Research Article |
Corresponding author: Christopher J. Borkent ( chris.borkent@gmail.com ) Academic editor: Torsten Dikow
© 2016 Christopher J. Borkent, Jéssica P. Gillung, Shaun L. Winterton.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Borkent CJ, Gillung JP, Winterton SL (2016) Jewelled spider flies of North America: a revision and phylogeny of Eulonchus Gerstaecker (Diptera, Acroceridae). ZooKeys 619: 103-146. https://doi.org/10.3897/zookeys.619.8249
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The spider fly genus Eulonchus Gerstaecker is found throughout the Nearctic Region. Six species are recognized and intraspecific morphological variation is documented in several species. A phylogeny of Eulonchus based on DNA sequence data of three molecular markers (COI, CAD, and 16S) is presented and relationships of species are discussed in the light of biogeography and host usage. All six species of Eulonchus are redescribed using natural language descriptions exported from a character matrix, and a key to species is presented. Lectotypes are designated for E. sapphirinus Osten Sacken, E. smaragdinus Gerstaecker, and E. tristis Loew.
Antrodiaetidae , Euctenizidae , spider parasitoid, phylogeny, small-headed fly, tarantula, biodiversity, cybertaxonomy, Lucid
Acroceridae are a small group of flies commonly known as spider flies or small-headed flies. The family comprises a morphologically heterogeneous assemblage of taxa, with approximately 550 species in 55 genera (
Panopinae (tarantula flies) represent some of the smallest and largest spider flies, with a body size ranging from 4.0 mm (Corononcodes Speiser) to 19.0 mm (Exetasis Walker).
Species of Eulonchus, Lasia and the Australasian genera Apsona and Panops are commonly called ‘jewelled spider flies’, while species of the New World genus Ocnaea are known as ‘hairy tarantula flies’. Lasia and Ocnaea are relatively diverse in the Neotropical Region but are represented in the Nearctic Region only by a few extralimital species. In contrast, Eulonchus is endemic to the Nearctic Region. Six species of Eulonchus are present, distributed from Canada to Mexico. Eulonchus marialiciae Brimley is known only from the eastern USA, while all other species are recorded from the western part of the continent, from Baja California, Mexico, north to British Columbia, Canada, and east to Utah and Arizona. The greatest number of species is known from California, although there are records from Arizona, Idaho, Montana, Nevada, Oregon, Utah, and Washington. Eulonchus marginatus Osten Sacken, E. sapphirinus Osten Sacken, and E. tristis Loew are known from Northern California, the latter two species extending northwards to Oregon, Idaho, Washington and British Columbia. Eulonchus halli Schlinger and E. smaragdinus Gerstaecker are found in California south to Baja California, Mexico.
Eulonchus attack spiders in the families Euctenizidae and Antrodiaetidae (
Several studies also demonstrate the importance of species of Eulonchus as pollinators of several plant families in montane areas of the Nearctic Region, including Boraginaceae, Geraniaceae, Themidaceae, and Iridaceae (
We revise the jewelled spider flies of North America (Eulonchus) and redescribe all valid species using cybertaxonomic methods of natural language description. A molecular phylogeny of the genus is presented along with a discussion of its evolution in a biogeographical context.
