Relative susceptibility of cereals and pasture grasses to the yellowsugarcane aphid (Homoptera : Aphididae)

摘要

Yellow sugarcane aphid, Sipha flava (Forbes), is an important pest of small grains, Sorghum bicolor (L.) Moench, Saccharum officinarum L., and numerous pasture grass species. Because of the importance of pasture grasses to the economy of the southern states and recent history of the aphid damaging many important pasture grasses, we studied the survival and reproduction of yellow sugarcane aphids on numerous cool- and warm-season grasses, legumes, and forbs to establish the relative susceptibility of the hoist plants. Yellow sugarcane aphid survived on 21 of 21 warm-season grass species, 32 of 32 cool-season grass species, 3 of 19 legume species, and 1 of 4 species of forbs. However, final aphid means of some plant species were lower than the initial infestation. Based on aphid population development, Bromus mollis L., B. biebersteinii Roemer & Schultes, B. marginatus Nees ex Steudel, Agropyron dasystachyum (Hooker) Scribner, and A. intermedium (Host) Beauvois were the best hosts among the cool-season grasses. Echinochloa frumentacea (Link) W.F. Wight, S. bicolor, and Pennisetum orientale (Wild) L.C. Rich were the best warm-season grass hosts. Legumes and forbs were essentially nonhosts of the yellow sugarcane aphid. In a separate but related test, we determined the intrinsic rate of increase values (r(m)) of the aphid on eight species of grasses, Hordeum vulgare L., Triticum aestivum L., and S. bicolor. The r(m) values for the aphid were significantly higher on Bothrichloa caucasica (Trinius) Hubb, Dichanthium sp. Willemet, S. bicolor, and Digitaria ciliaris (Retzius) Keeler than on the other entries. Higher r(m) values were related to shorter prereproductive time, greater aphid fecundity, and increased longevity. The aphid had the lowest r(m) values on Sorghum halepense (L.) Persoon, Panicum virgatum L., and Andropogon gerardii Vitman.