Phasioormia bicornis (Malloch)

Nihei, Silvio S., 2015, Systematic revision of the ormiine genera Aulacephala Macquart and Phasioormia Townsend (Diptera, Tachinidae), Zootaxa 3931 (1), pp. 1-26 : 17-19

Phasioormia bicornis (Malloch)

( Figs 21–24 , 39 )

bicornis Malloch, 1932: 313 (Ormia) . Holotype male (BMNH). Type locality: Malaysia, Selangor, Bukit Kitu [Bukit Kutu]. Phasioormia bicornis ; Townsend, 1938: 237 (states that it should be assigned to a new genus); Crosskey, 1976: 64, 185 (combination with Phasioormia , cat.); O’Hara et al. 2009: 161 (cat., China).

Distribution ( Fig. 39 ). China, India (Assam), and Malaysia. Redescription. Male. Body length: 8.0 mm (n=1, holotype), wing length: not measured (both wings damaged at tip).

Coloration: Head dark-brown with silver pruinosity on face, parafacial, fronto-orbital plate, facial ridge, and gena; frontal vitta black. Scape and pedicel yellow, postpedicel blackish, arista brown but light-brown on basal fourth. Palpus yellowish, proboscis light brownish. Thorax reddish-brown but tending to yellowish-brown on postpronotal lobe, notopleuron and lateral parts. Claws light brown with black apex; pulvilli yellow. Abdomen with tergites 1+2 and basal half of 3 light-brown, apical half of tergite 3 and tergite 4 brown, and with whitish pruinosity on tergites 4 and 5.

Head: Frons extremely narrow, on upper 1/3 eyes close to each other and only fronto-orbital plates visible as narrow strips, but frons broadening ventrally. About 12 pairs of frontal setae on lower 2/3, shortening dorsally. Ocellar triangle extremely constricted, but still recognizable, with a few minute setulae, no ocelli. Fronto-orbital plate subequal to pedicel width at lowermost level in frontal view, without setulae. Ratio of frons width/head width at vertex level 0.04; ratio of frons width/head width at level of lunula 0.26. Parafacial bare and as wide as frontoorbital plate. Antenna short; postpedicel about 1.3x pedicel length; arista elongate and slender, about 3.5x length of postpedicel. Antenna inserted at mid height of head in frontal view, and slightly below mid height of eye. Antennal axis/head height ratio 0.51. Antennal axis/vibrissal axis ratio 1.17; antennal axis/oral (epistomal) axis ratio 1.12; vibrissal axis/oral axis ratio 0.96. Genal dilation developed and densely covered with short black setulae. Genal height/head height ratio 0.15. Occiput strongly concave middorsally.

Thorax: Acrostichal setae 0+2, prescutellar pair stronger. Dorsocentral setae 3+3 (anteriormost presutural seta weak). Notopleural setae 2, subequal and close to each other, with few short black setulae. Mesothoracic spiracle conspicuously exposed, with light brownish branched hairs on whole anterior and posterior edges, anterior hairs becoming longer towards upper second quarter, spiracle exposed dorsally and ventrally with just the middle somewhat covered; metathoracic spiracle completely exposed, with very short light brown branched hairs on anterior lappet, and without any hairs or lappet on posterior edge (this was observed on the male holotype and in the female available, and until more material is examined, I am not certain whether this is common to the species or is an artifact of these two specimens).

Wing: Rs node setulose dorsally and ventrally.

Legs: Fore tibia with one differentiated anterodorsal setae at apical third; 2 erect differentiated posterodorsal setae on apical half. Mid femur with 1 basoventral seta. Mid tibia with 1 anterodorsal seta at apical third, and 2 posterodorsal setae on apical half. Hind femur with dorsal and anteroventral rows of setae, and posteroventral row with weak setae. Hind tibia with 2–3 anterodorsal setae on apical half, 2–3 posterodorsal setae on apical half, and 2 anteroventral seta on apical half.

Terminalia: Not dissected, only the male holotype available.

Female. Body length: 8.6 mm (n=1), wing length: 8.0 mm (n=1).

