Litometopa
Nothing is known about the biology of Litometopa species. Most specimens were swept with a net from flowers, savanna trees and bushes, and some specimens were sampled by canopy fogging.
Head: About as long or longer than high, black, only base of arista and often base of palpus yellowish, polished except for microtrichose antenna, fovea, and ventral facial margin. Frons glabrous, polished, 1.3-2.0x as long as broad (length measured from ptilinal fissure to base of postocellar setae; breadth measured at narrowest point between eye margins). Frontal width nearly equal in male and female; lacking interfrontal stripes or setulae, except pair of setulae anteriorly. Frontal triangle small, not extended beyond ocelli. One reclinate and slightly lateroclinate orbital seta and 2 medioclinate frontal setae. Two proclinate setulae between orbital seta and posterior frontal seta, anterior seta slightly larger than posterior one, possibly representing reduced anterior orbital seta. One medioclinate setula present close and anterior to posterior frontal seta, and one medioclinate setula present anterior to anterior frontal seta. Lateroproclinate ocellar and medial and lateral vertical setae present. Postocellar setae parallel to slightly convergent. Lunule visible, extended to basal part of first flagellomere, triangular, pointed, with pair of setulae. Face concave, antenna short, first flagellomere round; arista long, slender, microscopically pubescent. Vibrissal angle produced, usually half as broad as first flagellomere, but sometimes equibroad or broader (vibrissal angle measured from anteriormost point of eye margin to anterior tip of vibrissal angle), vibrissa well developed. Gena about 0.1-0.2x as high as eye. Postorbital region (i.e., space between eye and postocular setulae) in male 2-3x longer than in female, up to about a third as long as eye (length of eye measured as horizontal line between anteriormost and posteriormost points of eye; length of postorbital region measured at posteriormost point of eye). Palpus flat, elongate spatulate to rather broad, with small setulae and two longer setae at anterolateral edge; in male entirely microtrichose, in female ventrally glabrous and shiny. Clypeolabral membrane at base of palpus slightly sclerotized. Prementum broader and thicker than combined labella, which have four pseudotracheae each. In female, pseudotracheal teeth on medial pseudotrachea extremely long and thin, bent to about 90°, and with small subsidiary tooth at angle. Small subsidiary teeth also present on teeth of other pseudotracheae. In male, teeth on all pseudotracheae about equally long and neither bent nor toothed.
Thorax: Black, narrow and elongate. Mesonotum 1.5-2.0X as long as broad, finely shagreened, subshiny, almost bare of setulae, with only dorsocentral row of setulae and median (unpaired) acrostichal row, that becomes 2 irregular rows posteriorly, and few scattered setulae laterally. Anepisternum and furcasternum elongate and fused. Basisternum with precoxal bridge, similar to variant "Q/T" of Speight (1969). Pleura strongly shiny, though in part somewhat rugose, anepimeron and katepisternum posteriorly and meron, katatergite and anatergite entirely dull, gray microtrichose. Scutellum shiny, glabrous. Chaetotaxy: 1 long postpronotal seta and 2 postpronotal setulae, of which one may be longer and directed dorsad, 2 notopleural setae, 1 presutural represented by setula, 1 short supraalar, 1 long postalar, 1 short intraalar, 2 dorsocentral setae, anterior one about half length of posterior one, and row of dorsocentral setulae progressively shortened anteriorly. 1 apical and 1 basal scutellar setae, basal seta 1/2 as long as apical seta, anepisternum bare, 1 katepisternal and no anepimeral seta.
Legs: Foreleg large, appearing raptorial, with elongate coxa and often incrassate femur with anteroventral and posteroventral rows of 6-8 strong spines each. Forecoxa bright yellow, and foretibia and foretarsus black in all studied species, whereas forefemur varies between species, from predominantly black to almost entirely yellow. Foreleg appears thicker due to brush of black setulae ventrally at distal end of tibia and on tarsus. Mid- and hindlegs more or less normal. Mid- and hindtibiae and midand hindtarsi except distal tarsomeres yellow. Basal two tarsomeres of hindleg with posteroventral brush of either pale (yellow) or dark (brown or black) setulae. Pale setulae more coarsly and more spirally fluted than normal black setulae in D. brachycephala. Structure of setulae in brush not studied in other species.
