Seminar: Twolined Spittlebug (Prosapia bicincta): A Pasture Pest in Paradise

Valued at more than $68 million annually, livestock ranching is a highly productive and extremely important industry on all major islands in the State of Hawaii. Now however, the Hawaiian livestock industry faces severe threats from exotic pests such as the recently discovered twolined spittlebug (TLSB), Prosopia bicincta. It is not known when the TLSB was introduced into Hawaii however, they were first detected in the Kailua-Kona area on Hawai`i Island in September of 2016 where it had caused severe damage to nearly 2,000 acres of rangeland. The pest has since rapidly expanded its range and is now causing similar damage to an estimated 178,000 acres. In highly infested areas there has been nearly 100% die back of the dominant and key range grasses. The loss of these grasses provides entry for the establishment of many undesirable and invasive plants, and dramatic reductions in stocking rates for livestock, and significant deterioration of ecological condition of the range. On going research since 2017 has focused on exploring the biology and ecology of the pest in Hawaii through field surveys, evaluating different grass species for host-plant resistance and damage thresholds, conducting pesticide trials, and developing Integrated Pest Management strategies to control the pest and mitigate the damage it causes. The introduction of twolined spittlebug into Hawaii illustrates the importance biosecurity measures for isolated island communities.