A new species of Dactylonotus Parent (Diptera: Dolichopodidae) from South Africa

Igor Ya. GRICHANOV

Grichanov, I.Ya. A new species of Dactylonotus Parent (Diptera: Dolichopodidae) from South Africa

Dactylonotus meuffelsi sp.n. from South Africa is described. Syntormon formosus Parent from New Zealand is transferred to Dactylonotus. A catalogue and key to 5 known species of the genus are given.

I.Ya. Grichanov, All-Russian Institute of Plant Protection, Podbelskogo 3, St.Petersburg-Pushkin, 189620, Russia.

Key words: Diptera, Dolichopodidae, Dactylonotus, South Africa, new species, new combination, keys.

Introduction

Basing on antennal morphology, Parent (1934) described Dactylonotus within the subfamily Rhaphiinae, relating the genus to Syntormon Loew. The latter genus is included now in the subfamily Sympycninae. Dyte (Dyte and Smith, 1980) left the genus within Rhaphiinae. However, legs setation and hypopygial structures demonstrate strong relationship of Dactylonotus and Argyra. Moreover, Palearctic Argyra elongata (Zetterstedt) also have pedicel with short dorsal projection (Parent, 1938). Some links can be traced between Dactylonotus and Somillus Brethes from South America. The latter genus is included now in Diaphorinae. So, Dactylonotus should be referred to the tribe Argyrini of the subfamily Diaphorinae. Description of Syntormon formosus (Parent, 1933) does not differ from generic diagnosis of Dactylonotus, although investigation of this species for more precise definition of his status is necessary. Four Afrotropical species of the genus are confined to South Africa.

Holotype and paratypes of the new species are deposited in the Natural History Museum in London.

List of known species of Dactylonotus

formosus Parent, 1933:367 (Syntormon), n. comb. - New Zealand

frater Parent, 1938:279 - Southern Africa ["Rhodesia"]

grandicornis Parent, 1934:137 - South Africa

meuffelsi sp. n. - South Africa

rudebecki Vanschuytbroeck, 1960:321 - South Africa

Dactylonotus meuffelsi sp. n.

(Figs. 1, 2)

Holotype. Male, S. Africa (S6), C.P. Silvermine, N.R. Cape penin, 2-3.I.1972 / Southern African Exp. B.M. 1972-1.

Paratypes. 2 females, same labels.

Description. Male. Frons small, grey-brownish pollinose, with medial trapezoid depression, slightly prominent around base of antennae. Face densely whitish pollinose, weakly narrowed in upper part, with parallel sides in lower part, thrice as high as wide at clypeus. Occiput flat, black, grey pollinose. One pair of long ocellar and short postvertical setae; no vertical setae. Postocular setae black in upper part and white in lower part of head. Eyes with short white hairs. Antennae inserted in upper fourth of head, dirty-yellow, brownish dorsally and apically, twice longer than height of head; scape long, bare; pedicel with long, slightly widened at apex, dorso-lateral (interior view) process, covered by dorsal, lateral and ventral setulae; 1st flagellomere very long, widest at apex of pedicel, with acute apex, 4.5 times as long as high in middle, entirely covered by microscopic hairs; arista subapical with microscopic hairs, inserted in distal 1/9 of dorsal side of 1st flagellomere. Length ratio of scape to pedicel to first flagellomere (dorsal to ventral sides) to arista, 25 : 35 : 45: 63 : 30. Palpus and proboscis short, yellow, with sparse black hairs.

Thorax mostly yellow; mesonotum with narrow median metallic blue-green stripe slightly widened posteriad; scutellum dorsally blue-violet with yellow margin; pleura with two small black spots below calypters; thoracic pollination indistinct. Propleura with several light hairs in upper part and 2 strong black-brown setae in lower part. Mesonotum with 1 h, 1 ph, 2 ntpl, 2 ia, 2 sa, 1 pa. Six pairs of dorsocentral setae somewhat decreasing in size anteriorly, with several scattered hairs in front of the 1st one; acrostichals biseriate, increasing in length posteriorly. Scutellum with two long strong setae and two short fine lateral setae, half as long as medians, dorsally bare.

Legs including coxae yellow, apical segments of all tarsi brownish. Fore coxa anteriorly with short black hairs and five or six black lateral and apical setae of various length in one row. Middle coxa anteriorly and apically with black hairs. Middle and hind coxae with black external seta. Fore femora bare; middle and hind femora with one strong subapical anterior setae. Fore tibia with 3 antero-dorsal, 2 posterodorsal setae. Length ratio of fore coxa to femora to tibia to tarsus (segments from first to fifth), 63 : 85 : 99 : 52 : 27 : 19 : 12 : 10. Middle tibia with 3-4 antero-dorsal, 3 postero-dorsal, 1 antero-ventral, 3 or 4 short postero-ventral setae. Length ratio of middle coxa to femora to tibia to tarsus (segments from first to fifth), 57 : 110 : 130 : 66 : 35 : 24 : 17 : 12. Hind tibia with 3 antero-dorsal, 4-5 postero-dorsal, 4 short ventral setae. Length ratio of hind coxa to femora to tibia to tarsus (segments from first to fifth), 45 : 122 : 150 : 40 : 49 : 33 : 20 : 18. All tibiae with strong apical setae; all tarsi simple, with short claws and small pulvilli.

