Lettuce Infectious Yellows Virus Infecting Watermelon, Cantaloupe, Honey Dew Melon, Squash, and Cushaw in Texas. R. S. Halliwell, Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843. J. D. Johnson, Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843. Plant Dis. 76:643. Accepted for publication 17 February 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0643E.

In 1988, Lettuce infectious yellows virus (LIYV) was detected in cantaloupe plant tissue collected in southwestern Mexico. During late summer and fall of 1991, LIYV was identified infecting cantaloupe (Cucumis melo L. var. cantalupensis Naudin) and honeydew melon (C. m. inodorus Naudin) in north central Texas, watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) in central Texas, and squash (Cucurbita pepo L.) and cushaw (Cucurbita moschata Duchesne) along the upper Gulf Coast of Texas. The incidence of LIYV infections was noted to coincide with the presence of the virus vector, Bemisia tabaci (Gennadius). Infected plants were stunted and leaves were yellow and cupped. Infected foliage died from the crown outward. In many cases, LIYV was observed in multiple infections with one or more of the endemic cucurbit viruses, i.e., watermelon mosaic virus, papaya rings pot virus, and zucchini yellow mosaic virus. LIYV was identified on the basis of virion morphology (flexuous rods 1,200-1,800 nm) and serospecificity (ELISA, ISEM) (1). LIYV was first reported in the desert southwest in 1982 (2). This is the first report of LIYV diseases in Texas.

References: (1) J. K. Brown and B. T. Poulos. J. Rio Grande Valley Hortic. Soc. 42:13, 1989. (2) J. E. Duffus et a!. (Abstr.) Phytopathology 72:963, 1982