Terminology for general morphology follows
Descriptions were constructed with Lucid Builder 3.5, using a matrix database of character states, which were then exported using the natural language function into a text document (for further editing) and accompanying XML. Specimen images were taken using a digital camera at different focal points and combined into a montage image using Helicon Focus software. Distribution maps were generated using ArcGIS 10.1 software (
The specimens examined during the course of this study (Table
Annotations of collection label data are included where appropriate in brackets. The following collection codes are cited in the Material Examined:
Five species of Eulonchus and two outgroup species (Apsona muscaria Westwood and Lasia corvina Erichson (given as L. carbonanicus in
Specimens used for sequencing in this study, with associated Genbank accession numbers. EIS = E.I. Schlinger Collection specimen numbers;
Collection # | Genbank Accession No. | Collection Data | |||
---|---|---|---|---|---|
16S | COI | CAD | |||
Apsona muscaria Westwood | EIS 009956 | AY140851 | — | AF539866 | New Zealand: Otira Valley; January, 1999; LJ Boutin |
Lasia corvina Erichson | EIS 010914 | AY140856 | DQ631969 | AF539865 | Chile: Nuble Prov.: Las Trancas; January, 2000; DK Yeates |
Eulonchus marginatus Osten Sacken | EIS 020189 | KU215393 | KU215390 | — | USA: California: Mendocino County: Angelo Coast Range Reserve; May, 2005; CJ Borkent |
Eulonchus marialiciae Brimley | EIS 009955 | AY140853 | DQ631979 | AF539887 | USA: North Carolina: Great Smoky Mountains N.P.; June, 1999; D Dafoe |
Eulonchus sapphirinus Osten Sacken |
|
AY140852 | — | AF539877 | USA: Washington: South Fork: Wenatachee N.F; July, 2000; KC Holston |
Eulonchus sapphirinus Osten Sacken | CSCA15L303-16V350 | — | KU215391 | — | USA: California: Calaveras County: Calaveras Big Trees State Park; June, 2010; AR Cline |
Eulonchus smaragdinus Gerstaecker |
|
AY140854 | — | AF539867 | USA: California: San Diego County: San Diego; June 2000; SL Winterton |
Eulonchus smaragdinus Gerstaecker | CSCA15L304-16V351 | — | KU215392 | — | USA: California: Alameda County: Pleasanton Ridge Regional Park: June, 2012; JM Ayala |
Eulonchus tristis Loew | CSCA15L302-16V349 | KU215394 | — | — | USA: Oregon: Lane County: Trail Creek; July 2000; JK Moulton |
Eulonchus Gerstaecker, 1856: 359
Eulonchus smaragdinus Gerstaecker, 1856 by monotypy.
North American jewelled spider flies.
Eulonchus can be immediately identified from other Panopinae in the New World by the presence of elongate mouthparts, metallic colouration, and pilose eyes. The only other genus in the New World with metallic colouration is Lasia, which is distinguished from Eulonchus in the eyes being separated below the antennae, and in lacking the palpus and alula. Eulonchus is remarkably similar to the endemic New Zealand genus Apsona and is distinguished from it by the presence of tibial spines (lacking in Apsona), the wing medial veins reaching the wing margin (attenuated in Apsona) and the antennae placed in the middle of the frons (higher in Apsona).
Body length: 7.2–12.8 mm; wing length: 5.2–12.6 mm. Body colouration metallic green, blue or purple, rarely non-metallic (likely due to poor preservation or collection methods). Head hemispherical, width slightly smaller than thorax width; ocellar tubercle slightly to strongly raised, shape variable and either rounded, bifid or trifid, two or three ocelli present; postocular ridge and occiput rounded; eye densely pilose, setae relatively long (2x pedicel length), posterior margin of eye rounded (i.e. not emarginate); antenna located on middle of frons; eye contiguous above and below antennal base; palpus present; proboscis length greater than head length; antennal flagellum elongate, cylindrical to laterally compressed, slightly to strongly tapered apically; in western species male flagellum cylindrical, broader distally, female flagellum more tapered distally; flagellum apex with or without terminal setae; scapes separate (i.e. not fused medially). Thorax with postpronotal lobes not enlarged or contiguous medially; antenotum narrow; subscutellum barely visible beneath scutellum; legs not greatly elongated; tibial spines present apically; pulvilli present; wing hyaline, markings absent; costal vein circumambient around wing, costal margin straight along entire length, rounded apically; humeral crossvein present; vein R1 not inflated distally; R4 and R5 present as forked petiolate veins; radial veins curved towards wing anterior margin; crossvein 2r-m present between M1 and R4+5, bisecting cell r4+5; R4 with or without spur vein; veins M1, M2 and M3 present and reaching wing margin; discal cell closed completely; M4 joining M3, cell m3 petiolate; CuA fused to CuP before wing margin, cell CuA petiolate; wing microtrichia absent; anal lobe well developed; alula weakly developed; abdominal tergites smooth, rounded. Abdomen shape conical to turbinate. Male genitalia (Figs
Eulonchus spp. on various flowers. A, C Male E. tristis Loew on Cryptantha intermedia B Male E. marginatus Osten Sacken trapped on flower of Asclepias sp D, E Male E. tristis approaching and feeding from Iris bracteata F Mated pair of E. tristis on Oxalis oregana G E. smaragdinus Gerstaecker H Three male E. marginatus attempting to mount a single female feeding on thistle I Mated pairs of E. tristis on Penstemon heterophyllus, with one pair resting at length inside the flower. Photo credits: A. Schusteff (D, E, F, I); A. Abela (A, C); G. McDonald (B, H); R. Waayers (G).