Wing relatively short and narrow, greyish, almost hyaline; veins brown. R1 short, ending at basal 2/5 of wing. Ratio of parts of costa from humeral crossvein to M1+2, 44 : 88 : 23 : 14. R2+3 and R4+5 slightly curved posteriad at extreme apex. M1+2 nearly straight. Crossvein m-cu weakly concave; ratio of m-cu to apical part of CuA1, 17 : 30. Anal vein foldlike; anal angle obtuse. Lower calypter yellow, with black cilia. Haltere yellow.

Abdomen mostly yellow, darkened distad, with black hairs and marginal setae; all segments with narrow dorso-medial brownish stripe becoming dark-brown on last segments; 5th segment mostly brown; 6th segment reduced. Hypopygium brown, with black hairs and 6 macrochetae. Cercus short, yellow, with light hairs. Surstylus yellow-brown.

Female. Similar to male except lacking male secondary sexual characters. Face wide, twice as high as wide. Strong vertical seta present. Antenna longer than head height; 1st flagellomere twice as long as high, with long arista. Length ratio of scape to pedicel to first flagellomere (dorsal to ventral sides) to arista, 15 : 20 : 11: 26 : 62. Proboscis light-brown. short, yellow, with sparse black hairs. Tergum 9+10 with 4 pairs of short thick acanthophorites and long ventral process bearing 2 ventral hairs; cercus short, with rounded apex, bearing several long hairs.

Length: male body without antennae 4.7 mm, female body 5.0 mm, male antenna 1.8 mm, female antenna 1.5, male wing-length 4.7 mm, female wing-length 5.2 mm, male wing-width 1.6 mm, female wing-width 1.8 mm.

Distribution. South Africa.

Etymology. The species is named for Belgian dipterologist, Dr. H.J.G. Meuffels.

Diagnosis. The new species differs from other species of the genus in the longest 1st flagellomere, short subapical arista, normal tarsal pulvilli, and bare femora in male, ratio of length to height of 1st flagellomere in female.

Key to known species of Dactylonotus

Males

1. Arista basodorsal, located near process of pedicel ................ 2

- Arista subapical, located in apical third of dorsal side of 1st flagellomere......................................................3

2. Middle femora with two ventral rows of black setae, nearly as long as femora diameter; tarsal pulvilli normal .......... D. grandicornis

- Middle femora without long setae, anterior and middle tarsi with large pulvilli.........................................D. rudebecki

3. Anterior tarsus with large pulvilli; 1st flagellomere thrice longer than high; arista as long as 1st flagellomere ............. D. frater

- Tarsal pulvilli normal ............................................ 4

4. 1st flagellomere 4.5 times longer than high; arista half as long as 1st flagellomere ................................ D. meuffelsi sp. n.

- 1st flagellomere twice longer than high; arista slightly shorter than 1st flagellomere (New Zealand) ..................... D. formosus

Females

1. Arista subapical, twice longer than 1st flagellomere, which twice longer than high ................................ D. meuffelsi sp. n.

- Arista dorsal, shorter than 1st flagellomere, which thrice longer than high ....................................... D. rudebecki

- Arista basodorsal, 3.5 times longer than 1st flagellomere, which 1.6 longer than high ................................ D. grandicornis

Acknowledgements

I express sincere gratitude to Dr. Brian Pitkin for his kindness in giving me the opportunity to study the collections of the Natural History Museum (London).

References

Dyte C.E. & Smith K.G. 1980. Family Dolichopodidae. In R.W. Crosskey

(ed.). Catalogue of the Diptera of the Afrotropical Region. Brit. Mus.

(Nat. Hist.), London: 443--463.

Parent, 1933:367

Parent O. 1934. Additions a la faune ethiopienne. - Bull. Soc.

Roy. Entomol. d'Egypte, 18: 112-138.

Parent O. 1938. Dipteres Dolichopodidae. Faune de France, 35. Paris: 1--720.

Parent, 1938:279

Vanschuytbroeck P. 1960. Mission zoologique de l'I.R.S.A.C. en

Afrique orientale. L. Diptera Dolichopodidae. - Ann. Mus. roy. Congo

belge, ser 8vo (Zool.), 88, p. 318-321.

[Remarks under figures]

Figs 1--2. Dactylonotus meuffelsi sp.n.

Fig. 1. Hypopygium, lateral view.

Fig. 2. Antenna, midlateral view.

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