— PROC. ENTOMOL. SOC. WASH. • 106(4), 2004, pp. 844-850 MAIPOMYIA (DIPTERA: DOLICHOPODIDAE), A NEW GENUS FROM CHILE Daniel Bickel J. Australian Museum, 6 College Street, Sydney, New South Wales 2010, Australia (e-mail: [email protected]) — Abstract. Maipomyia Bickel (Diptera: Dolichopodidae) is newly described from the Central Valley of Chile, and comprises two new species. M. insolita Bickel and M. velata Bickel. Although the genus shares many characters with the subfamily Medeterinae, es- pecially a depressed posterior mesonotum, concave dorsal postcranium, and a life stance on vertical surfaces, other character states suggest it is more isolated. In particular, it has a highly reduced male postabdomen and distinct anterior preapical setae on femora II and III, characters that are not congruent with the traditional concept of the Medeterinae. Key Words: Diptera, Dolichopodidae, Medeterinae, Chile The Chilean Dolichopodidae are best Peiia Museo Entomologico, Universidad de — known from the southern Valdivian forests Chile, Santiago, Chile; (USNM) National (e.g.. Van Duzee 1930, Parent 1932), while Museum of Natural History, Smithsonian the faunas of the central Mediterranean and Institution, Washington, D.C. northern arid regions, by comparison, have The positions of features on elongate been little studied. This paper describes an structures, such as leg segments, are given unusual new genus, Maipomyia, based on as a fractions of the total length, starting specimens collected south of Santiago, cen- from the base. The CuAx ratio is the length tral Chile. The genus comprises two sym- of the m-cu crossvein/distal section CuA. patric species, taken in yellow pan traps and The relative lengths of the podomeres hand-collected off adobe walls. Although should be regarded as representative ratios Maipomyia shares many features with the and not measurements. The ratios for each subfamily Medeterinae, it is unusual in hav- leg are indicated in the following formula ing the hypopygium highly reduced and al- and punctuation: trochanter + femur; tibia; most completely enclosed by the abdomen. tarsomere 1/2/3/4/5. The following ab- This contrasts markedly with the character- breviations and terms are used: I, II, III: istic pedunculate hypopygium of most pro-, meso-, metathoracic legs; C, coxa; T, Medeterinae. tibia; F, femur; ac, acrostichal setae; ad, an- terodorsal; av, anteroventral; dc. dorsocen- Materials and Methods tral setae; dv, dorsoventral; pd, posterodor- sal; pv, posteroventral. This study is based largely on material I collected in Chile, with additional speci- Maipomyia Bickel, new genus mens from CAS. Respositories mentioned in this paper —use the following abbrevia- Etymology. Maipomyia is a combina- tions: (AMS) Australian Museum, Syd- tion of the word "Maipo", from Rio Mai- — ney; (CAS) California Academy of Sci- po, a Chilean river in whose drainage all — ences, San Francisco; (MEUC) Luis E. known specimens were collected, and — — VOLUME NUMBER 106. 4 845 "myia", from the Greek meaning fly. The with the characteristic large pedunculate gender is feminine. hypopygium and bare femora of most Med- Type species. Maipomyia insolita Bick- eterinae. el, new species—. All specimens of Maipomyia were col- Description. Length approximately 2.0 lected within the drainage of the Rio Maipo mm; dorsal postcranium concave; face nar- in the Central Valley of Chile, near the row; first flagellomere rounded; arista api- southern margin of metropolitan Santiago. cal; posterior mesonotum distinctly flat- Although much of the landscape has been tened and slightly depressed; ac short bis- altered by human settlement, the slopes of eriate, or absent; 5 or 6 dc present; 2 proe- the upper valley near San Jose de Maipo pisternal setae present above coxa I; coxa are covered with a dry cactus-thorn scrub, III with single strong lateral seta; femora and Parque Nacional Rio Clarillo preserves slender; FII and Fill each with strong an- a remnant riverine woodland vegetation. terior preapical seta; Til with ad seta at Va, The two included species, Maipomyia in- pd seta at '/;, and ad setae at Vi and %; veins solita and M. velata, are sympatric. They R2+3 and R4+J closely parallel, and both ending before wing apex; vein M distinctly were