Spotted lanternfly dispersal and reproductive stage: Using stable isotope mark and recapture and flight mill studies to study adult movement

Spotted lanternfly, SLF, (Lycorma delicatula: Fulgoridae:Hemiptera) is a large, invasive Asian plant hopper that poses a serious threat to vineyards and other crops through its large populations and voracious appetite. Since its 2014 arrival in Pennsylvania, USA it has spread to 18 states, largely through accidental human-assistance. However, SLF is known to travel broadly though the landscape, changing food plant preferences as they mature. We present two studies of adult SLF movement. In the first study, an Ailanthus altissima (Simaroubaceae: Sapindales) was treated with a stable isotope of nitrogen, N15. Adults of nymphs that fed on that tree have an increased proportion of N15 in their wings. A total of 25 A. altissima trees were selected at distances varying from 10 m to 2000 m from the treated tree and adults were collected weekly. Wings were pooled for each site for each week by sex, and analyzed for nitrogen isotopes. The study was replicated at two sites in 2024. A subset of 10 males and 10 females were dissected to ascertain mating status for each week. In the second study, 5 males and 5 females were collected weekly and flight capacity was assessed using a flight mill. The individuals were then dissected for mating status. Together these two studies help to understand the dispersal range and seasonal timing of SLF adult movement.