Craspedochaeta concinna ( Williston, 1896 )

Lonsdale, Owen & Marshall, Stephen A., 2006, Revision of the New World species of Craspedochaeta (Diptera: Clusiidae), Zootaxa 1291 (1), pp. 1-101 : 52-55

Craspedochaeta concinna ( Williston, 1896)

( Figs. 6 , 7 , 81–84 , 106 , Map 11)

Heteroneura concinna Williston, 1896: 387 .

Craspedochaeta atra Kertesz, 1903: 570 . Syn. nov.

Czernyola atra, Melander & Argo, 1924: 25–26 . Hennig, 1938: 131. Syn. nov.

Czernyola minuta Sóos, 1962: 148 . Syn. nov.

Czernyola albohalteria Sóos, 1962: 145–146 . Syn. nov.

Redescription ( Fig. 7 )

Body length 2.3–2.8 mm. Acrostichal bristle sometimes well developed, but usually absent or not much larger than surrounding setulae.

Dark phase: Bristles dark brown to black. Thorax black. Legs dark brown with fore and mid femora yellow to white distally (fore femur entirely dark brown if fore coxa brown) and with tarsi and fore and mid coxae sometimes white; hind coxa sometimes variably brown; occasionally fore and mid legs missing patches of pigment (if so, hind tibia yellow medially and hind femur sometimes yellow, excluding tip). Head mostly yellow; first flagellomere infuscated on anterior 1/ 3 in several Brazilian specimens; posterior 2/3 of frons black (sometimes entirely dark brown); mouthparts usually brown; lower margin of gena, lower 2/3 of face, clypeus, occiput and back of head dark brown to black; gena brown with dorsal margin dirty white and silvery tomentose; parafacial brown and silvery tomentose on inner margin (sometimes white on inner margin). Abdomen dark brown. Wing evenly dusky (excluding costal cell), with base lighter or hyaline.

Pale phase (includes lectotype): As described for dark phase except as follows: bristles yellow; coxae and legs white with mid and hind tibiae browned at ends; hind femur sometimes brown; last tarsomere on hind leg brown; head light yellow to white with frons brown on posterior 2/3 and yellow on anterior 1/3; gena and parafacial silvery tomentose.

Female

Dark phase: Externally as described for male except as follows: pigment much darker; base of hind femur white; mid tibia black; gena black; epiproct and cerci yellow.

Pale phase: Externally as described for male except mid and hind tibiae only brown medially and head more yellow than white. Two specimens from Ecuador much larger (3.4 mm), with hind tibia and first flagellomere brown.

Male terminalia ( Figs. 81–84 )

Annulus well developed. Epandrium as wide as high; length 0.7 times height. Surstylus triangular with tip rounded; twisted so that distal half of inner face visible posteriorly; outer face sparsely setose and inner face heavily setose with several distal tubercules. Cerci 0.6 times length of surstylus and entirely divided; tip of each cercus with one pair of distinctly longer bristles. Pregonite with three strong bristles and several minute setulae. Phallapodeme thin and triangular. Distiphallus very large and sac­like with hook, hair and cone­like protuberances; dark phase with distiphallus smaller and less elaborate, with faint, coiled sclerotization ( Fig. 84 , arrow).

Female terminalia ( Fig. 106 )

Distal 1/3 of spermatheca thin and conical; basal 2/3 cylindrical, tapering basally and annulating medially. Spermathecal duct approximately half length of spermatheca. Ventral receptacle truncate with one pair of wrinkled lateral furrows; tip of ventral receptacle partially recurved with raised sclerotized disc.

Distribution: Argentina, Belize, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, Grenada, Guatemala, Guyana, Honduras, Jamaica, Mexico, Panama, Peru, St. Vincent, Trinidad, Venezuela, United States (FL, NM) (Map 11).

Lectotype ( Heteroneura concinna ): ST. VINCENT. W.I., Leeward side, H.H. Smith (1♂, BMNH).

Holotype ( Czernyola minuta ): COSTA RICA. Higuito, San Mateo, P. Schild (1♂, USNM).

Holotype ( Craspedochaeta albohalteria ): BOLIVIA. Cachuela Esperanza, W.M. Mann, March, Mulford Bio. Expd. 1921–22 (1♂, USNM).