collected together at Rio Clarillo, both weaker than other veins; vein M curved be- in yellow water traps, and off the white yond m-cu crossvein curved, but without adobe walls of a park building. On the bosse alaire; male abdominal segment 7 walls, individuals were seen to display hidden and not forming peduncle, but with characteristic medeterine behavior, resting well separated bandlike tergum and round- with the head upwards and moving about ed sternum; male sternum 8 covering left the surface in short quick flights, up, down lateral foramen; hypopygium (Figs 2a, d): and laterally. Unlike Medetera, which rests epandrium ovate, with left lateral foramen; with the upper body leaning out. Maipo- hypandrium not evident, but aedeagus elon- myia aligns its body parallel to the vertical gate and with lateral projections as figured; surface. The presence of Maipomyia on surstylus very short and reduced, with some vertical walls suggests it normally occurs long setae; male cercus short and rounded; on tree trunks, like many other medeterines. oviscapt (Figs 2b, c) with tergum 8 forming Maipomyia (Fig. 1) can be separated sclerotised lateral bands which abut fused from all other Dolichopodidae by the fol- terga 9+10; terga 9+10 forming transverse lowing combination of characters: posterior band, divided into hemitergites, and with mesonotum strongly flattened; femora II only short hairs, no strong setae or acan- and III with anterior preapical seta; dorsal thophorites present; sternum 8 forming M postcrainum concave; vein distinctly rounded ventral band. weaker than other veins and gently curved Remarks. Maipomyia comprises two beyond crossvein m-cu; male hypopygium species, M. insolita and M. velata. Al- small, not pedunculate, and enclosed by though the genus shares many characters preceding abdominal segments; upper proe- with the dolichopodid subfamily Medeteri- pisternum with two pale setae. nae, especially a depressed posterior me- sonotum, concave dorsal postcranium, and Maipomyia is distinctive and I have not seen the genus in other Neotropical collec- a characteristic life stance on vertical sur- faces, other character states suggest it is tions. It possibly is confined to the region more isolated. In particular, it has a highly of Mediterranean climate in Central Chile, reduced male postabdomen that is almost and is isolated from the rest of South Amer- completely enclosed by the abdomen, and ica by the high Andes immediately to the distinct anterior preapical setae on femora east, arid deserts to the north, and cool tem- II and III, characters that contrast markedly perate Valdivian rainforests to the south. PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON 846 Fig. 1. Maipomyia insolita, male habitus. VOLUME NUMBER 106, 4 847 Systematic Position of Maipomyia plesiomorphic with respect to the medeterine groundplan. What are the phylogenetic relationships M 3. distinctly weaker than other veins. of Maipomyial Apart from the highly re- In most dolichopodid genera the ma- duced male hypopygium and the anterior jor longitudinal veins of the wing are preapical setae on femora I and II, the ge- more or less subequal in thickness. nus appears to be closest to the subfamily M This weak vein is probably an au- Medeterinae. However, the limits of this tapomorphy for Maipomyia. subfamily are uncertain, and much more ba- 4. Male abdominal segment 7 hidden sic systematic investigation is needed be- and not forming peduncle, but with fore any meaningful phylogenetic analysis well separated band-like tergum and can be undertaken (also see Bickel 1986). rounded sternum (Fig. 2d). In all oth- However, the character states ofMaipomyia er Medeterinae, the hypopygial pe- are discussed below and related to those of duncle formed from segment 7 is the type genus, Medetera Fisher von Wald- prolonged, often greatly so, with the heim. tergum and sternum often partially fused. The unfused non-pedunculate Characters shared by Maipomyia and I. condition of segment 7 in Maipo- Medetera (not necessarily derived) myia is plesiomorphic with respect to 1. First flagellomere subrectangular to most Medeterinae. subovate, with apical arista. 