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Turfgrass is subject to attack by a variety of insect pests. However, there has been no research on the sod webworm pests associated with turfgrass in Virginia and little research on habitat preferences of other insect pests of turf. The purpose of this research was to contribute to the basic knowledge of the biology of sod webworm species in Virginia. There are at least 16 sod webworm species found to occur in Virginia; all can be identified to species level by forewing color patterns. The species complex is distributed nearly evenly throughout Virginia with some species adapted to higher elevations (700m). The species complex is present from spring to late fall. The number of generations and peak flight periods differ depending on the species. Most species were sampled in low numbers except Parapediasia teterrella (Zincken). Accumulated degree-days can predict an additional years worth of occurrence of Microcrambus elegans (Clemens), Crambus lagueatellus Clemens, Pediasia trisecta (Walker) , and Agriphila ruricolella (Zeller), in the Appalachian region of Virginia. Behavior patterns of P. teterrella. M. elegans, and A. ruricolella adults indicate the utilization of shrubs instead of turfgrass as resting sites during the day. In addition, 10 species of 7 families of insects were found to inhabit tall fescue, ryegrass, and bluegrass in Virginia. / Master of Science

Please read the abstract in the section 00front of this document / Dissertation (MSc (Entomology))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted

A preliminary experiment was conducted to determine the effects of salinity and moisture stress on the pathogenicity of root-knot nematodes (RKN) in turfgrass plants. The results indicated that RKN infection adversely affected both visual and functional parameters of bentgrass. Salinity and moisture stress further exaggerated the damage caused by RKN. Under well-watered conditions, the effects of SWC and RKN infection on bentgrass plants were studied. Applications of Swe at 0.5 liter ha⁻¹ and 1.0 liter ha⁻¹ effectively enhanced bentgrass growth under both RKN-free and RKN-infected condition. It was shown that RKN caused less damage to SWC-treated plants than to non-treated plants. In addition, a soil drench of 0.5 liter ha⁻¹ and 1.0 liter ha⁻¹ at 10 day intervals was required to enhance bentgrass growth under RKN-free and RKN-infected conditions, respectively. The effects of seven SWC treatments on the growth of nematode-free and RKN infected bentgrass plants were tested under three irrigation regimes. Rooting and leaf moisture parameters, quality and clipping yield were all improved to some degree by SWC applications. High dosage SWC treatments, applied as a soil drench at one liter ha⁻¹ every 10 days, were most effective in improving plant growth. Application of SWC was more beneficial to RKN-infected plants than RKN-free plants, and to abiotically stressed plants than to abiotic stress-free plants. In a separate study, seaweed application was also shown to enhance both top growth and root growth of lance nematode (Hoplolaimus galeatus) or RKN infected bentgrass grown under drought or salinity stress condition. With SWC application, almost all of the symptoms caused by nematode infection and the abiotic stress were partially overcome. In addition, root development, leaf water status and clipping yield were all improved. It was apparent that soil drench SWC treatments were more effective in enhancing bentgrass growth than foliar Swc treatments. Application of SWC slightly reduced the number of nematodes per unit of fresh root (for RKN) and per unit weight of soil (for lance nematodes). Protein extracted from SWC-treated or non-treated ryegrass plants under different stress conditions indicated that SWC altered plant protein synthesis, possibly by inducing selective gene expressions. / Ph. D.