluegrass, perennial ryegrass, tall fescue, or bermudagrass (Cynodon dactylon Pers.). Only minor differences were found between the four grasses in billbug survival, number of eggs laid, and amount of feeding. In general, bermudagrass was the least favored host and the other grasses were equally adequate hosts. The results of this study indicate a need for updating host-plant lists of these four billbug species.

Effect of Acremonium Endophytes on Four Species of Billbug Found on New Jersey Turfgrasses

Laboratory studies were conducted to determine the effects of Acremonium endophytes on four species of billbug (Coleoptera:Curculionidae: Sphenophorus parvulus Gyllenhal, S. venatus (Say), S. inaequalis Say, and S. minimus Hart) found damaging cool-season turfgrasses in New Jersey. Billbug adults feeding on potted tall fescue (Festuca arundinacea Schreb.) plants infected with Acremonium coenophialum Morgan-Jones and Gams showed significantly greater mortality than billbugs feeding on endophyte-free tall fescue. Little difference was observed in amount of feeding. In petri dish preference tests, billbug adults were given a choice and, again, no significant difference was observed in the amount of feeding on endophyte-free versus endophyte-infected tall fescue tillers. In a third experiment, billbug adults were placed in petri dishes with either tall fescue with or without A. coenophialum or perennial ryegrass (Lolium perenne L.) with or without Acremonium lolii Latch, Christensen, and Samuels. Only small differences were seen in number of eggs laid and amount of feeding. Mortality of all four billbug species, however, was greater on both grasses when endophyte-infected.

Control of Bluegrass Billbug, 1988

Abstract The test was conducted on plots at University Park, Pa. The field plots consisted primarily of Kentucky bluegrass. Treatment plots were 9 x 6 ft, arranged in a randomized complete block design and replicated 3 times. Liquid and powder formulations were applied with a CO2 sprayer with 4 8004VS Teejet nozzles mounted on a 6-ft boom, operating at 28 psi and delivering spray at 5 gal/1,000 ft2. Granular formulations were applied with a hand-held shaker, and mixed with a fine grade of sand top dressing to facilitate product distribution. At treatment time (15 May) the following soil and environmental conditions existed: air temperature, 75°F; soil temperature at 1 inch depth, 66°F; RH, 60%; amount of thatch, 0.25-0.5 inches; soil type, loam; soil particle size analysis: 35% sand, 41% silt, 24% sand; soil moisture condition, moist; organic matter, 2.0%; water pH, 7.0; soil pH, 5.7; 5.4 inches of rainfall was recorded over the posttreatment period. Posttreatment counts were made at 62 DAT (18 July). Bluegrass billbug control was evaluated by removing 4 0,087-ft2 sod samples from each replicate, and total bluegrass billbug life stages (larvae, pupae, adults) were recorded from each sample and converted to a square-foot count. Sod samples were removed with a 4-inch cup cutter.

Spring Control of Bluegrass Billbug on Kentucky Bluegrass Plots At University Park, Pa., 1987

Abstract The field plots consisted primarily of Kentucky bluegrass. Treatment plots were 9 × 6 ft, arranged in a randomized complete block design and replicated 3 times. Liquid formulations were applied by using a CO2 sprayer with 4 8004VS TeeJet nozzles mounted on a 6-ft boom, operating at 28 psi and delivering 5 gal/1000 sq ft. Granular formulations were applied with a hand-held shaker, and mixed with a fine grade of sand top dressing to facilitate product distribution. At treatment time (6 May), the following soil and environmental conditions existed: air temperature, 70°F; soil temperature 68°F; RH 48%; amount of thatch, 0.25|0.7S| inches; soil type, sandy loam; soil size separation, 20.2% sand, 59.6% silt, 20.2% clay; soil moisture, 28.0%; soil pH 5.4; % organic matter, 4.7; water pH,' slightly acidic; 6.1 inches of rainfall was recorded over the posttreatment period. The experimental area was irrigated 18 h after treatment with 0.25 inches of water. Posttreatment counts were made 69 days later (7 Jul). Bluegrass billbug control was evaluated by removing 4 0.087-sq-ft sod samples from each; replicate, and the total bluegrass billbug life stages (larvae, pupae, adults) were recorded from each sample and converted to a sq-ft count. Sod samples were removed with 4-inch cup cutter.

