TRIDISCUS-SPOROBOLI AND TRIONYMUS SP (HOMOPTERA, PSEUDOCOCCIDAE) - POTENTIAL NEW MEALYBUG PESTS OF BUFFALOGRASS TURF

In 1988 two grass-feeding mealybugs, Tridiscus sporoboli and Trionymus sp. were collected from heavily damaged buffalograss stands near Mead , NE. Mealybugs were most commonly found feeding within leaf sheaths j ust below the collar or behind leaf axils enclosing the pistillate spi kelets. Injury appeared as foliar yellowing with the most severely inj ured plants turning straw-brown and dying. A statewide survey of mealy bug distribution in Nebraska revealed these mealybugs to be associated with most buffalograss stands sampled. The majority of samples contai ned relatively few mealybugs (8-100), but a few had in excess of 10,00 0 mealybugs per 0.1 m2 section of turf. Serious mealybug injury to buf falograss was observed in only a few isolated situations. Certain buff alograss selections were severely damaged by mealybugs, but others sho wed little injury. Buffalograss resistance to the mealybugs is suggest ed as one explanation for observed differences.