Wing; Hyaline. R4+5 and M1+2 very slightly convergent. Last section of M1+2 about 2.75x as long as penultimate section. Cell cup closed, but only weakly differentiated.
Abdomen: Black, slender and elongate. Male usually with paired sclerotized internal saclike structures (see next section).
Male terminalia similar to those of other Desmometopa species. Cercus as large as epandrium in lateral view; 2-4 long setae laterally on epandrium, number sometimes varying between sides. Surstylus partly fused to epandrium, covered by setulae medially, similar to flame of candle in ventral view. Pregonite with 2 setulae distally. Distiphallus forming long membranous tube, which is widened in middle, dorsobasally with sclerotized strip.
Female with tergite and sternite 6 and 7 not reduced in size (reduced in many other Milichiidae). Lateral margins of sternite 7 and tergite 7 overlapping. Sternite
6 anteromedially with small pointed process. Segment 7 internally with secondary ovipositor (Brake 2000; and see next section). Female internal reproductive system without any sclerotized structures. Spermathecal ducts elongated and loosely (i.e., the ducts are not lying directly next to each other) rolled together distally into one small coil. Spermathecal duct basally wider and possibly surrounded by muscles. Duct and surrounding epithelium in coil narrower. No sclerotized spermathecal capsule. Distal end of spermathecal duct projecting out of coil and surrounded by epithelial gland cells. Tip of duct slightly enlarged (see fig. 24H, D. sabroskyi, in Brake 2000). Peculiarities of the male and female genitalia.
Males of Litometopa usually have peculiar paired structures within the fifth abdominal segment. Each structure consists of two sclerotized reservoirs, which are surrounded by tissue. The reservoirs are elongate sacs connected by ducts, which are sclerotized in the same manner. The duct leading to the anterior reservoir is longer than the one leading to the posterior reservoir. The ducts lie dorsally, but the sacs are directed ventrad. Near the terminalia, the ducts of both reservoirs meet and fuse to form a common duct. The common ducts of either side open close to each other dorsally between the fifth tergite and the terminalia. On each common duct there is a spiracle, probably spiracle 7. A second spiracle lies in the membrane between the duct opening and the fifth tergite. This is probably the spiracle 6. There does not seem to be a valve for the reservoirs. The sclerotized wall of the reservoirs is covered by slight, longish indentations, similar to the surface of a golfball. A few short setulalike structures are on these indentations towards the lumen of the reservoir. It is possible that each of these structures represents a connection between the surrounding tissue and the reservoir. However, in SEM dissections no holes in the tip of the setulalike structures could be discerned. The reservoirs in all dissected specimens (both dry and alcohol-preserved material) seemed to be empty. We suppose that this structure represents a gland, based on the tissue surrounding the reservoirs and on the setulalike structures in the reservoirs. We will use the term "abdominal reservoirs" for this structure. The abdominal reservoirs possibly evolved from synsternite 7/8, which is absent in Litometopa* because the 6th and 7th spiracle are often in synsternite 7/8 in Milichiidae and especially in Desmometopa.
In females there is a specialized structure inside segment 7, which is called a secondary ovipositor and is used for oviposition (Brake 2000). Presumably, while ovipositing, the secondary ovipositor is everted telescopelike between sternite 7 and the subanal plate. Basally the structure consists of a broad membranous ring with many anteriorly directed barbed spines. Distally there are two weakly sclerotized strips each with a row of yellow setulae. These strips originate ventrolaterally and meet dorsally at the functional tip of the ovipositor. Between these strips, which represent sternite 8, lies the genital opening. When the secondary ovipositor is retracted, only the basal part is turned over, with the barbed spines now directed posteriorly. In addition to the secondary ovipositor, Litometopa is characterised by a very small tergite 8, a bare supra-anal plate and short, round cerci. This combination of characters is not restricted to the subgenus Litometopa, but is found in Desmometopa species and in Pholeomyia and is therefore probably plesiomorphic. (Brake & Freidberg 2003)
Afrotropical: Ethiopia, Kenya, Tanzania, Uganda, Rwanda, Congo, Nigeria, and South Africa. This apparently disjunct pattern indicates a possibly wider and more homogenous distribution in the Afrotropical Region.