Unusual pathways and risks: Pachodynerus nasidens and aircrafts
Pachodynerus nasidens (Hymenoptera: Vespidae) is a mud-nesting wasp native to South and Central America and the Caribbean. It has also been recorded from several Pacific islands including Hawaii, Polynesia, Micronesia and Japan. In its native range, P. nasidens is known to use man-made cavities (e.g. window crevices, keyholes, electrical sockets) to construct nests. In Australia, P. nasidens was first detected in 2010 in Northern Brisbane during a routine quarantine inspection of commodities initially received at the Brisbane Port. In 2012, the insect was also found at Brisbane Airport. As a series of serious safety incidents related to the obstruction of vital airspeed measuring probes (i.e. pitot probes) on aircrafts were reported at the Brisbane Airport, a study was initiated to verify whether these were associated with P. nasidens. From February 2016 to April 2019, replica pitot probes and several traps were installed at Brisbane Airport and regularly monitored. Blocked probes were removed and placed in fine mesh bags to observe insect emergence. Results showed that all nests found in blocked probes were made by P. nasidens, and that a peak of nesting activities took place during summer months. Within the airport, it was also observed that probes placed closer to natural habitats (e.g. grasses) were more likely to be blocked than those further away. These results show that P. nasidens has the potential to pose a significant risk to aviation safety and that aircraft could also contribute to its further spread. P. nasidens is not a plant pest, but this particular case illustrates the diversity of pathways for spread and the unexpected risks presented by some invasive species to human activities.
Sources
House APN, Ring JG, Shaw PP (2020) Inventive nesting behaviour in the keyhole wasp Pachodynerus nasidens Latreille (Hymenoptera: Vespidae) in Australia, and the risk to aviation safety. PLoS ONE 15(11), e0242063. https://doi.org/10.1371/journal.pone.0242063