The twolined spittlebug, Prosapia bicincta (Say) (Hemiptera: Cercopidae), is an important insect pest of turfgrass in the eastern United States. Although twolined spittlebug infests most warm-season turfgrasses, the influence of low and high relative humidity (RH) on the expression of feeding damage in warm-season turfgrasses is not well understood. Experiments were conducted in which five warm-season turfgrasses were caged with ten twolined spittlebug adults and exposed to 40% and 95% RH for 5 days. The extent of damage was measured with a SPAD meter (chlorophyll content), and ratings of greenness, yellowness, and purpleness were obtained using a scale system. Physiological parameters such as stomatal conductance (GS), photosynthesis (A), evapotranspiration (E), and water use efficiency (WUE) were measured. Under both 40 and 95% RH, bermudagrass [Cynodon L.C. Rich, spp.] exhibited injury symptoms after twolined spittlebug exposure. The rate of A was lower in the presence of twolined spittlebug in bermudagrass under both RHs. Injury symptoms in centipedegrass [Eremochloa ophiuroides (Munro) Hack] were only observed under high-RH conditions, whereas in zoysiagrass [Zoysia matrella (L.) Merrill.] symptoms were only observed under low RH. Minimal levels of symptom expression were observed in St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze], and no feeding symptoms were observed in seashore paspalum [Paspalum vaginatum Sw.] under low RH. Overall, the presence of twolined spittlebug A was influenced by high RH, whereas WUE was affected by low RH in most of the turfgrass genotypes.

两条线的瓢虫，Prosapia bicincta（Say）（半翅目：Cercopidae），是美国东部草坪草的重要害虫。尽管两线长尾bug感染了大多数暖季型草​​坪草，但对高低相对湿度（RH）对暖季型草坪草中进食损伤表达的影响尚不清楚。进行了实验，其中将五个暖季型草坪草与十个两线成虫的成年bug关在一起，并在40％和95％的相对湿度下暴露5天。用SPAD计（叶绿素含量）测量损伤程度，并使用刻度系统获得绿色，黄色和紫色的等级。诸如气孔导度（GS），光合作用（A），蒸散量（E）和水分利用效率（WUE）被测量。在40％和95％的相对湿度下，百慕大鼠尾草[ Cynodon LC Rich，spp。]在经过两次线状的瓢虫暴露后表现出损伤症状。在两种相对湿度下，在百慕大草中都存在两个内衬的瓢虫时，A的比率较低。仅在高RH条件下观察到了百足草[ Eremochloa ophiuroides（Munro）Hack]的损伤症状，而在zoysiagrass [ Zoysia matrella（L.）Merrill。]症状仅在低RH条件下观察到。在St. Augustinegrass [ Stenotaphrum secundatum（Walt。）Kuntze]中观察到最低水平的症状表达，在海滨雀spa中未观察到任何进食症状[低相对湿度下的[ Paspalum阴道肿瘤]。总体而言，在大多数草皮草基因型中，两株线状瓢虫A的存在受高RH影响，而WUE受低RH影响。