Differs from male by the following: Coloration ( Figs 21–24 ). Head pruinosity grayish on upper portion and tending to pale light-yellow on lower portion ( Figs 23–24 ). Gena and frontal vitta reddish-brown ( Figs 23–24 ). Scape and pedicel yellow, postpedicel entirely orangish, arista yellow ( Figs 23–24 ). Head. Upper ommatidia not enlarged. Frons broad, margins converging from level of antennal insertion towards vertex ( Fig. 23 ), slightly swollen on lower half ( Fig. 24 ). About 16 pairs of frontal setae irregularly sized ( Fig. 23 ), but forming linear row and not strongly developed (the present and observable ones, and based on the insertions of broken setae), with two pairs below level of antennal insertion ( Fig. 24 ). Frontal vitta narrowing towards vertex, about twice pedicel width at lowermost level and subequal to pedicel width at uppermost level ( Fig 23 ). Two pairs of proclinate fronto-orbital setae on upper half, and one reclinate pair before ocellar triangle. Ocellar triangle recognizable, broad and notably protuberant, with dense weak setulae, and bearing no ocelli ( Figs 23–24 ). Fronto-orbital plate broad, about 2.5x pedicel width at lowermost level ( Fig. 23 ). Fronto-orbital plate with weak setulae on its entire length. Ratio of frons width/head width at vertex level 0.30; ratio of frons width/head width at level of lunula 0.37 ( Fig. 23 ). Parafacial bare and narrower than fronto-orbital plate, about 2.0x pedicel width above and narrowing towards gena ( Fig. 23 ). Facial ridge over 2x pedicel width at vibrissal level, with dense fine long setulae on lower portion ( Fig. 23 ). Antennal axis/head height ratio 0.53. Antennal axis/vibrissal axis ratio 1.12; antennal axis/oral (epistomal) axis ratio 1.12; vibrissal axis/oral axis ratio 1.05 ( Fig. 24 ). In profile, anteroventral margin of head (bearing vibrissal, subvibrissal and subcranial setae/setulae) not subparallel to anteroventral margin of eye, closer to eye margin at vibrissal level (anteriorly) and diverging ventrally toward gena (posteriorly), becoming conspicuously distant ( Fig. 24 ). Antenna inserted clearly above mid height of head in frontal view, and slightly above mid height of eye ( Fig. 24 ). Genal height/head height ratio 0.26 ( Fig. 24 ). Genal dilation not apparent; gena covered with short black setulae.

Terminalia: Not dissected, only one female available.

Type material examined. Holotype male ( BMNH), “Holo- / type ” (white round label with red border), “ MALAY PENIN; / Selangor. / Bukit Kitu / at height 3500 ft. / 12-3-1931. / H. M. Pendlebury.”, on the underside of latter label “EX: COLL: / F. M. S. / MUSEUMS.”, white label with underside “Pres. by / Fed. Malay States Mus. / Brit. Mus. 1934-363.”, “ Ormia / bicornis / type / det. JRMALLOCH”. Specimen in good condition, except the wing tips are damaged.

Additional material examined. INDIA, Assam, Gauhati [Guwahati], 1 female, 21.x.1920, B.M. 1924–100, R. Senior-White leg. ( BMNH).

Remarks. This species is extremely poorly represented in collections. If P. pallida is ‘well known’ from a few dozen specimens, P. bi c or n i s was previously known only from the male holotype. I have associated the female from India (Assam) with the type from Malaysia, despite the geographical distance between them, and despite some slight differences noticed between them (see above). I did not find any additional specimens in collections that were visited or contacted, therefore, this is the only known female at present. Nevertheless, Chao & Zhou (2003) extended the distribution of P. bi c or n i s northwards to the Chinese coastal province of Fujian (see also O’Hara et al. 2009). I have not seen this material.

Figures

FIGURE 39. Geographical distribution of the genera Aulacephala (black circles: A. maculithorax; black squares: A. hervei) and Phasioormia (blue circles: P. bi c o r ni s; blue squares: P. pallida; blue stars: P. papuana sp. nov.). [Empty symbols denote inexact locality records, where the country or province capitals were arbitrarily used to plot the occurrence.]

FIGURES 21 – 24. Phasioormia bicornis, female. 21. Dorsal habitus. 22. Lateral habitus. 23. Head, frontal view. 24. Head, lateral view. (Female specimen from India.) (Scale bars 1 mm.)