Cardiacephala Macquart

Ferro, Gustavo Borges & Marshall, Stephen A., 2018, A revision of the Neotropical ant-like genus Cardiacephala Macquart, including Plocoscelus Enderlein syn. nov. (Diptera: Micropezidae, Taeniapterinae), Zootaxa 4429 (3), pp. 401-458 : 406-407

Cardiacephala Macquart

Cardiacephala Macquart, 1843: 399 . Type species: Musca longipes Fabricius (orig. des., preoccupied and replaced by Calobata guttata Walker, 1852 ).

Rhoecius Enderlein, 1922:227 . Type species: Rhoecius vulgus Enderlein, 1922 (orig. des.).

Plocoscelus Enderlein, 1922: 226 . Type species: Calobata arthritica Wiedemann, 1830 (orig. des.). New synonym

Diagnosis. Body length 6–10 mm, wing length 4–6 mm. Shiny yellow to dark brown (sometimes slightly ferruginous) or black, ant-like in appearance. Arista pectinate, hairs on upper side only. Mid and hind femora conspicuously swollen distally.

Head: Palpus almost triangular, broadened basally and gradually tapering to apex ( Fig. 37 ), rarely strongly convex ventrally ( Fig. 93 ). Clypeus yellow to dark brown or black, sometimes with pale microsetulae. Frontal vitta flat, fronto-orbital plates together equal to or wider than frontal vitta. Vertex rounded or flattened. Paracephalon smooth (without swelling), swollen and conical or with rounded swelling. Head chaetotaxy with one stout outer vertical, inner vertical, orbital, and postocellar setae; 2–3 frontal setae ( Fig. 14 ). Line of supracervical black setae sometimes present.

Thorax: Cervical sclerite with a vertical groove, posterior portion slightly longer and modified in females of some species. Postpronotal lobe bare. Two notopleural, one dorsocentral, one supraalar, one postalar and one scutellar setae. Scutellum triangular and upturned, convex and displaced posteriorly only in C. camptomera and C. spinosa . Mid and hind tibia flattened, sulcate on outer face, groove strongly pronounced and curved in some species. Tarsus of mid and hind legs white, but tarsomeres 2–5 always covered by dark brown pubescence (sometimes giving the impression that they are brown). Wing hyaline with dark bands (including preapical dark and narrow pigmentation or three dark spots), or dark with round hyaline spots (at least in the upper half). Three costagial setae, inner one longer and strong. Anal cell long, A1+CuA2 as long as CuA2 (less than half as CuA2 only in C. conifera ). Crossvein r-m sometimes with small black spot.

Abdomen: Anterior half of abdominal syntergite 1+2 with pale setae, usually longer laterally. Syntergite 1+2 at least 1.5x length of T3. Pleural membrane colour varies interspecifically, often predominantly dark or white and sometimes with rusty red areas. Males usually with prominent pleural sac on P2 (no species definitively lack this structure, but we had no adequate material of C. conifera , C. schildi , C. peruana and C. velutinosa ; C. acuminata , C. angularis , C. camptomera , C. punctipennis , C. spinosa and C. vitrata males were not examined). Female abdomen: Oviscape elongate, but no more than half as long as abdomen. Bursa copulatrix large, sometimes densely rugose ( Fig. 21 ). Spermathecae and ducts species-specific. Spermathecae cylindrical, spherical or tapered basally and distally swollen. Single spermathecal duct often broad distally before tapering to a short spermathecal stem. Single spermatheca often cylindrical, sometimes spherical or vestigial. Paired spermathecal duct usually with a narrow basal half and a broader distal half (sometimes with a distal ring-like swelling), rarely uniform in width. Paired spermathecal duct stems sometimes with swellings of different sizes, appendices, or finger-like processes. Male abdomen: Sternite 5 copulatory fork arms generally converging ( Figs. 49 , 52 ) and always with small dark teeth on inner portion, arms abruptly pointing inward ( Fig. 15 ) only in C. arthritica , C. modesta , C. picina and abruptly pointing ventrally ( Fig. 23 ) only in C. brevipennis and C. podagrica . Cercus large and distinct. Ejaculatory apodeme variable in size and species-specific, length variations mainly in the blade above the sperm pump. Distiphallus usually long, similar in length to epandrium and usually ending in phallic bulb; distal distiphallus present in C. cinnameus and C. setosa . Phallic bulb usually subequal in length and width, cylindrical (about three time as long as wide) only in C. brevipennis and C. planivertex .

Figures

FIGURES 37–39. Cardiacephala erugata. 37, male, lateral view. Abbreviation: plp—Palpus; 38, male, dorsal view; 39, male genitalia, lateral view.

FIGURES 93–96. Cardiacephala umbra. 93, female, dorsolateral view; 94, female genitalia, ventral view; 95, male, dorsolateral view; 96, male genitalia, lateral view.

FIGURES 12–15. Cardiacephala arthritica. 12, female, Costa Rica; 13, Female genitalia with taxonomically significant structures labeled, ventral view. Abbreviations: bc—Bursa copulatrix, pd—Paired spermathecal duct, pds—Paired spermathecal duct stem, ps—Paired spermathecae, sd—Single spermathecal duct, ss—Single spermathecae, vr—Ventral receptacle (...) Abbreviations: ec—Epicephalon, fr—Frontal setae, iv—Inner vertical seta, os—Orbital seta, ov—Outer vertical seta, pc—Paracephalon, po—Postocellar seta, vx—Vertex (…) Abbreviation: s5—Sternite 5.

FIGURES 20–23. Cardiacephala brevipennis. 20, female, lateral view; 21, female genitalia, ventral view; 22, male, dorsolateral view; 23, male Sternite 5 and genitalia, lateral view.

FIGURES 46–49. Cardiacephala lobulosa. 46, female, dorsolateral view; 47, female genitalia, ventral view; 48, male, dorsolateral view; 49, male sternite 5 and genitalia, ventral and lateral view, respectively.

FIGURES 50–52. Cardiacephala modesta. 50, female, dorsolateral view; 51, female genitalia, ventral view; 52, male sternite 5 and genitalia, ventral and lateral view, respectively.