Edenophorus Smith, 1969

Sinclair, Bradley J., 2002, Revision of the South African endemic genus Edenophorus Smith (Diptera: Empididae), African Invertebrates 43, pp. 109-122 : 111-113

Edenophorus Smith, 1969

Recognition: Distinguished from other Empididae s.s. by the proboscis positioned anteriorly, palpus straight and not strongly arched, pair of postpronotal setae (one directed anteriorly and other posteriorly), precoxal bridge with lateral setae, R 4+5 unbranched, costa strongly reduced beyond R 4+5, base of phallus with enlarged sperm chamber, and ejaculatory apodeme stout and enlarged.

Description:

Head: Males holoptic with upper facets enlarged, or dichoptic and facets not enlarged. Antenna with scape bearing short setae dorsally; 3-segmented style: segment 8 short, ring-like, segment 9 3–4 times longer than wide, segment 10 peg-like. Proboscis typical of Empidinae : proboscis arising anteriorly near forward margin of head, length subequal to nearly 2 times height of head. Palpus straight, parallel to proboscis; lacinia long and slender, shorter than hypopharnyx. Labrum slender, straight with pair of apical epipharyngeal blades; apex membranous, lacking epipharyngeal brush; epipharyngeal carina short, present at proximal margin. Hypopharynx very stout, straight, parallel to labrum; salivary pump small. Labellum well developed, produced apically; 7–8 pseudotracheae present. Clypeal ridge slender, three-quarters length of cibarium.

Thorax: Acr present, dc uniserial, 2 or more pprn (lower directed forward, upper directed posteriorly); 1 ph (close to postpronotal lobe); 3 npl; 1 pal; 4 sctl.Antepronotum with pair of short setae. Upper half of anepisternum often with numerous setulae; precoxal bridge with 1–2 stout seta above fore coxa; antepronotum with pair of lateral setae, shorter than occipital setae; laterotergite bare. Legs unmodified, lacking sexual modifications.

Wing: Costa strongly reduced beyond R 4+5; Sc incomplete, ending just short of costa; stigma faint, at apex of R 1; R 4+5 unbranched; cell dm complete or crossvein dm-cu absent; if cell dm absent, M vein weakened.

Abdomen: S8 divided into pair of sclerites.

Terminalia: Epandrial lamellae separate, bearing narrow, apical lobe. Cercus thinly sclerotised, not clasper-like. Hypandrium reduced; gonocoxal apodemes broad, expanded horizontally. Postgonite arising from posterolateral margin of hypandrium, secondarily articulated and/or fused to base of phallus. Ejaculatory apodeme broad, strongly sclerotised, articulated to enlarged sclerotised sperm chamber at base of phallus.

Female: Dichoptic.Terminalia: Single spherical spermathecal receptacle present (viewed through cuticle of specimen of E. knysna stored in alcohol, Fig. 1 ).

Remarks: In Smith’s (1969: 129) key to the genera of Southern African Empidinae , Edenophorus will key to the genus Atrichopleura Bezzi on the basis of an unbranched (= unforked) R 4+5 and incomplete Sc. If couplet 5 of his key is replaced by the following modification, Edenophorus can be easily distinguished:

5 Proboscis arising near anterior margin of head ( Fig. 2 ); postpronotal lobe with at least one anteriorly and one posteriorly directed bristle; palpus straight, lying parallel to proboscis ........................................................................... Edenophorus Smith – Proboscis arising near middle of head; postpronotal lobe with several slender setae,

but not distinctly directed anteriorly and posteriorly; palpus strongly arched dorsally,

following the curvature of the lower head margin or gena ................................. 5a

5a Wing vein R 4+5 forked ................................................................ Hilarempis Bezzi – Wing vein R 4+5 unforked ....................................................... Atrichopleura Bezzi

Phylogenetic relationships:

As stated in the Introduction, Edenophorus was originally assigned to the Microphorinae , but at that time male specimens were unknown. The dorsal mesepimeral pocket is present in Edenophorus as described by Ulrich (1994), and it is this feature that provided the first proof that this genus was incorrectly assigned to the Microphorinae (mesepimeral pocket absent in the latter lineage). This pocket is a ground-plan character of the Empididae (s.s.), and also occurs, presumably independently, in the Ceratomerinae and Trichopezinae ( Ulrich 1994; Daugeron 1997; Sinclair & Cumming, unpubl. data).

Further assignment of this genus within the Empidinae remains problematic. The subfamily has traditionally been divided into two tribes, Empidini and Hilarini . However, this is largely based on narrow palearctic concepts, and many southern hemisphere as well as nearctic taxa (e.g., Edenophorus , Empidadelpha Collin , Hesperempis group, and Philetus Melander ) can not be easily inserted into this classification. Consequently, a re-evaluation of the higher classification of the Empidinae is urgently required.

On the basis of an incomplete subcosta (Sc), separate epandrial lamellae, and an upwardly curved phallus, Edenophorus is assigned to a clade including Hemerodromiinae and most Empidinae , (except Philetus and the Hesperempis group) (Sinclair & Cumming, unpubl. data). Based on the costa (C) being strongly reduced beyond R 4+5, Edenophorus appears closely related to the clade comprising Empidadelpha + Empidini + Hilarini (Sinclair & Cumming, unpubl. data). The latter group is characterised by a strongly arched maxillary palpus, which is straight and not curved in Edenophorus .

Figures

Fig. 1. Habitus photograph of Edenophorus kynsna Smith, female (Storms River Village).

Figs 2–7. Edenophorus characters. 2. E. spinosus sp. n., head. 3. E. hiemalis sp. n., antenna. 4. E. knysna Smith, wing. 5. E. hiemalis sp. n., wing. 6–7. E. irwini sp. n., male terminalia. 6. Lateral view. 7. Posterior view. Scale bar = 0.1 mm, except Figs 2, 4, 5, where scale bar = 0.5 mm. [Abbreviations: cerc = cercus; ej apod = ejaculatory apodeme; epand = epandrium; epand lb = epandrial lobe; goncx apod = gonocoxal apodeme; pgt = postgonite; ph = phallus; sp ch = sperm chamber.]