ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Accepted by A.-P. Liang: 6 Jun. 2023; published: 23 Jun. 2023 571 Zootaxa 5306 (5): 571–585 https://www.mapress.com/zt/ Copyright © 2023 Magnolia Press Article https://doi.org/10.11646/zootaxa.5306.5.5 http://zoobank.org/urn:lsid:zoobank.org:pub:C284A22F-6963-494C-A561-30C51916FCBE Licensed under Creative Commons Attribution-N.C. 4.0 International https://creativecommons.org/licenses/by-nc/4.0/ A new species of planthopper in the genus Shellenius (Hemiptera: Fulgoroidea: Derbidae) from palms in Costa Rica BRIAN W. BAHDER 1,2 , MARCO A. ZUMBADO ECHAVARRIA 4,5 , EDWIN A. BARRANTES BARRANTES 4,6 , ERICKA E. HELMICK 1,3 & CHARLES R. BARTLETT 7 1 University of Florida, Department of Entomology and Nematology - Fort Lauderdale Research and Education Center; 3205 College Ave., Davie, FL 33314-7719, USA. 2 � bbahder@ufl.edu; https://orcid.org/0000-0002-1118-4832 3 � ehelmick@ufl.edu; https://orcid.org/0000-0002-5153-0891 4 Universidad de Costa Rica—Sede San Ramón, Departamento de Ciencias Naturales, de la Iglesia el Tremedal 400 mts al Oeste carretera hacia San Pedro, San Ramón, Alajuela, Costa Rica. 5 � marco.zumbado@ucr.ac.cr; https://orcid.org/0000-0002-2591-7662 6 � edwin.barrantes@ucr.ac.cr; https://orcid.org/0000-0001-9565-2105 7 University of Delaware, Department of Entomology and Wildlife Ecology, 250 Townsend Hall, Newark, DE 19716-2160, USA. � bartlett@udel.edu; https://orcid.org/0000-0001-9428-7337 Abstract The genus Shellenius is a small taxon of planthoppers in the family Derbidae (Otiocerinae: Otiocerini) found in the eastern United States and Mesoamerica. A new species of Shellenius associated with palms is herein described from Costa Rica. Molecular data for the barcoding region cytochrome c oxidase subunit I (COI) and 18S rRNA gene is provided to produce a preliminary phylogenetic tree for related taxa and support placement of the novel taxon in Shellenius. A review of Fowler type material suggests that Otiocerus interruptus Fowler is a Shellenius species and is here transferred to that genus as Shellenius interruptus new combination. Key words: taxonomy, phylogeny, biodiversity, systematics, survey, Otiocerini Resumen El género Shellenius es un taxón pequeño de chicharritas de la familia Derbidae (Otiocerinae: Otiocerini) que se encuentra en el este de los Estados Unidos y Mesoamérica. Se describe aquí una especie nueva de Shellenius asociada con palmas en Costa Rica. Se proporcionan datos moleculares para el gen de la subunidad I (COI) del citocromo c oxidasa de la región del código de barras y el gen 18S ARNr para producir un árbol filogenético preliminar para taxones relacionados y apoyar la colocación del nuevo taxón en Shellenius. Una revisión del material tipo Fowler sugiere que Otiocerus interruptus Fowler es un especie de Shellenius y aquí se transfiere a ese género como una nueva combinación de Shellenius interruptus. Palabras clave: taxonomía, filogenia, biodiversidad, sistemática, encuesta, Otiocerini Introduction The genus Shellenius Ball, 1928 is a small taxon of planthoppers in the family Derbidae (Otiocerinae: Otiocerini) that is currently comprised of five species (see below) two from the USA and three from Mesoamerica. The derbid subfamily Otiocerinae are generally elongated, fragile forms with the wings projecting well beyond the body (more than 2.5x longer than broad), with the head strongly compressed (bearing sensory pits along margins), the clavus usually open (the Pcu+A1 does not reach the claval margin, instead merges with CuP), and the jugal region of the hind wings bear a stridulatory plate with a concave external margin (Fennah 1952, Emeljanov 1996). Compared with other tribes of Otiocerinae in the New World (viz. Patarini, Sikaianini), the Otiocerini have a strongly projected head.