Sturmiopsis emdeni Mesnil, 1952

Barraclough, D. A., 2004, A taxonomic review of Sturmiopsis Townsend, 1916, an Old World genus of Tachinidae (Diptera) parasitising economically significant lepidopterous stem borers, African Invertebrates 45 (1991), pp. 7-20 : 11-12

Sturmiopsis emdeni Mesnil, 1952

Figs 1 , 6

Sturmiopsis emdeni Mesnil, 1952: 228 ; Herting 1984: 50.

Type material examined: Holotype ^ ( BMNH): ISRAEL: ‘Holo­ / type’ [circular label with red perimeter]; ‘ PALESTINE / J. Palmoni’ [leg glued to card]; ‘TYPE’ [black text on red card]; ‘Pres by / Com Inst Ent / B M 1959–378’; ‘ Sturmiopsis / Emdeni Mesn. / L. Mesnil det, 1950’. In poor condition; thorax extensively ruptured by pin dorsally and laterally; left legs largely detached and right fore leg missing.

Description:

Male:

Dimensions (mm): Body length 5.0; wing length 6.2.

Colour/pollinosity: Head mainly dark brown or black with silver pollinosity; pollinosity noticeably dense on parafrontal and to a lesser extent on parafacial. Ground colour of parafacial, facial ridge and lower extent of face yellow. Antenna with first and second segments yellow­brown and third segment dark brown to black. Gena dark yellow­brown to brown (somewhat paler than lower occiput), indistinctly silver or pale brown pollinose. Palp yellow­brown. Thorax almost entirely dark brown to black, but postalar callus and posterior two­thirds of scutellum yellow­brown; pollinosity almost entirely silver. Legs mostly dark brown to black. Wing completely hyaline, veins yellowish. Abdominal T 1+2 and T 3 mainly blackish, although yellow­brown laterally. T 4 and T 5 dark brown.Abdominal dorsum with silver pollinosity over much of T 3, and on anterior two to three­fifths of T 4 and T 5; posterior sections of T 4 and T 5 golden pollinose.

Head: Outer and inner verticals detached, but outer verticals much weaker than inner verticals; 2 moderately developed reclinate orbital setae (both detached), probably similar in length to inner verticals, inserted just anterior to ocellar triangle. Parafrontal hairing relatively profuse and short, only reaching about one­fifth length of frontal setae. Parafacial hairing noticeably sparser than that on parafrontal and present on upper three to four­fifths of height, hairs absent from anterior and posterior margins. Second antennal segment short, just less than half length of A.s.3. Third aristal segment swollen in about basal one­quarter to half, maximum width usually obviously broader than that of basal aristomeres. Palp only slightly broader apically, apical extremity acutely pointed. Eye completely bare.

Wing ( Fig. 1 ): Margin without subcostal spine. Basal node of R 4+5 with 1–2 setulae. Cell r 5 narrowly open or almost closed at margin, distance along costa at most 0.4 X length of r­m. Bend of M sharply angled, with short appendix, bend positioned relatively distant to wing margin, distance about two­fifths distance from m­cu. Vein m­cu positioned two­thirds distance from r­m to bend of M.

Abdomen: T 3 without median marginal setae. T 4 with complete marginal setal row, this extended ventrally. T 5 with irregular marginal row of setae.

Postabdomen ( Fig. 6 ): Cercus: Modified, dorsally ridged medially, longer than surstylus in profile; hairing on lateral margins distributed on posterior two­fifths, longest hairs at posterior margin, these reaching about half to three­fifths length of entire cercus. Surstylus: Dorsal margin with convex flexure at basal two­fifths in profile; acutely rounded apically, extreme apex relatively sharply pointed. Hairs always present, although not on apical one­fifth, present on apical two to four­fifths; hairing restricted to ventral three­quarters, length of hairs short with longest and strongest hairs distributed along ventral margin, length of these reaching about half depth of surstylus in profile.

Discussion:According to Dr A. Freidberg (pers. comm., 2004), Beth Gordon is a museum that was the former depository of the material examined (listed above), but could also be the locality where the material was collected. The holdings of the museum were all from the Sea of Galilee area. The male is the first known of this little­known species, and is consequently described above. I am convinced—based on venational and colour characters—that it is conspecific with the female holotype.

I can confirm that S. emdeni and S. inferens are distinct species, and they can in fact be relatively easily distinguished (see species key). Of note is the complete lack (even under high magnification) of eye hairing in both sexes of S. emdeni . At least some hairs are typically present in males of S. inferens and S. parasitica (e.g. Fig. 5 ). As only one male of S. emdeni is known, it is impossible to reliably separate it from the other two species using characters of the male postabdomen, given that it is likely to exhibit intraspecific variation in the form and shape of the cercus and surstylus.

Other material examined: ISRAEL: 1 ^, ‘Beth Gordon’, ‘A7068’ ( TAUI); 1 _, ‘A7068’ ( TAUI).

Figures

Figs 1–2. Wing venation (apical two­thirds), showing positions of bend of M and m­cu. 1. Sturmiopsis emdeni. 2. Sturmiopsis parasitica. [Not to scale].

Figs 6–12. Male terminalia in profile (vestiture usually shown on surstylus only) in specimens from selected localities. 6. Sturmiopsis emdeni. 7–12. Sturmiopsis parasitica. 7. Holotype of S. parasitica (Zimbabwe). 8. Cercus and surstylus, holotype of S. angustifrons (Tanzania). 9. Surstylus (Tanzania). 10. Surstylus (Kenya). 11. Surstylus (Nigeria). 12. Surstylus (Ghana). Scale = 1.0 mm.

Fig. 5. Sturmiopsis parasitica; SEM micrograph showing part of male eye in lateral view, with reduced distribution of relatively widely separated, short hairs. [SEM micrograph; scale as indicated]