Cabecar, Baumgardner & Ávila, 2006

Baumgardner, David E. & Ávila, Socorro, 2006, Cabecar serratus, a new genus and species of leptohyphid mayfly from Central America, and description of the imaginal stages of Tricorythodes sordidus Allen (Ephemeroptera: Leptohyphidae), Zootaxa 1187 (1), pp. 47-59 : 48-49

Cabecar , gen. n. Baumgardner

Type Species: Cabecar serratus , sp. n.

Diagnosis: Differentiated from all other leptohyphid genera in the larval stage by the following combination of characters: (1) femur with transverse, longitudinal row of acuminate and elongate chalazae; (2) margins of femur with row of elongate chalazae; (2) presence of a two­segmented maxillary palp; (3) absence of the basal spine­like process on one ventral lamella of operculate gill on abdominal segment two; (4) absence of a dorsally elevated, mediolongitudinal ridge on the meso­ and metatibia; and, (5) absence of a dorsal row of stout setae at base of meso­ and metafemur ( Molineri 2003). Adults of the new genus are most similar to those of Asioplax , due to their small size, absence of hindwings, and elongate hindfemora which are greater than three­fourths to equal the length of the hindtibiae and hindtarsi combined. Definitive characters to separate adults of Cabecar

from Asioplax have not yet been identified. However, one character that appears useful for separating male imagoes of the two genera is the ratio of the hindtarsi to hindtibia. For Asioplax , the hindtarsi are approximately two­thirds the length of the hindtibia, while in Cabecar , this ratio is approximately one­half.

Because synapmorphies defining genera within Leptohyphidae have not been definitively established ( Wiersema and McCafferty 2000; Molineri 2003), it is not possible at this point to determine phylogenetic affinities of this new genus with other leptohyphid genera. The new genus does share several characters with Tricorythodes such as a reduced maxillary palp with an apical setae, absence of hindwing pads in both sexes, and absence of the basal spine­like process on one ventral lamella of operculate gill on abdominal segment two. It differs from Tricorythodes and other leptohyphid genera in that the femur possess a transverse, longitudinal row of acuminate and elongate chalaza and also possesses elongate chalaza along the margins of the femora. Additional phylogenetic research will be needed to assess the proper position of the new genus within Leptohyphidae .

Species Included: Cabecar serratus n. sp.

Etymology: Named after the indigenous Cabécar Indians , who inhabit the mountains and low­lying Caribbean costal areas of southeastern Costa Rica and northern Panama on the Talamanca reservation. Their original homeland include the type locality of the new species described herein. Nomenclatural gender: masculine, arbitrarily selected.