Discriminant Analysis for Kentucky Bluegrass Billbug Resistance Ratings

Abstract Four categories of billbug (Sphenophorus parvulus Gyllenhal) resistance were identified and contrasted in terms of anatomical, morphological, and physiological characteristics of 12 Kentucky bluegrass (Poa pratensis L.) cultivars. Discriminant analysis was used as a separatory procedure to determine the relative importance of these plant characteristics to observed billbug resistance and to construct a prediction procedure for potential billbug resistance classes. Variables measured from field-, controlled environment-, and greenhouse-grown plants were analyzed for the most biologically revealing characteristics of potential billbug resistance. Separatory discrimination indicated that cultivars exhibiting moderate and high billbug resistance had tougher tissue than tolerant or susceptible cultivars. Tolerant and highly resistant cultivars differed from those susceptible and moderately resistant by concealing billbug injury. Development of a predictive classification procedure was promising, with percent correct classification ranging from 67% to 94%, depending on number and type of discriminating variables analyzed.

Seasonal History of Bluegrass Billhug, Sphenophorus parvulus (Coleoptera: Curculionidae), in a Range Grass Nursery

Field data on preimaginal survival of bluegrass billbug, Sphenophorus parvulus Gyllenhal, were collected weekly for three summers, 1982–84, from a hybrid wheatgrass, Elytrigia repens (L.) Nevski × Pseudoroegneria spicata (Pursh) Love, nursery near Kaysville, Utah. Population estimates were based on stem samples for early life stages and soil samples for later life stages. Locations of adult feeding and oviposition on host plants were the same. Seasonal populations were similar in all years except for a rapid decline of late instars in 1983. There was much overlapping of life stages, with early instars extending late into the season. Greatest mortality was during the egg stage (40–75%). Larval mortality was high (49–63%) for the root-feeding middle and late instars. Pupal mortality was low (0–16%)for all seasons. No predators, parasites, or pathological agents were found. Implications of bluegrass billbug successfully attacking an unnatural host, a rangeland wheatgrass, are discussed

Spring Control of Bluegrass Billbug on Kentucky Bluegrass Plots at University Park, Pa, 1986

Abstract Three insecticide treatments and one fertilizer treatment were applied 13 May for control of bluegrass billbug. The field plots consisted of Kentucky bluegrass (100%). Treatment plots were 6 x 15 ft, arranged in a RCB design and replicated 3 times. Liquid formulations were applied with a C02 sprayer with four 8504 Tee Jet nozzles mounted on a 6-ft boom, operating at 30 psi with a 5 gal/1,000 ft2 spray rate. The granular insecticide formulations were applied with a hand held shake-They were mixed with sand top-dressing to facilitate product distribution. The fertilizer treatment was applied with a 6-ft Scotts fertilizer spreader. At treatment time, the following soil and environmental conditions existed: air temp, 71°F; soil temp, 59°F; % RH, 61; amount of thatch, 0.5-1 inch; soil type, sandy-loam; % soil moisture, 9.4; soil pH, 5.7; % organic matter, 3.6. Posttreatment counts were made 65 days later (18 Jul). Bluegrass billbug control w is evaluated by removing four 0.087 ft2 sod samples from each replicate with a cup-cutter (4") and the total number of bluegrass billbug larvae were recorded from each sample and converted to a ft2 count.

