Overseeding Endophytic Perennial Ryegrass into Stands of Kentucky Bluegrass to Manage Bluegrass Billbug (Coleoptera: Curculionidae)

Abstract

Studies were conducted to determine the utility of overseeding endophyte enhanced varieties of perennial ryegrass, Lolium perenne L., into existing stands of Kentucky bluegrass, Poa pratensis L., to manage bluegrass billbug, Sphenophorus parvulus Gyllenhal, larval populations and their damage. Two commercial varieties of endophyte enhanced perennial ryegrass (Repell II and Triple Play) were overseeded at two different rates in the field. S. parvulus larval populations, their damage, and turfgrass composition were monitored over the course of 3 yr. Significantly fewer larvae were found in plots overseeded with Repell II, whereas Triple Play had no significant effect on larval population density. Endophyte infection was confirmed in approximately 58% of all Repell II shoots, whereas only approximately 31% of Triple Play shoots were infected. Regression analysis, using a segmented model, demonstrated that larval populations declined as the proportion of endophyte-infected perennial ryegrass increased. However, no additional reductions in larval population density were achieved in stands containing >40% endophyte-infected perennial ryegrass. Visual damage varied with cultivar, seeding rate, and year, but generally decreased as the proportion of endophyte-infected perennial ryegrass increased. Although seeding rate had an initial effect on turfgrass composition, these differences were not detected after the first year of the study. Results indicate overseeding existing stands of Kentucky bluegrass with endophytic varieties of perennial ryegrass can reduce S. parvulus larval populations and their damage. However, plant genetic characteristics (i.e., different cultivars) may be overriding determinants of many aspects of plant performance including establishment, tolerance to insect feeding, and expression of endophyte-mediated resistance.

Zoysiagrass Genotype Responses to <I>Sphenophorus venatus vestitus</I> (Coleoptera: Curculionidae)

“…In addition, as a nonchemical control option, endophytic perennial ryegrass (Ahmad et al 1986, Richmond et al 2000 and endophytic tall fescue (Murphy et al 1993) can reduce S. parvulus larval population density and feeding damage in cool season turfgrass. Huang and Buss (2013) similarly studied the effect of overseeding Bermuda grass with endophyte-enhanced perennial ryegrass on S. v. vestitus, for potential use in the southern United States.…”

Effects of cutting frequency and height on alkaloid production in endophyte-infected drunken horse grass (Achnatherum inebrians)

“…Li et al [13] demonstrated that endophytes can improve host resistance to the insect pests Rhopalosiphum padi and Tetranychus cinnabarinus. This type of resistance also occurs in many other turf grasses, and, as a consequence, some insect pests might be controlled through this mechanism [17][18][19][20]. Therefore, alkaloid enhancement in DHG could have important implications for pest management when this species is used as a turf grass.…”

“…In turf culture, there exists an interest in formulating husbandry practices that enhance alkaloid levels, as higher levels typically discourage predators [17][18][19][20]. By contrast, such information can be useful to pastoralists in the formulation of husbandry practices that minimize the exposure of grazing animals to these toxins.…”

Endophyte-mediated tritrophic interactions between a grass-feeding caterpillar and two parasitoid species with different life histories

“…turfgrasses can suppress certain leaf-and stem-feeding insect pests (Breen 1994, Richmond et al 2000, but the value that approach could be compromised if the endemic natural enemies of relatively endophyte-tolerant pests are disrupted. For example, both L. comta and C. bakeri parasitize A. ipsilon on golf courses (Bixby-Brosi and Potter 2010) where the host may encounter and feed on E?…”

“…Neotyphodium lolii, the endophyte associated with perennial ryegrass (Lolium perenne L.), produces ergot alkaloids, peramine, and lolitrems that contribute in varying degrees to resistance (Siegel et al 1987, Siegel andBush 1996;Clay 1991;Bush et al 1997;Schardl et al 2006;Potter et al 2008). Such antiherbivore effects are manifest as serious livestock maladies in pastures (Bacon et al 1986), but in turfgrass settings such as sport fields, lawns, or golf courses, they provide varying degrees of resistance to foliage and stem-feeding insect pests (e.g., Breen 1994;Richmond et al 2000). The black cutworm Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae), however, is relatively endophyte tolerant.…”