¿Invasion and spread of the neotropical leafhopper Curtara insularis (Hemiptera, Cicadellidae) in Africa and North America and the role of high-altitude windborne migration in invasive insects

Authors: NARTEY, RITA - Non ARS Employee; Chamorro, Maria; Buffington, Matthew; AFRANE, YAW - University Of Ghana; MOHAMMED, ABDUL - University Of Ghana; OWUSU-ASENSO, CHRISTOPHER - University Of Ghana; AKOSAH-BREMPONG, GABRIEL - University Of Ghana; MANWOVOR-ANBON, PAMBIT ZONG - University Of Ghana; HENDRIX, SOLOMON - University Of Delaware; DAO, ADAMA - University Of Bamako; YARO, SEYDOU - University Of Bamako; DIALLO, MOUSSA - University Of Bamako; SANOGO, ZANA - University Of Bamako; HALBERT, S. - Florida Department Of Agriculture And Consumer Services; BAMOU, ROLAND - National Instiute Of Allergy And Infectious Diseases (NIAID, NIH); NANCE, CATHERINE - Florida Department Of Agriculture And Consumer Services; BARTLETT, CHARLES - University Of Delaware; REYNOLDS, DON - University Of Greenwich; OBIRI-DANSO, KWASI - University Of Ghana; LEHMANN, TOVI - National Instiute Of Allergy And Infectious Diseases (NIAID, NIH)

Submitted to: NeoBiota
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2024
Publication Date: 11/14/2024
Citation: Nartey, R., Chamorro, M.L., Buffington, M.L., Afrane, Y.A., Mohammed, A.R., Owusu-Asenso, C.M., Akosah-Brempong, G., Manwovor-Anbon, P.C., Hendrix, S., Dao, A., Yaro, S., Diallo, M., Sanogo, Z.L., Halbert, S.E., Bamou, R., Nance, C.E., Bartlett, C.R., Reynolds, D., Obiri-Danso, K., Lehmann, T. 2024. ¿Invasion and spread of the neotropical leafhopper Curtara insularis (Hemiptera, Cicadellidae) in Africa and North America and the role of high-altitude windborne migration in invasive insects. NeoBiota. 96:173-189. https://doi.org/10.3897/neobiota.96.130615.
DOI: https://doi.org/10.3897/neobiota.96.130615

Interpretive Summary: Invasive species cost US taxpayers billions of dollars annually in detection, management, and control. The pathway of invasive species into new territories has largely been the result of human involvement via global commerce or other unintended means. However, the possibility that insects are invading new territories and spreading with the aid of high-altitude wind currents remains largely unexplored. This study reports the first record of a South American leafhopper into Africa with 80% of the specimens intercepted at 160 – 190 meters above ground. Given the number of specimens intercepted, we calculate that over the course of a year, millions of these insects migrate through the air. We further explore the possible use of high-altitude windborne dispersal into new territories by examining and summarizing expansion patterns of this leafhopper over the United States. We suggest that the use of high-altitude wind currents, while poorly studied and understood by scientists, may be a commonly used method of dispersal by invasive insects. These new discoveries have the potential to significantly impact current management strategies aimed at mitigating the spread of invasive species and will be useful to federal, state and local regulatory agencies and scientists investigating insect dispersal, migration, and invasion.

Technical Abstract: Invasive insects threaten ecosystem stability, public health, and food security. Documenting newly invasive species and understanding how they reach into new territories, establish populations, and interact with other species remain vitally important. Here, we report on the invasion of the South American leafhopper, Curtara insularis into Africa, where it has established populations in Ghana, encroaching inland at least 350 km off the coast. Importantly, 80% of the specimens collected were intercepted between 160 and 190 m above ground. Further, the fraction of this species among all insects collected was also higher at altitude, demonstrating its propensity to engage in high-altitude windborne dispersal. Its aerial densities at altitude translate into millions of migrants/km over a year, representing massive propagule pressure. Given the predominant south-westerly winds, these sightings suggest an introduction of C. insularis into at least one of the Gulf of Guinea ports. To assess the contribution of windborne dispersal to its spread in a new territory, we examine records of C. insularis range-expansion in the USA. Reported first in 2004 from central Florida, it reached north Florida (Panhandle) by 2008-2011 and subsequently spread across the southeastern and south-central US. Its expansion 51 fits a “diffusion-like” process with 200—300 km long “annual displacement steps”—a pattern consistent with autonomous dispersal rather than vehicular transport. Most “steps” are consistent with common wind trajectories from the nearest documented population, assuming 2—8 hours of wind-assisted flight at altitude. Curtara insularis has been intercepted at US ports and on trucks. Thus, it uses multiple dispersal modalities, yet its rapid overland spread is better explained by its massive propagule pressure linked with its high-altitude windborne dispersal. We propose that high-altitude windborne dispersal is common yet under-appreciated in invasive insect species.