Cenchrea Westwood. The 1840
Creators: name: Bahder, Brian W.
name: Zumbado Echavarria, Marco A.
name: Barrantes Barrantes, Edwin A.
name: Helmick, Ericka E.
name: Bartlett, Charles R.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Derbidae
Cenchrea

description: Cenchrea Westwood, 1840
Type species. Cenchrea dorsalis Westwood, 1840.
Amended Diagnosis. Small (~3.0– 3.7 mm), pale cenchreine derbids with variably marked wings. Frons moderately compressed (length at midline exceeding 2-3/4x dorsal width, median carina absent, with transverse carinae near fastigium separating frons from clypeus; lateral carinae of frons and clypeus keeled, bearing row of sensory pustules. The discal region of the pronotum is slightly elevated posteriorly. Forewing with ScP branch at or distad apex of clavus (resulting in short marginal cell). Pygofer with lateral margins bearing caudally directed projections (except ‘slightly convex’ in C. bipunctata; Muir 1918: 419), ventral margin of opening without lobe. Gonostyli long and spatulate, apex rounded to truncate, bearing dorsal projection (very large in C. dorsalis), and medial ventral projection. Aedeagus nearly bilaterally symmetrical, with (C. dorsalis) or without (C. exquisita) apical ventral processes; endosoma complex bearing complex array of retrorse processes. Anal tube elongate, in lateral view ventral margin weakly concave, apex past epiproct and paraproct inflected caudad (C. dorsalis) or ventrad (C. exquisita); in dorsal view broadly spatulate.
Etymology. The etymology of Cenchrea was not provided, but it may have been derived from a Greek town of that name in Troas, where Homer may have resided for a time. The names of Greek towns are typically feminine in gender (as evidenced by the –a termination).
Remarks. Our review of descriptions and available specimens of Cenchrea appear to support Fennah’s (1952: 129) assertion that “… the typical ([subgenus] Cenchrea) includes only C. dorsalis while the other includes exquisita and its allies …”. However, the wing venation features described by Fennah do not appear to be sufficient to define a new genus-group, and available data (both molecular and morphological) is not yet sufficient to support genus-groupings as he proposed. The available descriptions of Cenchrea sexgutatta (viz. Fennah 1952: 132) and Cenchrea bipunctata (viz. Muir 1918: 418–419, as Phaciocephalus Kirkaldy) suggests that these taxa may better be placed in Tico gen. n. once sufficient support is available, except that the position of the Sc vein (distad of the claval apex) suggests Cenchrea. Cenchrea exquisita is more anomalous with the presence of a large process on the lateral margins of the pygofer, the shorter and broader face (vs. Tico gen. n.), and the position of the Sc vein do not support placement in Tico gen. n. Additional data, particularly molecular, is desirable to help resolve the phylogenetic placement of these taxa.
Curiously, the stated distinction between Cenchrea and Contigucephalus in both keys is a “medioventral process present on pygofer” (Fennah 1952: 128, O’Brien 1982: 309). We have not observed a ventral process on the opening of the pygofer, such as seen in Omolicna (e.g., Bahder 2020a, fig. 4), Agoo (Bahder 2020a, fig. 10B), and Phaciocephalus (e.g., Fennah 1967, figs. 112, 116, 120) on the male of any species Cenchrea. It is possible that the intended feature was either the mediolateral process of the male, or (more doubtfully) the pregenital sternite of the female. A better diagnostic feature among the two genera might be that the frons of Contigucephalus is dorsally much more strongly compressed (see Caldwell, 1944, plate 1, fig. 5) than in Cenchrea (Fig. 2). Also, Caldwell (1944: 101) describes red markings on the wings of Contigucephalus (viz. “A scarlet stripe present basad across elytra and mesothorax, another stripe present across furcation of main veins, and a large scarlet spot present at apex of clavus extending almost halfway across elytra”). We have photographs of the species (of uncertain providence) obtained some years ago from Lois O’Brien that support the presence of these markings.
description: Published as part of Bahder, Brian W., Zumbado Echavarria, Marco A., Barrantes Barrantes, Edwin A., Helmick, Ericka E. & Bartlett, Charles R., 2021, A new genus and two new species of planthopper in the tribe Cenchreini (Hemiptera: Auchenorrhyncha: Derbidae) from lowland tropical rainforest in Costa Rica, pp. 369-392 in Zootaxa 4908 (3) on pages 387-390, DOI: 10.11646/zootaxa.4908.3.3, http://zenodo.org/record/4441906