Melting the iceberg: A new Megaselia Rondani species (Diptera: Phoridae) from Mali with the most striking wing ornament Author Mostovski, Mike B. text African Invertebrates 2015 2015-06-30 56 1 261 261 http://www.bioone.org/doi/10.5733/afin.056.0104 journal article 10.5733/afin.056.0104 2305-2562 C9EF91B7-7FF2-435C-BBDC-DE0A1BE66E6F Megaselia guentermuelleri sp. n. Figs 1–6 ; Table 1 Etymology:The species is dedicated to Dr Günter C. Müller, whose organizational skills and collecting efforts in Mali resulted in the discovery of this remarkable species. Description: Male . Body length : 2.5 mm . Colour : Frons dark brown, antenna brown, palpus pale yellow; scutum and scutellum yellow and slightly ochreous, pleura light yellow except for brown to black posterior part of metapleuron; all legs are yellow except for darkened apex of hind femur; abdominal tergites uniformly brown, abdominal sternites unsclerotised except for S6 represented by paired pigmented patches; epandrium brown, paired hypandrial lobes light brown, anal tube pale yellow. Figs 1, 2. M . guentermuelleri sp. n. , frontal setation (1) and left side of hypopygium (2). Scale bar = 0.1 mm. TABLE 1 Description of Megaselia guentermuelleri sp. n.

Characters	States	Remarks
Head
SA ratio	0.57
ANT (VIF) position	normal
SPS vesicles	absent
Palpal setae length	long	5 long setae + hairs ventrally
Labellum spinosity	sparse	minute hairs
Thorax
Mesopleuron (anepisternum)	bare
Relative halter colour	darker	brown knob
npl setae	2+1	2 bristles and 1 fine hair between them
npl cleft	absent
Scutellar setae	2+2
Leg
ts1 palisade	1–5
tb2 palisade	0.68
tb3 comb bifurcate	absent
tb3 setulae	PD	short, less than tibia width a mid-length
fm3 basal setae	B>AV
fm3 basal setae differentiation	present
Wing
Wing length (mm)	1.90
Wing width (mm)	0.83
Sc	incomplete	very short
Hair at base of R	short	clearly shorter than costal cilia
R2+3	present
Costal index	0.42
Costal ratios (C3=1)	3.8: 2.6: 1
Costal setae length (mm)	0.06–0.08
Alular setae	3
Alular setae length (mm)	0.10
Wing colour	lightly infuscate
Abdomen
T	complete
T setation	normal hairs	on lateral and rear margins, longer on T6
S setation	normal hairs	progressively longer on S3–S6
Spiracles	normal
Genitalia
AT length	AT=E
E setation, left side	hairs + bristles
right side	hairs
Relative posterior setation	T6<E<C<H

Wing : Large heavily pigmented sclerotised bean-like swelling exists below RS at base of 2 nd thin vein, with a paler extension protruding between 2 nd and 3 rd thin veins. Female . Unknown. Comparison: Having a relatively long costa, two strong scutellar bristles, only posterodorsals on the hind tibia and ‘Flügel mit ausgedehneter brauner Makel’, the new species runs immediately to M. leleupi Beyer, 1960 in Beyer’s (1965: 53) key. However, it readily differs from the latter, which has been described from female only, in being larger (2.5 vs 1.8 mm ) and in having yellow pleura (black in M. leleupi ), shorter both costa (CI 0.42 vs 0.53 in M. leleupi ) and costal cilia (0.07 vs 0.16 in M. leleupi ), and different costal ratios (3.8:2.6:1 vs 2.4:2.0: 1 in M. leleupi ). If one ignores this option and proceeds Further with BeYer’s keY, identification oF the specimens on hand becomes confusing. From the Neotropical M. shadeae Hartop & Brown, 2014 with a large, bubbled and pigmented wing spot, the new species easily differs by the position and shape of its wing ornament, shorter costa and narrower RS fork, among other features (cf. Hartop & Brown 2014 ). Figs 3–6. Middle (3) and hind (4) tibiae, hind femur (5) and wing (6) of M . guentermuelleri sp. n. Photographs maY not reflect true colours observed in specimens; bristles oF the tb3 apical comb are enhanced. Scale bars = 0.1 mm. HolotYpe (in ethanol): ♂ MALI : Kéniéroba [ 12°06'26"N 08°19'58"W ], 330 m , 27.vii.2014 , G. Müller & V . Kravchenko , fogging ( TAU ). ParatYpe (dissected, on slide): ♂ same data as For holotYpe , but vii.2014 , sweeping ( TAU ) . Remark: In the absence of corresponding females it would be premature to draw any definite conclusion on the Function oF the wing ornament in this species. Most probablY this is a case oF sexual dimorphism, although some role in the flight aerodYnamics cannot be ruled out completely.