Title: Feeding, Mating, and Flight Dispersal Behavior of the Invasive Pest Species, Lycorma delicatula (Hemiptera: Fulgoridae)
Abstract:The spotted lanternfly, Lycorma delicatula, is an invasive fulgorid bug species that was recently accidentally introduced into North America, likely from indigenous populations in China. This incipient pest of vineyards, fruit orchards, and hardwood forests of the U.S. has now spread from a quarantine zone in a small portion of one county in eastern Pennsylvania in 2015 to now comprise in 2018 over 6,900 square miles of infestation, with recent detections reported also in two neighboring states – New Jersey and Virginia. There is great concern of this species’ certain continued spread over a broader geographic area in North America if it cannot be controlled. In 2017 we saw a progression of adult behaviors that culminated in a mass flight dispersal of thousands of adults followed by mating and egg laying. After one to two weeks of intense early-season feeding, short flights occurred indiscriminately from the foliage of one tree to another or between bushes, trees and vines. At the peak of adult population abundance in 2017 these flights became more prevalent and lengthier, with adults of both sexes observed to launch themselves into the wind from all types of host and non-host trees or from porches, posts and other human-made structures. The fairly straight-line-level or gradually descending flight trajectories allowed the flying adults to traverse only usually 10 to 50 meters of ground in one episode, showing no preference for landing on any particular species of plant or inanimate object. They would then crawl up a nearby vertical structure and launch themselves into flight again. Thousands of adult L. delicatula undertook such flights together on any day, creating massive swarms in local areas. We developed a novel technique to study the in-flight wind-orientation of adults during their “first-aim-then-shoot” flight dispersal bouts.