Eulonchus halli Schlinger, 1960: 418; Eulonchus marginatus Osten Sacken, 1877: 277; Eulonchus marialiciae Brimley, 1925: 77; Eulonchus sapphirinus Osten Sacken, 1877: 276; Eulonchus smaragdinus Gerstaecker, 1856: 360 (including E. s. smaragdinus Gerstaecker, 1856 and E. s. pilosus Schlinger, 1960); Eulonchus tristis Loew, 1872: 60.
(Fig.
Most species of Eulonchus are relatively widely distributed, and locally abundant, except the sole eastern North American species E. marialiciae. This species is known from only a few specimens, all found within a small contiguous area in the Great Smoky Mountains, with collections from Haywood, Jackson, Macon, Transylvania, and Swain counties in North Carolina. Even though the spider host and floral food source of E. marialiciae are distributed over much of western North Carolina, southwestern Virginia, and eastern Tennessee, the species is only found in five mountainous counties of western North Carolina, at elevations of 1250m or higher. Considering the apparent limited and very isolated distribution of this species, the conservation status of E. marialiciae should be further evaluated. Future studies should focus on identifying potential extralimital populations of this species outside of the presently known distribution, as well as understanding potential biotic (e.g. spider host and plant food source range and distribution) and abiotic (e.g. elevation, climate, vegetation and soil type) factors associated with the apparent limited distribution of this species.
Adult Eulonchus are locally abundant on flowers (
Specimen label and literature records of plants visited by Eulonchus species. The genus has also been recorded visiting flowers of Brassicaceae (Cakile), Fabaceae (Lotus nevadensis), Hydrophyllaceae (Nama parryi), Ranunculaceae (Delphinium, Ranunculus), and Saxifragaceae (Lithophragma).
Plant family | Plant visited | Eulonchus species visiting | |||||
---|---|---|---|---|---|---|---|
E. halli | E. marginatus | E. marialiciae | E. sapphirinus | E. smaragdinus | E. tristis | ||
Asteraceae | Cirsium | X | X | X | |||
Cirsium cymosum | X | ||||||
Erigeron | X | ||||||
Wyethia | X | ||||||
Boraginaceae | Cryptantha intermedia | X | |||||
Eriodictyon californicum | X | X | X | ||||
Hackelia bella | X | ||||||
Hackelia floribunda | X | ||||||
Myosotis | X | ||||||
Myosotis sylvatica | X | ||||||
Phacelia | X | ||||||
Phacelia heterophylla | X | ||||||
Caprifoliaceae | Linnaea borealis | X | |||||
Caryophyllaceae | Stellaria crispa | X | X | ||||
Convolvulaceae | Convolvulus | X | X | ||||
Crassulaceae | Dudleya cultrata | X | |||||
Ericaceae | Azalea occidentalis | X | |||||
Rhododendron | X | ||||||
Rhododendron occidentale | X | ||||||
Vaccinium | X | ||||||
Vaccinium ovatum | X | X | |||||
Gentianaceae | Frasera tubulosa | X | |||||
Geraniaceae | Geranium robertianum | X | |||||
Grossulariaceae | Ribes cereum | X | |||||
Ribes roezlii | X | ||||||
Iridaceae | Iris douglasiana | X | X | X | |||
Iris hartwegii | X | X | |||||
Iridaceae | Iris macrosiphon | X | |||||
Iris purdyi | X | X | |||||
Lamiaceae | Lepechinia calycina | X | |||||
Monardella | X | ||||||
Monardella lanceolata | X | ||||||
Monardella odoratissima | X | ||||||
Salvia carduacea | X | ||||||
Salvia clevelandi | X | ||||||
Liliaceae | Clintonia uniflora | X | X | ||||
Melanthiaceae | Veratrum | X | |||||
Montiaceae | Calyptridium umbellatum | X | |||||
Lewisia cotyledon | X | ||||||
Montia | |||||||
Onagraceae | Clarkia | X | |||||
Clarkia breweri | X | ||||||
Clarkia concinna | X | X | X | ||||
Orchidaceae | Corallorhiza maculata | X | |||||
Oxalidaceae | Oxalis oregana | X | |||||
Papaveraceae | Eschscholzia californica | X | |||||
Phrymaceae | Mimulus aurantiacus | X | X | X | |||
Mimulus glutinosus | X | X | |||||
