The ventral fusion of the cerci is unusual and although it is known in the Calyptra- tae (McAlpine, 1981) it is rare in Drosophilidae. This character together with the présence of one presutural and three postsutural pairs of dorsocentrals may warrant the création of a new subgenus for this species. In the intérim, and until further spécimens and females are available, S. mateolata, sp. n. is placed in the nominate subgenus. Hackman's (1959) subgeneric description requires no modification to accomodate it. However, it should be noted that in the first couplet of his 1959 subgeneric key, Macroscaptomyza is no longer unique in having four pairs of dorsocentrals.
Etymology. — In caudal view the ventral projection of the epandrium resembles a mace (matea Latin, diminutive : mateola).
Scaptomyza (Scaptomyza) merina, sp. n.
"Scaptomyza sp. 1" of Tsacas et al. (1981 : 218).
Holotype male in MP : "Madagascar Centre, Kimoro 1 680 m, Andringitra Amba- lavao, 19.1.58 B. Stuckenberg", Reg. number 6172. Paratypes (3 males, 9 females) in MP, with same data as holotype and Reg. numbers 6163-6171 and 6173-6175.
Distinguishing Features : Large species ; ocellar setae latéral to anterior ocellus ; with two or three pairs of dorsocentral setae ; scutellar setae approximately subequal ; basai postpronotal setae 0.8 apical; C-index = 3.61; wing hyaline, long and narrow.
Description.
Body length. 2.91 mm (paratype range : males 2.51-3.12; females 2.72-3.04 mm).
Head. Arista with short straight rays, usually two (three in some paratypes) above and one below and a terminal fork. Frons dark brown posteriorly, pale brown anteriorly, reduced to narrow bands between the large ocellar triangle and broad fronto-orbital plates. Ocellar triangle and orbital plates concolorous ; the orbits terminate well before the anterior frontal margin, broaden posteriorly and are slightly raised ; the ocelli are small and colourless and lie on slightly raised integument inside a large silvery-grey, subshining, slightly pollinose triangle; hw:fw = 2.16, fw:fl = 1.12. Vertex rounded. Pedicel tan with two setae as long as dorsal aristal rays ; first flagellomere darker and small. Facial carina prominent, nose-like; face dusky grey-tan medially, paler laterally. Palpus pale tan, with an apical and a shorter subapical seta and small setulae. Gena very broad and short (much of the occiput visible in latéral view), tan, greatest width about a 1/3 greatest diameter of eye (o:j = 3.61, o:ch = 3.47). Vibrissa single, first subvibrissal seta ca 0.6 its length; vibrissal and genal setae subequal. Eye dull, with very dense and long pilosity. Reclinate orbital setae equidistant from eye margin, proclinate orbital medial to anterior reclinate; orbitals in ratio 9:5:10 (orl:or3 = 0.91,orl:or2 = 1.82), orbito-index = 0.62, or3 about halfway between inner vertical seta and anterior frontal margin. Ocellar setae parallel, their bases wide apart and arising latéral to anterior ocellus and in line with posterior ocelli, oc:orl = 1.32; postocellars convergent, poc:oc = 0.82. Inner and outer verticals approximately subequal (or3:iv = 0.72) ; paravertical and anterior reclinate orbital setae subequal.
Thorax. Mesonotum blackish-grey with faint golden pollinosity, scutellum and scutum con- colorous. Acrostichal setulae in four well-defined rows between anterior dorsocentral setae dimi- nishing to two rows posteriorly ; prescutellar acrostichal setulae slightly enlarged. Three pairs of dorsocentral setae, adc barely larger than surrounding acrostichal setulae in holotype but larger in some paratypes e.g., in paratype 6163 adc more than twice as long as acrostichals and in approxi- mate ratio 4:5:9 (adc:mdc:pdc); mdc:pdc of holotype = 0.62. Basai postpronotal seta more than half the length of the apical seta, bpn:apn = 0.8. Basai scutellar setae long and divergent, apicals convergent, bsc:asc = 1.24(pdc:asc = 1.06). Thoracic pleurae and mesonotum concolorous. Halter conspicuous, pale tan. Sterno-index (akpst:pkpst) = 0.54, mkpst:akpst = 0.66 (variable among paratypes). Legs pale tan, paler than body; fore-femur with 6-7 long posteroventral setae and 4-5 posterodorsal setae; each tibia with a subapical seta dorsally, mid-tibia with an apical spur ven- trally.
Wing. Hyaline, long and narrow, veins pale tan. Wing indices, with paratype range between parenthèses : L:w = 2.74(2.58-2.91), C-index = 3.61 (3.28-4.04), 4v-index = 1.68 (1.51-1.71),
Le texte affiché peut comporter un certain nombre d'erreurs. En effet, le mode texte de ce document a été généré de façon automatique par un programme de reconnaissance optique de caractères (OCR). Le taux de reconnaissance estimé pour ce document est de 99.98%.
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