Spring Control of Bluegrass Billbug on Kentucky Bluegrass Plots at University Park, Pa, 1986

Abstract Three insecticide treatments and 1 fertilizer treatment were applied 13 May for control of bluegrass billbug. The field plots consisted of Kentucky bluegrass (100%). Treatment plots were 6 X 15 ft, arranged in a RCB design and replicated 3 times. Liquid formulations were applied with a C02 sprayer with four 8504 Tee Jet nozzles mounted on a 6-ft boom, operating at 30 psi with a 5 gal/1,000 ft2 spray rate. The granular insecticide formulations were applied with a hand held shaker. They were mixed with sand top-dressing to facilitate product distribution. The fertilizer treatment was applied with a 6-ft Scotts fertilizer spreader. At treatment time, the following soil and environmental conditions existed: air temp, 71°F; soil temp, 59°F; % RH, 61; amount of thatch, 0.5-1 inch; soil type, sandy-loam; % soil mositure, 9.4; soil pH, 5.7; % organic matter, 3.6. Posttreatment counts were made 65 days later (18 Jul). Bluegrass billbug control was evaluated by removing four 0.087 ft2 sod samples from each replicte with a cup-cutter (4") and the total number of bluegrass billbug larvae were recorded from each sample and converted to a ft2 count.

Endophyte‐enhanced resistance in perennial ryegrass to the bluegrass billbug, Sphenophorus parvulus

AbstractEnhanced resistance in perennial ryegrass, Lolium perenne L., to the bluegrass billbug, Sphenophorus parvulus Gyllenhal is associated with the presence of a fungal endophyte, Acremonium loliae Latch et al. Severe billbug infestations occurred in 1981, 1983, and 1984 in two different turf evaluation field trials. Striking differences in cultivar response were observed. Subsequent investigations led to the discovery that billbug‐resistant ryegrass entries had very high levels of endophyte infection; whereas, susceptible entries had little or no endophyte infection. Further, the resistance was found to be maternally transmitted, and its dramatic prevalence within a maternal line was explained by the high frequency (over 95%) of seed transmission of the endophyte. This newly recognized source of plant resistance to several insect pests warrants additional study.RÉSUMÉAugmentation de la résistance de Lolium perenne à Sphenophorus parvulus due à la présence d'un champignon endophyte: Acremonium loliaeDes études récentes ont montré que la présence d'A. loliae à l'intérieur de L. perenne augmentait sa résistance à plusieurs insectes, dont Listronotus (Hyperodes) bonariensis et quelques pyrales — nous signalons ici que le même endophyte améliore aussi la résistance à Sphenophorus parvulus (Curculionidae).Des dégâts de S. parvulus ont été observés sur gazon en 1981, 1983 et 1984. Des différences marquées quant à la réaction des cultivars ont été notées; des études ultérieures ont montré que la résistance des cultivars était associée à des niveaux très élevés d'endophytes, ceux‐ci étant rares ou absents des cultivars sensibles. La transmission maternelle de la résistance à S. parvulus améliorée par la présence de l'endophyte qui avait été mise en évidence peut s'expliquer par le pourcentage élevé de graines transmettant le champignon. Les cultivars ‘Pennant’, ‘Premier’, ‘Regal’ aux niveaux élevés d'endophytes présentent peu de dégâts en gazon.Les avantages dûs à la présence de l'endophyte, exprimés par une meilleure résistance aux insectes, étaient particulièrement spectaculaires lorsque l'entretien de gazon était sommaire. L'amélioration due à l'endophyte n'apparaissait pas avec les gazons bien entretenus où il n'y avait pas de dégâts d'insectes. Ceci ne réduit en rien l'intérêt de cette forme de résistance aux insectes.Des questions importantes restent à résoudre: action de l'endophyte sur l'hôte, identification et influence des toxines éventuellement impliquées, examen d'autres plantes et insectes concernés.