Mimulus guttatus | X | ||||||
Mimulus longiflorus | X | ||||||
Plantaginaceae | Penstemon | X | X | ||||
Penstemon cardwelli | X | ||||||
Penstemon heterophyllus | X | X | |||||
Veronica americana | X | ||||||
Polemoniaceae | Gilia capitata | X | |||||
Gilia splendens | X | ||||||
Leptosiphon | X | ||||||
Polemoniaceae | Leptosiphon bicolor | X | |||||
Linanthus | X | ||||||
Linanthus androsaceus | X | ||||||
Microsteris gracilis | X | ||||||
Navarretia capitatus | X | ||||||
Polygonaceae | Eriogonum | X | |||||
Primulaceae | Trientalis borealis | X | |||||
Rhamnaceae | Ceanothus cordulatus | X | |||||
Ceanothus integerrimus | X | ||||||
Rosaceae | Chamaebatia foliolosa | X | |||||
Fragaria vesca | X | ||||||
Prunus emarginata | X | ||||||
Rubus | X | ||||||
Rubus canadensis | X | ||||||
Rubus parviflorus | X | ||||||
Rubus ursinus | X | ||||||
Salicaceae | Salix | X | |||||
Themidaceae | Brodiaea | X | X | ||||
Brodiaea bridgesii | X | ||||||
Brodiaea congesta | X | ||||||
Brodiaea elegans | X | X | X | ||||
Brodiaea lutea | X | ||||||
Brodiaea pulchella | X | ||||||
Dichelostomma multiflora | X | ||||||
Triteleia ixioides | X | ||||||
Verbenaceae | Verbena | X |
Species of Eulonchus are very similar to species of Lasia and Apsona, and these three genera, as wells as some species of Panops, are commonly known as jewelled spider flies due to their metallic body colouration. Eulonchus species are commonly called Emeralds or Sapphires, depending on the body colour.
(Fig.
1 | Femora and tibiae completely bright yellow | 2 |
– | Femora completely dark brown, or light to dark brown with dark yellow or cream portion distally; tibiae completely dark brown, or brown with dark yellow to cream basally | 4 |
2 | Flagellum laterally compressed, thicker than scape and pedicel, pendulous, and ~twice length of head; proboscis length rarely extending beyond midpoint of abdomen, typically extending to end of thorax (eastern North America) | E. marialiciae Brimley |
– | Flagellum not laterally compressed, basal portion ~equal to thickness of scape and pedicel, erect, and equal to length of head; proboscis extending beyond midpoint of abdomen, often longer than body (western North America) | 3 |
3 | Proboscis approximately equal to body length, straight; ocellar tubercle typically taller than wide and apex irregularly trifid; median ocellus often weakly developed | E. sapphirinus Osten Sacken |
– | Proboscis distinctly longer than body length, curved at tip; ocellar tubercle wider than tall and apex weakly bifid; median ocellus clearly defined | E. smaragdinus Gerstaecker |
4 | Ocellar tubercle bifid in anterior view; flagellum as long as the head | E. halli Schlinger |
– | Ocellar tubercle trifid; flagellum half as long as the head | 5 |
5 | Margin of calypter light yellow to light brown; femur and tibia light to dark brown with variable amounts of yellow or ivory patterning; pile on the abdomen yellow to light yellow (highly variable species); aedeagus in lateral view with a single rounded point dorsally just before opening of the aedeagus (Fig. |
E. tristis Loew |
– | Margin of calypter dark brown with brown bleeding into calypter membrane; femur completely dark brown, tibia usually dark brown, occasionally with cream yellow on dorsal surface basally (joint between femur and tibia always yellow); pile on abdomen white; aedeagus in lateral view with two rounded points prior to the opening of the aedeagus (Fig. |
E. marginatus Osten Sacken |
Eulonchus halli Schlinger, 1960: 418
Hall’s Sapphire.
Proboscis curved and extending beyond abdomen apex (but shorter than wing length), ocellar tubercle bifurcate; calypter margin pale; legs dark brown-black; abdomen dark brown with reddish metallic hue; extensive white pile on thorax and as bands on abdomen.