5. Hypandrium not evident and possi- 2. Dorsal postcranium concave. bly fused with the epandrium. This 3. Face width subequal in both sexes, is an autapomorphy, as the hypan- and parallel sided or slightly con- drium is present in most Dolichopod- verging ventrally. idae. 4. Posterior mesonotum strongly flat- 6. Surstylus only very short, conform- tened and slightly depressed. ing to curvature of epandrium. This 5. Lateral scutellar setae reduced to tiny is an autapomorphy, as most Doli- setae or absent. chopodidae have arm-like surstyli. 6. Legs usually without strong male 7. Oviscapt (Figs 2b, c) with tergum 8 secondary sexual characters. forming sclerotised lateral bands 7. Leg I without major setae. which abut fused terga 9+10; terga M 8. Vein without bosse alaire, the 9+10 forming transverse band, di- flexion and slight wing indentation vided medially into hemitergites, but found in some dolichopodids. with only short vestiture, no strong 9. Hypopygial foramen left lateral. setae or acanthophorites present. II. Characters diagnostic for Maipomyia This oviscapt structure is possibly 1. Proeipsternum with two setae. Most unique in the family, and is an au- Medeterinae have a bare proepister- tapomorphy for the genus. Most Dol- num, except for Systenus Loew, ichopodidae have terga 9+10 divid- which has a single proepisternal seta. ed into hemitergites, which bear 2. Femora II and III each with strong strong setae or acanthophorites. anterior preapical seta. All Medeter- Key to Species of Maipomyia inae have the femora bare of anterior preapical setae, a key defining char- Ac absent; 5 strong dc present: ventralmost How- postorbital seta greatly prolonged and curved acter state for the subfamily. (Fig. 1); wing length < 2.1 mm; hypopygium ever, anterior femoral preapical setae (Fig. 2a) (Chile) '. . M. insolita are widespread in other dolichopodid Ac short biseriate; 6 strong dc present; ven- taxa and their presence is possibly tralmost postorbital seta not greatly prolonged; 848 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON tg9+io Fig. 2. Moipomyia insolita. a, Hypopygium. left lateral, b. Female oviscapt, left lateral, c. Female oviscapt, dorsal. M. velata. d, Male postabdomen; left lateral. Legend: aed, aedeagus; cer, cercus; sur, surstylus; tg, tergum; St, sternum. Scale line = 0.1 mm. wing length > 2.2 mm; hypopygium (Fig. 2d) 2.i. 1997, collected off white adobe walls (Chile) M. velata (AMS). — Maipomyia insolita Bickel, new species Description. Male: 1.8 mm; Wing: 2.0 (Figs. 1, 2a—c) X 0.8 mm; habitus (Fig. 1). — Head: Dorsal postcranium concave; Type material. Holotype, d, Paratypes, frons black, covered with grey pruinosity; 4 d, 8 9, CHILE: nr. San Jose de Maipo, setae brown with yellowish reflections; 33°25'S 70°23'W, 2-3.i.l997, 1050 m, cac- strong vertical and ocellar setae present; tus/thorn scrub, yellow water traps, D. J. face narrow and slightly converging ven- Bickel (Holotype, 6 , paratype 9 , deposited trally; palp brown, ovate, with short hairs; MEUC; 3 d, 7 9 paratypes deposited proboscis brown; scape and pedicel yellow- USNM). ish, but infuscated in some specimens; first Additional material.—CHILE: 2 c5, 4 9, flagellomere black, rounded; arista apical, PN Rio Clarillo, 33°29'S 70°29'W, 2- and slightly longer than head height; post- 3.i.1997, 870 m. dry riverine forest, yellow orbital setae white, longer on ventral third, water traps, D. J. Bickel; 4 9, same but with ventralmost seta long and curved. VOLUME NUMBER 106, 4 849 Thorax: Mostly black, covered with grey and covering foramen; hypopygium (Fig. pruinosity; scutellum black basally with a 2a) dark brown with yellowish cercus; distinct wide yellow rim; posterior meson- epandrium ovate, with large left lateral fo- otum distinctly flattened and slightly de- ramen; hypandrium not evident; aedeagus pressed; setae yellowish; ac absent; 5 strong with lateral projections as figured; surstylus dc present which decrease in size anteriorly; very short and with some long setae; cercus 1 posterior supra-alar seta, 2 postalar setae, short and rounded, with short setae. 