|GOTZEK, DIETRICH - University Of Illinois|
|AXEN, HEATHER - Smithsonian Institute|
|HELMS-CAHAN, SARAH - University Of Vermont|
Submitted to: Molecular Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2014
Publication Date: 12/6/2014
Citation: Gotzek, D., Axen, H.J., Helms-Cahan, S., Shoemaker, D.D. 2014. Global Invasion History of the Tropical Fire Ant, Solenopsis geminata: A Stowaway on the First Global Trade Routes. Molecular Ecology. 24:374-388.
Interpretive Summary: Fire ants are considered significant ecological, agricultural, and public health pest throughout their invasive range in the U.S.A. A research entomologist at the Center for Medical, Agricultural, and Veterinary Entomology, USDA-ARS, Gainesville, Florida, in collaboration with scientists from the University of Illinois and University of Vermont, describes here the results of a study aimed at reconstructing the global invasion history of the invasive Tropical Fire Ant. Results show that the Old World populations are introduced and their movement is highly consistent with historic trading patterns, suggesting that Spanish trade most likely introduced the Tropical Fire Ant to Asia in the 16th century. This study provides the first documented case of a biological invasion of a highly invasive and globally distributed pest species due to the earliest stages of global commerce. These findings highlight the potential importance of historic trade routes in setting up current biogeographic patterns.
Technical Abstract: Biological invasions are largely thought to be contemporary, having recently increased sharply in the wake of globalization. However, human commerce had already become global in scope by the mid-16th century, when the Spanish connected the New World with Europe and Asia via their Manila galleon and West Indies trade routes. We use genetic data to trace the global invasion of one of the world’s most widespread and invasive pest ants, the Tropical Fire Ant, Solenopsis geminata. Our results show that the Old World populations are introduced and their movement is highly consistent with historic trading patterns, suggesting that Spanish trade most likely introduced the Tropical Fire Ant to Asia in the 16th century. We identify southwestern Mexico as the most likely source for the invasive populations, which is consistent with the early use of Acapulco as the major Spanish port on the Pacific Ocean. From there, the Spanish galleons brought silver to Manila, which served as a hub for trade with China. The genetic data document a corresponding spread of S. geminata from Mexico via Manila to Taiwan and from there throughout the Indo-Pacific. Our descriptions of the worldwide spread of S. geminata represent the first documented case of a biological invasion of a highly invasive and globally distributed pest species due to the earliest stages of global commerce.