Bittacomorphella sackenii, von Roder, 1890

Fasbender, Andrew & Courtney, Gregory W., 2017, A revision of Bittacomorphinae with a review of the monophyly of extant subfamilies of Ptychopteridae (Diptera), Zootaxa 4309 (1), pp. 1-69 : 38

Bittacomorphella sackenii species group

Diagnosis. Adult ( Figs. 7 d, 13). Scutum black or dark brown, uniform coloration; epandrium quadrate with epandrial claspers at lateral apices, without medial suture, epiproct not apparent; hypandrium acutely triangular, basal division narrowing well before terminal division.

Description. Larvae and pupae unknown. Adult. Fringe of postocellar setae present. Clypeus elongate, 2x as long as wide. Shelf over maxillary palpus prominent, triangular. Hypopharynx highly reduced or narrow, acute. Labium elongate, extending past apex of clypeus, labella small (shorter than labium), adhered medially. Antepronotum without lobes. Scutum dark brown or black, with at most a weak light colored patch adjacent to scutellum. Metapleural suture complete, setose prominence below halter. Legs with single white band covering distal apex of the 1st–3rd tarsomeres, 4th and 5th tarsomeres infuscate. Epandrium platelike, quadrate, anterior and lateral margins straight joining at right angle, epandrial lobes absent, posterior margin at most weakly emarginated with epandrial claspers placed at posterior corners, internal fold present. Epandrial claspers strongly curved medially, pointed. Epiproct absent, hypoproct ovoid. Subepandrial sclerite V-shaped, arms articulating epandrial claspers. Parameres separate; simple or bifurcate. Gonopods with elongate cylindrical gonocoxite, apex of gonostylus rounded, not closely assocated with hypandrium. Hypandrium acutely triangular, basal division blending seamlessly into terminal division, very narrow. Superaedeagal membrane not inflated. Aedeagus with lateral ejaculatory processes curving posteriorly, ventral portion weakly developed. Apical apodemes of aedeagus simple, subaedeagal sclerite variable.

Taxonomic notes. The Bl. sackenii species group is proposed to include Bl. sackenii , Bl. furcata , and Bl. pacifica . The most compelling characters uniting these species are in the male genitalia: primarily the massive, quadrate epandrium with epandrial claspers located apically, and the hypandrium forming a narrow, acute triangular shape when viewed ventrally.

Figures

FIGURE 7. Bittacomorphine male wings. a. Bittacomorpha clavipes; b. Bi. occidentalis; c. Bittacomorphella pacifica Alexander; d. Bl. sackenii Von Röder; e. Bl. furcata sp. nov.; f. Bl. esakii Tokunaga; g. Bl. fenderiana; h. Bl. jonesi Johnson; i. Bl. nipponensis Alexander; d. Bittacomorphella thaiensis Alexander. All scale bars 1 mm except “ b ” (2 mm).