Additional material examined: 348♀♀, 412♂♂ [ BMNH, CASC, CBFC, CNCI, DE BU, EMUS, INBC, INPA, IZAV, QCAZ, ROME, TAMU, USNM, ZSMC] .

Comments: The abdomen is missing from the examined cotype of Heteroneura concinna Williston, 1896 (which we here designate as the lectotype), but the individual is nonetheless clearly conspecific with our specimens of Craspedochaeta atra Kertesz, 1903 . Since Williston’s name has priority over that of Kertesz, C. concinna ( Williston, 1896) is the correct name for this species and for the species group linked to it. We have not been able to locate the three remaining cotypes of C. concinna .

We recognize two distinct colour phases in Craspedochaeta concinna , a light and a dark phase. In Melander & Argo’s (1924) redescription of C. atra , the pale phase was described as the male of the species, and the dark phase as the female, although it was suggested that the two sexes might represent different species. Sóos (1962) later described the pale phase males as C. minuta without reference to Melander & Argo paper, likely not having examined the types of C. atra . It is understandable how the two phases could have been interpreted as different species since they manifest in both sexes (90% of males exhibit the pale phase, and 97% of females exhibit the dark phase) and exhibit numerous differences in both colour and structure.

Despite the differences between colour phases, evidence suggests that they are not distinct species, particularly since a pale phase male has been photographed copulating with a dark phase female (Maquipucuna, Ecuador; Fig. 6 ). The two phases are almost entirely sympatric over a very wide area throughout Central and South America, and while these phenotypes do not always co­occur (pale specimens have been collected in the absence of dark specimens in Grenada, Guatemala, Honduras, Panama, Venezuela, United States (FL), and dark specimens have been collected in the absence of pale specimens in Guyana), the countries where only one or the other phase has been found are generally ones that have been poorly sampled. Craspedochaeta minuta is therefore included here as a junior synonym of C. concinna .

Craspedochaeta albohalteria Sóos, 1962 is also included as a junior synonym of C. concinna , as the holotype shares the phenotype of a very light pale phase male. The first flagellomere of the holotype, however, is much lighter with the outer face entirely yellow. Furthermore, the mouthparts, coxae (excluding the dorsal margin of the mid coxa), fore leg, mid leg, hind femur (excluding a brown apical band) and hind tibia (excluding a brown base and apex) are yellow. While only one female from Costa Rica and one male from Ecuador are as pale as the C. albohalteria holotype, numerous other males from Bolivia and Ecuador exhibit variable combinations of the above characters.

The Florida specimens of Craspedochaeta concinna were collected in Royal Palm Park, Florida (CNCI, USNM) and the New Mexico specimen was collected in “Torrence Co., Menzano Mtns., Tajihue” (CNCI).

We have labeled three males from British Guyana as “ Craspedochaeta cf. concinna ”, because these specimens agree with the description of the pale phase except the frons is dark brown, the pleuron is yellow excluding a brown subnotal stripe and the mid tibia and hind tarsi are pale. The label data for these specimens are as follows: Mazaruni, 2 nd growth (low forest), 25.viii.1937, Richards & Smart (1♂, BMNH), Kaieteur, Savannah & environs., 5.ix.1937, Richards & Smart (2♂♂, BMNH) .

Figures

FIGURE 84: Craspedochaeta concinna (Williston, 1896), dark phase; hypandrial complex, left lateral.

FIGURES 1–6: Figs. 1–5: Craspedochaeta pullipleura spec. nov. males exhibiting agonistic interactions on fallen branch. Fig. 6: C. concinna (Williston, 1896) copulating while the female feeds on dung.

FIGURES 7–9: heads; outline drawing, left lateral (arista and bristles removed, excluding vibrissa and fronto­orbital bristles); 7: Craspedochaeta concinna (Williston, 1896) (C. concinna species group); 8: C. pleuralis (Williston, 1896) (C. transversa species group); 9: C. argoniae spec. nov. (C. biseta species group).

FIGURES 81–83: Craspedochaeta concinna (Williston, 1896); 81: hypandrial complex, left lateral; 82: external male terminalia, left lateral; 83: external male terminalia, posterior.

FIGURES 106–109: Female internal genitalia; 106: Craspedochaeta concinna (Williston, 1896); 107: C. annulipes (Johnson, 1913); 108: C. fascipennis (Melander & Argo, 1924); 109: C. basalis Czerny, 1903.