Susceptibility of Bermudagrass Cultivars to Eoreuma loftini (Lepidoptera: Pyralidae) in Subtropical Mexico

Abstract

Susceptibility of eight bermudagrasses (Tifton 68, Tifton 78, Tifton 85, Gigante, Brazos, Cruza 1, Callie, and NK 37) to the Mexican rice borer, Eoreuma loftini (Dyar) was evaluated monthly during 1994 in northern Tamaulipas, northeastern Mexico. Damage by E. loftini occurred year around, peaking in April and December. Borer attack was reduced substantially after mowing the pastures to 3-5 cm height. Susceptibility of the cultivars to borer damage was influenced by stolon width, an important characteristic for E. loftini tunneling. This relationship between stolon width and borer damage was explained closely (R 2 = 0.86) by the curvilinear model y = (1.2 + 0.1757 x 3 ) 2, where y = borer damage and x = stolon diameter. The widest stemmed bermudagrass, and hence the most susceptible to E. loftini, was Tifton 68. Tunneling behavior of E. loftini, as affected by stem width of host plants, is discussed.