On the identity of a U.S. intercepted Conotrachelus Dejean (Coleoptera: Curculionidae) on avocado (Persea americana)

Authors: Chamorro, Maria; BARCLAY, MAXWELL V. - London Natural History Museum

Submitted to: Biodiversity Data Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2018
Publication Date: 11/2/2018
Citation: Chamorro, M.L., Barclay, M.L. 2018. On the identity of a U.S. intercepted Conotrachelus Dejean (Coleoptera: Curculionidae) on avocado (Persea americana). Biodiversity Data Journal. 6(e26362):1-32.

Interpretive Summary: A weevil species recently intercepted at a U.S. port entry on a shipment of avocados closely resembled a widely distributed native species. Upon further scrutiny and taxonomic research of a species-rich group of seed-feeding weevils, the species was determined not to be native. This species belongs to the same group/genus as the pecan weevil, plum curculio, the avocado seed weevil, among other agricultural pests. This research presents the first images and discussion and comparison of the physical features that will assist in distinguishing the native from non-native species of a subset of this large seed-feeding weevil group. In addition, images of the two serious weevil pests in the same genus are also illustrated. This weevil may pose a serious risk to the nation’s avocado industry. This study will be indispensable to port inspectors and identifiers for the detection and determination of a potentially serious pest. It will also inform entomologists, resource managers, farmers, biologists, foresters, and the general public.

Technical Abstract: The multimillion-dollar avocado industry is threatened by a number of serious insect pests, including at least six Curculionidae species. Of these, two Conotrachelus species are known to develop and feed on avocados: Conotrachelus aguacatae Barber and Conotrachelus perseae Barber. Recently, an unrecognized Conotrachelus species was intercepted with avocado by the USDA at a U.S. port of entry. The species most resembles the U.S. native Conotrachelus posticatus Boheman. This study aims to determine the identity of this possible new non-U.S. native avocado pest and provide the tools necessary to distinguish among phenotypically similar species. The new weevil recently intercepted with avocado at a U.S. port of entry is Conotrachelus lobatus Champion. This study includes high-resolution images for six Conotrachelus species, including C. aguacatae and C. perseae, as well as the first images of C. lobatus, C. scoparius Champion, and C. squamifrons Champion. Characters are imaged and discussed in order to unequivocally distinguish C. posticatus from other similar Conotrachelus species belonging to Schoof's Group II. Some characters of particular importance are the shape of the metauncus; shape of elytral lateral margin and presence/absence of costate first and second elytral intervals.