Heilipus squamosus (LeConte, 1824): clarification of the correct name for the “avocado tree girdler” with updates on its biology and distribution (Coleoptera, Curculionidae, Molytinae, Hylobiini)

Abstract

A single species of the genus Heilipus Germar, 1824 is native to the south-eastern United States and was a pest of avocado in Florida in the mid-20th century. Two names—Heilipus apiatus (Olivier, 1807) and H. squamosus (LeConte, 1824)—have both recently been used as the valid name for this species, with H. apiatus also being recently used as the valid name for a species from French Guiana. Confusion surrounding the correct application of these names and the distribution of these species traces back to an erroneous distribution given in Olivier's 1807 description of H. apiatus and, although some authors clarified this previously, there continues to be confusion concerning the correct name. Outside of avocado-producing areas, this species was rarely collected and little was known about its biology. Recent observations on iNaturalist and BugGuide suggest the species is more widely distributed in the United States and less rare than it was previously thought to be. Heilipus squamosus (LeConte, 1824) is recognised as the valid name for the sole species of Heilipus occurring in the United States, while Heilipus apiatus (Olivier, 1807) is a very different species from French Guiana. Heilipus squamosus was previously recorded from eight States in the south-eastern United States and, after examining records from natural history collections, iNaturalist, BugGuide and literature sources, the species is newly recorded from an additional seven States: Arkansas, Kansas, Kentucky, Louisiana, Missouri, Oklahoma and Texas. Though native host plants have been unconfirmed by rearing records, the evidence indicating the possible host plants in the plant family Lauraceae is reviewed.