LB 22-234 - Hitchhiker’s Guide to Galapagos: Invasive insect use of tourist boats to travel the archipelago

Background/Question/Methods:

Island ecosystems are home to a disproportionately high level of edeminism. Many islands have been negatively impacted by human presence, including the introduction of non-native fauna and flora. The Galapagos islands are no exception, with a large proportion of species introductions being insects. With the goal of further reducing introductions of insects to the islands and preventing the spread of introduced insects among the islands, the Galapagos National Park in 2008 implemented hitchhiking insect prevention protocols for all tourist boats operating within park borders. This study aimed to understand the efficacy of these protocols and evaluate their ability to reduce spread of invertebrates between the islands in the archipelago. We travelled onboard the National Geographic Endeavor II which navigated an easterly and western route itinerary through the islands. We used active and passing trapping methods upon arrival at each new destination to collect all insects on the exterior of the ship.

Results/Conclusions:

Despite the rigor of prevention protocols, several species of introduced insects were caught, notably the invasive parasitic Avian vampire fly among them. We also report the first record of Symphylus found in the Galapagos Islands, suggesting introductions and establishment events are still occurring in the Islands. We demonstrate here there is continued, unintentional movement of introduced insects on a high compliance tourist boat. This is a concern for conservation efforts in the Galapagos where control efforts can lose efficacy with accidental re-introductions.