ARS | Publication request: The discovery of Megalota in the Neotropics, with a review of the New World species (Lepidoptera: Tortricidae: Olethreutini)

Submitted to: Zootaxa
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 15, 2008
Publication Date: November 2, 2009
Citation: Brown, J.W. 2009. The discovery of Megalota in the Neotropics, with a review of the New World species (Lepidoptera: Tortricidae: Olethreutini). Zootaxa. 2278:1-50.

Interpretive Summary: Caterpillars of small moths, known as leaf-rollers, cause millions of dollars in damage each year to ornamental, forest, and crop plants. In addition, many leaf-roller moths pose a significant threat as potential invasive pests to the U.S. This research recognizes the occurrence in the Western Hemisphere of a group formerly known from African, Australia, and the Oriental regions. Larvae appear to be specialists on a plant group that includes manihot, an important tropical fruit, phyllanthus, a medicinal plant, and castor-bean, an invasive weed. Twenty-one species new to science are described, and illustrations on all known New World species are provided for their identification. This study will be of interest to scientists studying the biodiversity of the New World tropics, plant-insect interactions, and global biogeography, as well as action agencies such as APHIS-PPQ, whose goals include the exclusion and detection of potential insect pests.

Technical Abstract: Megalota Diakonoff, previously known from Australia, the Orient (India, Sri Lanka, New Guinea, Indonesia), Madagascar, and Africa, is reported from the Neotropics for the first time. Three previously described New World species (i.e., Megalota submicans (Walsingham), n. comb.; M. delphinosema (Walsingham), n. comb.; and M. plenana (Walker), n. comb.) were concealed within incorrect generic assignments or as “unplaced” species (i.e., lacking contemporary generic assignments). Twenty-one new species are described and illustrated: M. synchysis (TL: Venezuela), M. peruviana (Peru), M. aquilonaris (Mexico), M. vulgaris (Costa Rica), M. cacaulana (Brazil), M. macrosocia (Ecuador), M. ochreoapex (Costa Rica), M. spinulosa (Costa Rica), M. simpliciana (Costa Rica), M. jamaicana (Jamaica), M. ricana (Costa Rica), M. ceratovalva (Venezuela), M. bicolorana (Costa Rica), M. longisetana (Costa Rica), M. deceptana (Costa Rica), M. crassana (Costa Rica), M. gutierrezi (Costa Rica), M. chamelana (Mexico), M. beckeri (Brazil), M. flintana (Brazil), and M. pastranai (Argentina). Males of the genus are characterized by three distinctive features of the genitalia: the uncus consists of a pair greatly expanded, flattened, variably rounded lobes, densely covered with spines and setae; the valvae are narrow with an elongate, apically spined process (= labis) arising from the base of the costa; and the juxta has a narrow, J-shaped sclerotized posterior edge. Five species have been reared from Croton spp. (Euphorbiaceae) in Costa Rica, and these represent the first host plant records for the genus.