Empidideicus rhinoclypeatus Evenhuis

Evenhuis, Neal L., 2007, A remarkable new species of Empidideicus (Diptera: Mythicomyiidae) from Madagascar, Zootaxa 1474, pp. 55-62 : 56-61

Empidideicus rhinoclypeatus Evenhuis , n.sp.

Diagnosis: This new species belongs in the group of species with a closed cell dm ( Anomaloptilus olim). It is easily separated from all Empidideicus by the elongate clypeus, extending below the oral margin and one-half the length of the labrum. The female spermatheca resembles E. insularis Frey (see Greathead, 1986, fig. 3) in 1. Crytoides Engel and Anomaloptilus Hesse were treated as junior synonyms of Empidideicus in Greathead & Evenhuis (2001a) based on characters previously used to distinguish the three that were shown to be variable. Further study has shown that there are additional non-variable characters that appear to confidently distinguish these genus-groups. However, until revisionary work on the genus is completed, it is prudent to leave these as species groupings and to not formally resurrect them from synonymy. [Only undescribed species keying to Cyrtoides olim are known from the regions in this key.]

having basal striations and a hole at the apex or the reservoir but E. insularis has cell dm open apically (closed in E. rhinoclypeatus ). This one of the largest known species in the genus (most are less than 1.0 mm in body length) and is thus easily spotted in collections due to its size.

Description: Male. Length: 1.45–2.38 mm. Wing: 1.50–2.45 mm. Head (Figs. 1–3): longer than high; eyes dichoptic, separated at vertex by 1.5 times distance between lateral ocelli; occiput and postgena black; front slightly depressed medially, white with subrectangular brown area immediately below ocellar tubercle; face white, tip of oral margin tan to brown; antennae dark brown, set in deep pocket; scape short, subtrapezoidal; pedicel subconical, wider than long; first flagellomere lanceolate, length 3.5 times width; second flagellomere one-half length of first flagellomere, with minute transparent apical style; mentum black; clypeus dark brown, elongate, extending well beyond tip of oral margin, length subequal to head height; proboscis dark brown to black, length 2.5 times head length; labrum sclerotized, stiff, pointed apically, length subequal to clypeus; palpus not evident.

FIGURE 1.

Thorax ( Figs. 4–7 , 9–10 ). Mesonotum shiny black with yellow markings in following areas: prescutellar area extending anteriorly for a short distance as traces of admedian vittae; dorsolaterally from humeral callus to transverse suture; post alar callus as anterolateral extension of prescutellar mark; scutellum yellow; mesonotal disc and dorsum of scutellum with short fine brown hairs, small patch of fine minute brown hairs on dorsolateral corner of anepisternum and upper half of propleuron, otherwise, pleura bare; pleura dark brown with pale yellow to white spots on following: posterodorsal corner of anepisternum and anepimeron, laterally on propleuron, upper half of meron; coxae and basal three-fourths of femora and tarsal segments 4 and 5 brown, remainder of legs yellow; halter stem grayish brown, knob white.

Wing ( Fig. 8 ). Elongate, length 3.5 times width; subhyaline with pale brownish tinge; veins brown, well sclerotized except vein separating basal cells and A1; costa ends slightly beyond end of R4+5; vein Sc incomplete; Rs evanescent at connection with R1; R4+5 slightly bowed; vein M1 slightly curved at wing margin; M2 straight; cell dm closed by apical crossvein; A1 effaced, slightly sinuous to wing margin; fringe of hair on posterior margin of wing well shortest at wing tip becoming longer and more sparse toward base.

Abdomen ( Fig. 9 ). Dorsum black, concolorous with central mesonotal color; tergite I white laterally; posterior margins of tergites II-VII and lateral portions white; when viewed laterally abdomen with lateral black band consisting of black color on extreme lateral tips of tergites and sternites; remainder of sternites white; tergites with sparsely scattered minute hairs.

Genitalia ( Fig. 11 : A, B). Hypopygium shiny brown. Gonocoxa subtriangular in lateral view with rounded subrectangular gonostylus; gonocoxal apodemes extending below gonocoxa, flared apically; aedeagal bulb large, rounded; aedeagal apodeme subequal in length to gonocoxal apodeme, peanut-shaped with short lanceolate lateral rami; epiphallus slightly longer than gonocoxa, with hooked apex; epandrium subrectangular with large pointed dorsolateral process.

Female: As in male except dark coloration of thorax and abdomen brown. Abdominal dark coloration interrupted medially by longitudinal white stripe ( Fig. 10 ). Genitalia ( Fig. 12 ): spermatheca spheroid-ellipsoid, sclerotized brown, longer than wide, with striations on basal half, large hole apically; apical spermathecal duct ca. 1.5 x length of spermatheca, thin, transparent; sperm pump 3–4 times length of apical duct, transparent, not sclerotized apically or basally, slightly flared and rounded apically; basal duct confluent with sperm pump.

Types. Holotype ɗ and 43ɗ, 22Ψ paratypes from MADAGASCAR: Tulear Province: Cape Ste Marie Special Reserve, 37 m, 74 km S. of Tsihombe, 25°35.236' S, 45°09.78'E, 5–15 Feb 2003, M. Irwin, F. Parker, Malaise trap, spiny bush. Other paratypes: MADAGASCAR: Tulear Province: 2ɗ, 3Ψ, Mikea Forest, NW of Manombo, 18–29 April 2002, M.E. Irwin, R. Harin’Hala, Malaise trap, deciduous dry forest; 3ɗ, Andohahela National Park, Parcel II, 16–17 Dec 2002, M.E. Irwin, F.D. Parker, R. Harin’Hala, Malaise trap, transitional forest. Holotype in CAS. Paratypes in CAS, MNHN, and BPBM.

Variation. The sexual dimorphism exhibited in this species is most evident in the general brown coloration of the thorax and abdomen in females (black in males) and the female abdomen having the transverse dark bands on the tergites interrupted medially (continuous in males). In addition, there is some variation among specimens in the pattern of the mesonotum. In males the typical form ( Fig. 4 ) is black with has little evidence of admedian vittae or prescutellar yellow marking, this can vary to clearly marked prescutellar yellow marking ( Fig. 5 ) and some specimens showing traces of admedian vittae. In females, the typical form ( Fig. 6 ) has clearly marked admedian vittae as well as distinct yellow prescutellar marking. This can vary to the extreme form of admedian vittae considerably reduced ( Fig. 7 ).

Etymology. The specific epithet derives from Greek, r hi nos = “nose” + cl ypeat us = “provide with a shield”; referring to the elongate clypeus of this new species, which is reminiscent of the nose guards of ancient Greek helmets.

Figures

FIGURES 4 – 7. Empidideicus rhinoclypeatus thoraces, showing differences in mesonotal patterning. 4. Typical male form. 5. Male form with markings. 6. Typical female form. 7. Female form with reduced admedian vittae.

FIGURES 8 – 10. Empidideicus rhinoclypeatus. 8. Wing. 9. Male abdomen showing typical pattern. 10. Female abdomen showing typical pattern.

FIGURES 11 – 12. Empidideicus rhinoclypeatus, genitalia. 11. Male genitalia; A. lateral view. B. Ventral view. 12. Female genitalia with detail of spermathecal reservoir.