Body length: 9.8–12.0 mm, Wing length 8.0–10.6 mm. Head. Flagellum dark brown, scape and pedicel brown; male flagellum cylindrical, shorter than head height; clypeus elongate, extending beyond oral cavity, shape rounded with raised ridge dorsally, surface glossy black-brown with sparse pubescence; labial palp brown, extending anteriorly beyond proboscis at point of attachment; margin of oral cavity (parafacial) finely pubescent, lacking pile; proboscis length extending to middle of abdomen; ocellar tubercle bifurcate, apices narrowly digitate and sub-parallel, tubercle height taller than width, median ocellus greatly reduced; occiput metallic blue or metallic purple, occipital pile densely white. Thorax. Metallic green, metallic blue or metallic purple in colour, setal pile white; coxae black with metallic blue sheen; femora dark brown, apices white; tibia brown; tarsi brown; calypter margin yellow or light brown, membrane translucent; haltere entirely dark brown. Abdomen. Metallic green, metallic blue violet or black with metallic green sheen, vestiture white, dominant setae erect, other pile posteriorly directed, marginal band of denser setae on T3–4. Male genitalia (Figs
Holotype male,
Listed in Table
(Fig.
The larval host for this species is unknown.
Eulonchus halli is a distinctive species that can be distinguished by the dark leg and body colouration, erect white thoracic and abdominal pile, raised bifurcate ocellar tubercle, and a curved proboscis that is shorter than the body length.
Eulonchus marginatus Osten Sacken, 1877: 277
Sombre Sapphire or Emerald.
Proboscis straight, approximately reaching apex of abdomen; ocellar tubercle trifurcate; legs dark brown (pale ‘knee’ joint); calypter margin black or brown.
Body length: 7.2–11.4 mm, wing length: 5.2–9.5 mm. Head. Flagellum dark brown; scape and pedicel brown, male flagellum cylindrical, shorter than head height; clypeus elongate, extending beyond oral cavity, shape rounded with flat area dorsally, clypeus black-brown, glossy with sparse pubescence; labial palp brown, extending anteriorly beyond proboscis at point of attachment; margin of oral cavity (parafacial) pilose, admixed with short pubescence; ocellar tubercle trifurcate, processes narrow (anteromedial process taller), height taller than width; median ocellus greatly reduced or absent; occiput metallic green-blue, metallic blue or metallic purple, pile densely white or yellow. Thorax. Metallic green, blue or purple, setal pile erect, white or yellow; coxae black with metallic blue sheen; femora dark brown, apices white; tibiae brown (whitish basally on dorsal surface); tarsi brown; calypter margin light to dark brown, membrane translucent, with suffused brown marginally; haltere stem dark brown, knob lighter brown. Abdomen. Metallic olive green, green or blue-violet, vestiture white or yellow, dominant setae erect, pile posteriorly directed, marginal band of laterally directed pile on T2–4. Male genitalia. Epandrium round, with posterior margin concave; gonocoxite with anterior margin almost straight, with large fenestrae; aedeagus heavily sclerotized laterally, with a secondary dorsal point just prior to the opening of the aedeagus.
Holotype male,
Listed in Table
(Fig.
Eulonchus marginatus has been recorded visiting the flowers of 10 different plant families and 14 different species (Table
Host unknown.
Eulonchus marginatus is closely related to E. tristis, sharing features such as extensive white thoracic pile and dark colouration on the legs. Eulonchus marginatus is easily distinguished from other species in the genus by the leg colour, trifurcate ocellar tubercle and dark margin of the calypter. This species displays considerable variation in body colour, ranging from metallic green, blue to purple.
Eulonchus marialiciae Brimley, 1925: 77
Mary-Alice’s Emerald.
Antennal flagellum elongate, basally broad and flattened laterally; proboscis straight, relatively short (~half body length); ocellar tubercle trifurcate; legs yellow; calypter margin brown; body colour metallic green.
