Location: Systematic Entomology LaboratoryTitle: Molecular and morphological tools to distinguish Scyphophorus acupunctatus Gyllenhal, 1838: a new weevil pest of the endangered Eggers Agave from St Croix, US Virgin Islands Author
Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2016
Publication Date: 5/27/2016
Citation: Chamorro, M.L., Persson, J., Torres, S., Keularts, J., Scheffer, S.J. 2016. Molecular and morphological tools to distinguish Scyphophorus acupunctatus Gyllenhal, 1838: a new weevil pest of the endangered Eggers Agave from St Croix, US Virgin Islands. Proceedings of the Entomological Society of Washington. 118(2):218-243. Interpretive Summary: The Agave snout weevil (Scyphophorus acupunctatus) is one of the most destructive pests of agave, affecting global industries of tequila, mezcal, perfume, henequen, nardo, and fiber manufacturing as well native plants where the weevil becomes accidentally established. This is the first record of Scyphophorus acupunctatus in St Croix, where it represents a threat to an endangered agave. The necessary morphological, behavioral and molecular tools to unequivocably identify the weevil or any part at any stage is provided. Detection and rapid identification of this weevil is crucial towards its control and to mitigate the risk it poses to valuable and vulnerable natural resources. This publication will be used by entomologists, botanists, foresters, conservation biologists, identifiers and the general public.
Technical Abstract: The Agave Snout Weevil (ASW) or Sisal Weevil, Scyphophorus acupunctatus Gyllenhal, is one of the most destructive pests of agave plants, capable of destroying up to 70% of commercial crops, costing millions of dollars in damage to global industries including tequila, mezcal, perfume, henequen, nardo, pulque and fiber manufacturing. From its native range in the SW United States and Mexico it has tracked its host plant and invaded countries in Europe, Central America, the Caribbean, East and South Africa. Scyphophorus acupunctatus has been associated with a broad range of host plants within Asparagaceae including the subfamilies Nolinoideae and Agavoideae. Scyphophorus acupunctatus is here reported for the first time in St. Croix, U.S. Virgin Islands (USVI) where it threatens Agave eggersiana Trel., a USVI endangered, endemic century-plant. We provide molecular, morphological, and behavioral characters to successfully distinguishing Scyphophorus species at all developmental stages. We identified seven new larval characters on the mandibles and characters relating to the chaetotaxy of the labrum and labio-maxillary complex. In the pupae, the difference in number and placement of rostral setae were also found to be diagnostic. We analyzed 2 genes (mtCO1 and EF1a) across 20 and 11 taxa, respectively, to confirm the identity of the immatures. We provide management recommendations for the protection of Agave eggersiana against the threat posed by ASW. We also report, for the first time, the presence of Sphenophorus cubensis (Buchanan) in St. Croix and Scyphophorus yuccae in Panama on Hesperoyucca whipplei (Torr.) Trel.