Kentucky Bluegrass Cultivar and Blend Response to Bluegrass Billbug

Abstract A cultivar and blend trial of Kentucky bluegrass (Poa pratensis L.) demonstrated differential cultivar responses to larval infestation and injury by bluegrass billbug (Sphenophorus parvulus Gyllenhal). Correlation between billbug injury ratings and billbug larval density was r = 0.92. Injury ratings and larval density for blends approximated mean response for cultivars in pure stands. These results suggested that blending could be beneficial in reducing injury symptoms, if appropriate cultivars were selected.

Bluegrass Billbug (Coleoptera: Curculionidae) Tolerance of Ryegrass Cultivars and Selections1

We report for the first time that perennial ryegrass ( Lolium perenne L.) cultivars and selections, like those of Kentucky bluegrass ( Poa pratensis L.), show differential response to the bluegrass billbug ( Sphenophorus parvulus Gyllenhal). The correlation coefficient between injury rating and billbug density in soil and turf grass samples was r = 0.99. Of the 8 ryegrasses, 3 entries, ‘H 5-1352,’ ‘Pennant,’ and ‘Regal’ were found to be minimally damaged (1% to 4%), and the billbug density ranged from 0–0.5/0.09m2.

Further Host Range Studies on the Bluegrass Billbug, Sphenophorus parvulus Gyllenhal (Coleoptera: Curculionidae)1

During 1973 to 1975, 29 entries of 11 grass species and their cultivars which could be utilized as turf were examined for the presence of larvae of the bluegrass billbug, Sphenophorus parvulus Gyllenhal. Of all species examined, only Kentucky bluegrass, Poa pratensis L., showed significant infestations of S. parvulus larvae, with mean densities ranging from 3.05 to 14.45 larvae per 9.3 dm2 in 1974 and 1975. In 1975, the 13 Kentucky bluegrass cultivars used in the previous test were also utilized to determine possible associations between number of billbug larvae and number of live stems and thatch thicknesses per 9.3 dm2. Positive correlations existed between billbug larvae per 9.3 dm2 and number of live stems per 9.3 dm2 (r = 0.590; P < 0.01) and between billbug larvae per 9.3 dm2 and thatch thickness (r = 0.826; P < 0.01).

Sampling for Eggs, Larvae, and Adults of the Bluegrass Billbug1,2

A test was conducted to determine the precision of a pyrethrlns drench applied to the surface of Kentucky bluegrass, Poa pratenis (L.), to estimate the densities of soil and thatch inhabiting adult and root‐feeding larvae of the bluegrass billbug, Spenophorus parvulus Gyllenhal. Eighty‐seven percent of the adults were recovered from in situ sod with a 0.45 cm thick thatch while 82% of the adults were recovered from in situ sod with a 1.15 cm thick thatch. Root‐feeding larvae did not respond to the pyrethrins drench.In tests comparing a food blender extraction method with a hand dissection, method of extracting eggs and young larvae from infested plants, the number of eggs and larvae recovered from the blender extraction method did not differ significantly from the number of eggs and larvae recovered by hand dissecting the plant material.

Kentucky Bluegrass Cultivar Response to Bluegrass Billbug, Sphenophorus parvulus Gyllenhal1

Abstract A trial of 38 cultivare of Kentucky bluegrass (Poa pratensis L.) demonstrated genetic differences to an infestation of bluegrass billbug. The correlation coefficient between injury ratings and billbug larval density in sod samples was r = 0.73. Thatch accumulation was not significantly correlated (r = 0.31) with billbug density.

Differential Reaction of Kentucky Bluegrass Cultivars to the Bluegrass Billbug, Sphenophorus Parvulvs Gyllenhal1,2

Fifteen cultivars of Kentucky bluegrass, Poa pratensis L., were evaluated in the field for resistance to the bluegrass billbug, Sphenophorus parvulus Gyllenhal; none escaped infestation or damage. The correlation between infestation counts and damage index was significant at the 5% level (r=0.585). A range in resistance to billbug infestation and damage was recorded among the cultivars. ‘Nebraska common,’ ‘Park,’ and ‘South Dakota certified’ had the lowest number of billbugs/unit area.