Body length: 9.9–12.0 mm, Wing length: 9.1–10.2 mm. Head. Flagellum dark brown, male flagellum laterally compressed and variable in amount of distal tapering, longer than head height (pendulous in pinned specimen); scape and pedicel light brown to yellow; clypeus elongate, extending beyond oral cavity, rounded with raised ridge dorsally, surface black-brown, glossy with sparse pubescence; labial palp brown or yellow, length not extending beyond proboscis at point of attachment; margin of oral cavity (parafacial) glabrous or pilose, admixed with pubescence; proboscis straight, shorter than thorax or reaching middle of abdomen; ocellar tubercle trifurcate with processes relatively short and subequal (posterolateral processes often rounded), tubercle height shorter than width; median ocellus present; occiput metallic green-blue or blue, pile densely white or yellow. Thorax. Metallic green, blue or purple, setal pile yellow; coxae black with metallic blue and/or green sheen; femora yellow; tibiae dark yellow; tarsi dark yellow; calypter margin brown, membrane translucent, with suffused brown marginally; haltere stem dark brown, knob lighter brown. Abdomen. Metallic green or blue-violet, vestiture yellow, dominant setae erect. Male genitalia (Figs
Holotype male,
Listed in Table
(Fig.
Flowers visited: Rosaceae: Rubus canadensis L., Rubus sp. (Table
Host: Antrodiaetus unicolor (Antrodiaetidae) (
Eulonchus marialiciae is the only disjunct species in the genus, with a relatively small distribution in the Great Smoky Mountains of North Carolina (USA); all other species are found in contiguous distributions in the far western part of the continent. This species is the sister species to the north-western E. sapphirinus and both have characteristic bright green metallic colouration, short proboscis, yellow legs and similarities in the male genitalia shape. Eulonchus marialiciae has the shortest proboscis of any species in the genus, as well as a much more elongated and laterally compressed flagellum.
Eulonchus sapphirinus Osten Sacken, 1877: 276
Northern Sapphire or Emerald.
Antennal flagellum relatively short, cylindrical or tapered; proboscis straight, shorter than length of body; ocellar tubercle trifurcate; legs yellow; calypter margin pale; body colour metallic green, blue or purple.
Body length: 8.3–11.9 mm, Wing length: 7.1–12.0 mm. Head. Flagellum red-brown or dark brown, male flagellum cylindrical, shorter than head height; scape and pedicel brown; clypeus elongate, extending beyond oral cavity, rounded with flat area dorsally, surface glossy, glabrous, black-brown; labial palp brown, length extending anteriorly beyond proboscis at point of attachment; margin of oral cavity (parafacial) pilose, proboscis length extending to middle of abdomen or equal to abdomen length; ocellar tubercle trifurcate, processes relatively short, subequal (posteromedial processes rounded), height equal to width; median ocellus present, greatly reduced or absent; occiput metallic green-blue, blue or purple, pile densely white or yellow. Thorax. Metallic green, blue or purple, setal pile white or yellow; coxae brown or black with metallic blue (and purple) sheen; femora yellow; tibiae dark yellow; tarsi dark yellow (distal tarsomeres often darker); calypter margin yellow to light brown, membrane transparent or translucent; haltere entirely light brown to yellow. Abdomen. Colour highly variable, metallic olive green, bright green or blue violet, vestiture white or yellow, dominant setae appressed or erect, pile posteriorly directed, marginal band of dense thicker setae on T3–4, or laterally directed pile on T2–4. Male genitalia (Figs
Lectotype male (designated here),
Listed in Table
(Fig.
Eulonchus sapphirinus has been recorded visiting the flowers of 19 different plant families and 30 different species (Table
Host unknown.
Eulonchus sapphirinus is the sister species to the eastern E. marialiciae as both have characteristic bright green metallic colouration, short proboscis, yellow legs and similar shaped male genitalia. The shape of the antennal flagellum and colour of calypter separate the two species.
Eulonchus smaragdinus Gerstaecker, 1856: 360.
Eulonchus smaragdinus pilosus Schlinger, 1960: 418, syn. n.
Southern Emerald or Sapphire.
Proboscis curved and longer than abdomen apex (as long or longer than wing length); ocellar tubercle nearly flat, weakly bifurcated; legs bright yellow; body colour metallic green, blue or purple; thorax covered in yellowish pile.