1 postpronotal seta, and 2 notopleural setae; Female: Similar except as noted: no 2 proepisternal setae above coxa I, ventral strong secondary sexual differences evi- seta about twice length of dorsal; scutellum dent; podomere ratios similar; ventralmost with strong median and tiny weak lateral postorbital seta also long and curved; ovis- setae; postnotum broad and slightly bulg- capt (Figs. 2b, c) with tergum 8 forming ing. well-sclerotised lateral bands which abut Legs: CI yellow; CII and CIII yellowish fused terga 9+10; sternum 8 forming with some infuscation; remainder of legs rounded ventral band; terga 9+10 forming mostly yellow; with distal tarsomeres transverse band, divided medially into hem- slightly infuscated; major setae yellow; CI itergites, but with only short hairs, no with 6-7 lateral setae; CII with some short strong setae or acanthophorites present. — distolateral setae; CIII with single strong Remarks. The specific epithet, insolita, lateral seta; femora slender; I: 3.0; 2.5; 1.2/ is from the Latin for "isolated", referring 0.8/ 0.6/ 0.4/ 0.3; leg I without major setae; to the fact that Maipomyia is morphologi- II: 3.5; 3.5; 1.4/ 0.8/ 0.6/ 0.4/ 0.3; FII with cally distinct or isolated from other doli- strong anterior preapical seta; Til with ad chopodid genera. For further notes, see seta at Vi and %, pd seta at '/g, and apically "Remarks" under the generic discussion. with anterior, ad and ventral setae; tarsi bare; III: 3.8; 4.0; 0.7/ 1.2/ 0.6/ 0.5/ 0.3; Maipomyia velata Bickel, new species Fill with anterior preapical seta; Till with (Fig. 2d) some dorsal setae but no major ad or pd — Type material. Holotype, S, Paratypes, setae, and apically with dorsal, av and ven- 2 9, CHILE: PN Rio Clarillo. 33°29'S tral setae. Wing: Hyaline and relatively broad; R2+3 70°29'W, 2.i.l997, 870 m, dry riverine for- and R4+5 closely parallel and both ending est, collected off white adobe walls D. J. well before wing apex; costa weakened be- Bickel; Paratype, 6. same but 2-3.1.1997, yond R4+3 before ending at apex; vein M in yellow water traps (Holotype, d, Para- MEUC; with gentle curve beyond m-cu crossvein. type 9, deposited 6, 9 paratypes distinctly weaker than R.+3 and R4+, and deposited USNM). ending at apex; CuAx ratio: 0.8; anal vein Additional material.—CHILE: 2 6.2 9, weak; halter yellow; lower calypter yellow Santiago Prov., Quebrada de la Plata, with fan of yellow setae. 33°30'S 70°55'W, nr Malpii, 2.ii.I966, 510 Abdomen: Terga brown with some metallic m, malaise trap—, M.E. Irwin (CAS). green reflections, and covered with grey Description. Male: 2.2 mm; Wing: 2.3 pruinosity; terga 1-5 with long yellowish X 0.8 mm; similar to M. insolita except as marginal setae, longer laterally; terga 2-5 noted: each with 3-4 lateral abdominal plaques; Head: Without long ventralmost postor- abdominal sterna 2-5 brown; tergum 6 yel- bital seta. low, contrasting with preceding dark brown Thorax: Setae yellow; ac biseriate, with segments; segment 7 hidden and not form- 5-6 short pairs; 6 strong dc present which ing peduncle, with band-like tergum and decrease in size anteriorly. rounded sternum; sternum 8 dark brown Legs: Color similar but coxae II and III 850 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON more yellow; setation and podomere ratios CONAF, Corporacion Nacional Forestal, similar. Puerto Montt, gave permission to collect in Abdomen: Color similar, except segment reserves under their administration. R. Hur- 6 brown; hypopygium (Fig. 2d); surstylus ley and S. Brooks provided helpful com- with longer setae, and with lobate dorsal ments on a draft manuscript of this paper. projection; cercus also short and rounded, with somewhat longer setae. Literature Cited Female: Similar to male. — Remarks. The specific epithet, velata, Bickel, D. J. 1986. Thrypticus and an allied new genus, is from the Latin for "hidden", referring to Corindia, from Australia (Diptera: Dolichopodi- dae). Records of the Australian Museum 38: 135- the fact I did not initially recognise it as a 151. species distinct from M. insolita. For fur- Parent, O. 1932. Especes nouvelles du genre Sympyc- ther notes, see "Remarks" under the ge- niis Lw. provenant de I'Amerique du sud et con- neric discussion. servee au Museum de Dresde. Encyclopedic En- Acknowledgments tomologique (B, II) Diptera, 6: 41-70. Van Duzee, M. C. 1930. Dolichopodidae, Part 5(1): 1- H. Finlay drew the figures. I thank K. 92. In Diptera of Patagonia and South Chile. Brit- Ribardo (CAS) for the loan of specimens. ish Museum (Natural History), London.