Namibimydas stuckenbergi, Dikow, T., 2012

Dikow, T., 2012, Review of Namibimydas Hesse, 1972 and Nothomydas Hesse, 1969 (Diptera: Mydidae: Syllegomydinae: Halterorchini) with the description of new species, African Invertebrates 53, pp. 79-111 : 92-94

Namibimydas stuckenbergi sp.n.

Figs7-9, 19, 20, 43

ZooBank LSID:see Table1.

Etymology:The species is named after and dedicated to the memory of Diptera systematist and taxonomist Brian Roy Stuckenberg,who contributed in many great ways to Afrotropical dipterology(Kirk-Spriggs2012).

Diagnosis:The species is distinguished from congeners by the long proboscis that extends beyond the fronto-clypeal suture,but does not reach the tip of the postpedicel(Fig.20),the entirely white mystax(Figs19, 20),the long abdominal setation in both males and females,and its apparent distribution in coastal(or near coastal)habitats around Lüderitz in Namibia(Fig.43).

Description:

Male.

Head:Black,in general densely grey pubescent;width distinctly greater than thorax,interocular distance on vertex larger than at ventral eye margin,vertex between compound eyes more-or-less horizontally straight,medially only slightly below dorsal eye margin,parafacial area less than half the width of central facial gibbosity;facial gibbosity distinct,well-developed and discernible in lateral view;mystax white,covering entire facial gibbosity;frons entirely grey pubescent,vertex entirely grey pubescent,postgena lightly grey pubescent;setation:vertex white,frons white,ocp setae white,pocl macrosetae yellow;ocellar triangle apubescent;proboscis brown,long,projecting well-beyond fronto-clypeal suture,reaching half of length of postpedicel;labellum small,as wide as prementum,about quarter length of prementum,unsclerotised laterally;maxillary palpus cylindrical,light brown,as long as pedicel.

Antenna:Brown,scape and pedicel white setose dorsally and ventrally;postpedicel cylindrical in proximal0.4,symmetrically bulbous in distal0.6,≥5.0 × as long as combined length of scape and pedicel;apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax:Brown,predominantly grey pubescent;scutum medially dark brown,laterally brown,surface entirely smooth,lightly grey pubescent,broad sublateral stripes(interrupted postsuturally)and narrow paramedial stripes(not reaching posterior margin)darker grey pubescent,scutal setation comprised of long white setae with distinct rows of long dorsocentral setae and dense lateral scutal setae;dc setae pre- and postsuturally white,acr setae present,lateral scutal setae white,npl setae0,spal setae0,pal setae0;postpronotal lobe brown,grey pubescent;proepisternum,lateral postpronotum,and postpronotal lobe long white setose;scutellum grey pubescent,asetose,apical scutellar setae absent;mesopostnotum,anatergite,and katatergite grey pubescent,mesopostnotum asetose,anatergite asetose,katatergite long white setose;katatergite more-or-less flat;anterior anepisternum asetose,supero-posterior anepisternum long white setose;posterior anepimeron long white setose,katepimeron long white setose;metanepisternum grey pubescent,asetose,metepimeron more-or-less flat,same colour as T1,grey pubescent,long white setose.

Leg:Light brown and brown,setation white setose,brown macrosetose;pro,mes,and met coxa lightly grey pubescent,long white setose;met trochanter setose medially;femur brown,met femur more-or-less cylindrical only slightly wider than pro and mes femur,in distal half macrosetose,1anteroventral and1posteroventral row of macrosetae,posteroventrally long white,erect setose and setae arranged in distinct row;pro,mes,and met tibia straight,met tibia cylindrical,ventral keel absent,lateroposteriorly long white,erect setose and setae arranged in distinct row;pro and mes tarsomere1longer than tarsomere2,but less than combined length of tarsomeres2-3,met tarsomere1as long as combined length of tarsomeres2-3;pulvillus well-developed,as long as well-developed claw,and as wide as base of claw;empodium absent.

Wing:Length 13.2-14.9mm;hyaline throughout,veins light brown,microtrichia absent;cells r1,r4,r5,m3,and cup closed;C terminates at junction with R1;R4terminates in R1;R5terminates in R1;stump vein(R3)at base of R4present,short not reaching R2;R4and R5widest apart medially; r–m distinct,R4+5and M1apart,connected by crossvein;M1straight at r–m (not curving anteriorly),M1(or M1+M2)terminates in R1;CuA1and CuA2split proximally to m–cu (cell m3narrow proximally);M3+CuA1do not terminate together in C;A1undulating,cell a1wide,A1and wing margin further apart proximally than distally;alula well-developed,very large and partly overlapping with scutellum medially;haltere light brown.

Abdomen:Brown;setation comprised of dense long white setose,surface entirely smooth;T1-7brown;T1-7long white setose;T1apubescent,T2-7grey pubescent;S1-7brown;S1asetose,S2-7sparsely white setose;S predominantly apubescent;T2-4parallel-sided and not constricted waist-like;bullae on T2black,transversely elongate,surface entirely smooth,T2surface anterior to bullae smooth.

Terminalia(Figs7-9):Supra-hypandrial sclerite present.

Female.

Wing:Length 12.5-15.2mm.Abdomen:Setation dense short white setose,T1and anterior half of T2long white setose,remaining T short white setose;bullae on T2black,small and circular.Genitalia:9acanthophorite spines per plate.

Holotype:♂ NAMIBIA: Karas: Agate Beach, 10km N Lüderitz, 26°36'22"S 15°10'42"E, 3m,low coastal vegetated dunes, M. and B.Irwin, 18.ii.1974 (AAM-000858, NMSA) .

Paratypes: NAMIBIA: Karas: 2♀ 3♂ Agate Beach, 10km N Lüderitz, 26°36'22"S 15°10'42"E, 3m,low coastal vegetated dunes, M. & B.Irwin, 18.ii.1974 (AAM-000853-AAM-000857, NMSA) ; 1♀ 3♂ Agate Beach, 10km N Lüderitz, 3m,low coastal vegetated dunes, 18.ii.1974, L.Lyneborg (AAM-000861-AAM-000864, ZMUC) .

Other material examined: NAMIBIA: Karas: 1♂ Khoichab Pan , 26°17'58"S 15°32'51"E, 20.i.1966 (AAM-003016, NMNW) ; 1♂ Diaz Point Beach , 26°38'06"S 15°05'27"E,pitfall trap, 13-26.xi.1993, E.Marais (AAM-000885, NMNW) .

Type locality and distribution:Agate Beach(26°36'22"S 15°10'42"E),Namibia(Fig.43,GBIF resource#14003).Biodiversity hotspot:inside and outside of Succulent Karoo.Remarks:The geographic co-ordinates for the Diaz Point Beach specimen in NMNW are given as 26°37'S 15°05'E on the label,but this less-accurate position falls in the Atlantic Ocean north of the actual Diaz Point Beach.