Body length: 8.3–12.9 mm, Wing length: 6.9–12.6 mm. Head. Flagellum red-brown or dark brown, male flagellum cylindrical, shorter than head height; scape and pedicel brown; clypeus elongate, length equal to oral cavity; rounded with flat area dorsally, black-brown, surface glossy, glabrous; labial palp brown or yellow, extending anteriorly beyond proboscis at point of attachment; margin of oral cavity (parafacial) glabrous, admixed with pubescence; proboscis length extending beyond abdomen; ocellar tubercle bifurcate (processes short and rounded), tubercle height shorter than width; median ocellus present or greatly reduced; occiput metallic green-blue or blue, pile densely white or yellow. Thorax. Metallic green, blue or purple, pile white or yellow; coxae brown or black with metallic blue (and green) sheen; femora yellow; tibiae dark yellow; tarsi dark yellow (distal tarsomeres often darker); calypter margin yellow or light brown; calypter membrane transparent; haltere entirely light brown to yellow. Abdomen. Metallic green or blue-violet, vestiture white or yellow, dominant setae appressed or erect, pile posteriorly directed, marginal band of laterally directed pile on T2–4. Male genitalia (Figs
Lectotype male,
Eulonchus smaragdinus pilosus Schlinger, 1960: 418; Holotype male,
Listed in Table
(Fig.
Eulonchus smaragdinus has been recorded visiting the flowers of 11 different plant families and 18 different species (Table
Host: Aptostichus standfordianus (Euctenizidae) (
Eulonchus smaragdinus is highly variable in size and colour, and is superficially morphologically similar to E. sapphirinus, most notably in the bright yellow legs. However, it can be easily distinguished from the latter in having a proboscis that is curved (rather than straight) that extends beyond the abdomen, and is often longer than body. Male genitalic characters otherwise indicate a closer relationship to E. halli, as suggested by
Eulonchus tristis Loew, 1872: 60.
Dusky Sapphire.
Proboscis reaching apex of abdomen; ocellar tubercle trifurcate with three ocelli present (median smaller than laterals); legs mostly dark brown (‘knee’ pale), calypter margin dark and membrane white or light yellow.
Body length: 7.9–12.8 mm, Wing length: 6.0–11.2 mm. Head. Flagellum dark brown, scape and pedicel brown, male flagellum cylindrical, shorter than head height; clypeus elongate, extending beyond oral cavity, rounded with flat area dorsally, black-brown, surface glossy, glabrous; labial palp brown, length extending anteriorly beyond proboscis at point of attachment; margin of oral cavity (parafacial) pilose admixed with pubescence (faint); proboscis length from middle of abdomen or extending beyond abdomen; ocellar tubercle trifurcate, processes subequal (narrowly digitate), height equal to or shorter than width; median ocellus present, greatly reduced or absent; occiput metallic green-blue, blue or purple, pile densely white or yellow. Thorax. Metallic green, blue or purple, setal pile white or yellow; coxae brown or black with metallic blue sheen; femora dark brown, apicies white; tibiae dark yellow or brown; tarsi dark yellow; calypter margin dark brown or light brown, membrane translucent; haltere entirely dark brown. Abdomen. Metallic olive green, bright green to blue-violet, vestiture white or yellow, dominant setae appressed or erect, pile posteriorly directed, marginal band of dense thicker setae on T3-4, or posteriorly directed, marginal band of laterally directed pile on T2-4. Male genitalia. Epandrium round, with posterior margin almost straight; gonocoxite as tall as wide, with anterior margin almost straight, with large fenestrae; aedeagus heavily sclerotized laterally.
Lectotype male (designated here),
Listed in Table
(Fig.
Pollen loads and diversity from individual E. tristis visiting flowers of Brodiaea elegans (Themidaceae) and Iris douglasiana (Iridaceae) in California has been studied, showing high levels of constancy to a single species (Borkent and Schlinger 2008b). Eulonchus tristis has been recorded visiting the flowers of 19 different plant families and 38 different species (Table
Host: Aliatypus sp. (Antrodiaetidae) (
Eulonchus tristis is most similar to E. marginatus, with which it shares the ocellar tubercle trifid and the flagellum half as long as the head. Eulonchus tristis can be easily distinguished from E. marginatus by its femur and tibia with yellow markings and the pile on abdomen yellow.
Thank you to Philip Perkins (
Table 3
Data type: material examined
Explanation note: Non-type material examined (EIS # = Evert I. Schlinger collection database specimen accession number). See Materials and methods section for notes on depositories.