Osmia (Melanosmia) foxi Cameron

Rightmyer, Molly G. & Griswold, Terry, 2010, Description of a new species of Osmia (Hymenoptera: Megachilidae) from southwestern North America, with a redescription of the enigmatic species Osmia foxi Cameron, Zootaxa 2512, pp. 26-46 : 27-33

Osmia (Melanosmia) foxi Cameron

Osmia foxi Cameron 1901: 316

Osmia foxi ; Sandhouse 1939: 138 [unplaced species] ( Figs. 1–19 , 41 )

Diagnosis. — Osmia foxi is distinguished from all other brightly metallic Osmia by the following combination of characters: Females: 1. The margins of the maxillary galea and labial palpi have hairs that are straight; 2. The preoccipital margin is rounded, not abruptly angled; 3. The entire outer surface of the hind tibia is bright metallic green to blue-green, equally as intense as the color found on the mesepisternum; 4. The propodeal triangle is areolate to lineate on its dorsal half or nearly so, with this sculpturing strong and well-spaced ( Fig. 5 ); 5. The scopa is composed of pale golden hairs. Males: 1. The body is relatively large and robust; 2. F11 is slightly expanded apically and its posterior surface is flattened and shining ( Fig. 9 ); 3. The metasomal terga have hairs that are entirely pale; 4. S4 has midapical hairs that are as pale as those found on S2 ( Fig. 12 ); 5. S6 has hairs on the apical margin that are hooked, relatively dense, and stout ( Fig. 15 ).

Description.—Female. Total length: 9.5–10.5 mm; forewing length: 6.4–6.9 mm; ocelloccipital distance: 0.5 mm; ocelorbital distance: 0.5–0.6 mm.

Color: Body brilliant metallic green to blue-green except yellow-green on face (especially paraocular area, interantennal area, and clypeus) ( Figs. 1, 2 ) and brown on mouthparts, labrum, mandible (except basally), apical margin of clypeus, antenna, and tarsal segments distal to basitarsal segments (middle basitarsal segment often also brown). Wings moderately, evenly infuscate.

Pubescence: Clypeus below apical margin with lateral tuft of golden, medially directed hairs. White, minutely branched hairs on mesepisternum, metepisternum, and inner surface of hind tibia; golden, slightly stouter hairs forming scopa and on inner surfaces of legs distal to femora excluding hind tibia; golden to white, minutely branched hairs on remainder of body, usually with longer black hairs intermixed on face (especially mandible, clypeus, and vertex), mesoscutum, and scutellum; forewing membrane covered with brown, short, simple hairs. Galea and basal two labial palpal segments with hairs on lateral margins straight, 0.3–0.5 OD in length. Labrum with long hairs arranged in two curved, transverse rows, along subapical margin and approximately at midpoint, with additional fringe of shorter hairs at apical margin. Clypeus with hairs dense, midapically with hairs bent at apical tips. Hypostomal area with hairs evenly distributed across area, straight to weakly curved medially, 3.0–4.0 OD in length. Mesepisternum with hairs 2.0–3.0 OD in length.

Punctation: Head and mesosoma with punctures nearly contiguous, more or less round, and deeply impressed except as follows: labrum mostly impunctate; clypeus with impunctate midapical truncation about length of F2 or little longer, basally with punctures longitudinally elongate, basolaterally (near anterior tentorial pit) with punctures separated by half puncture diameter; frons with small area on either side of midline anterior to median ocellus with punctures separated by almost one puncture diameter; mesoscutum immediately posterior to median longitudinal sulcus with punctures separated by up to two puncture diameters; tegula with punctures minute, sparse medially and posteriorly, separated by up to four or five puncture diameters; mesepisternum anterior to scrobe and in posteroventral area near midcoxa with punctures separated by half a puncture diameter; metepisternum along anterior margin nearly impunctate; hypostomal area, pronotum, ventral metepisternum, legs, and lateral and posterior surfaces of propodeum with punctures weakly, shallowly impressed; propodeal triangle with dorsal half to third strongly areolate to lineate, lower half to two-thirds weakly shagreened to granulose, dull ( Fig. 5 ). T1 with anterior surface shining, with minute, sparse punctures dorsally; T1–T2 dorsal surfaces excluding apical margins with punctures distinct and wellimpressed, separated by 0.2 to 3.0 puncture diameters; T1–T2 apical impunctate margins relatively narrow (T1 length at midpoint 5.0–6.0 puncture diameters, submedially as narrow as 1.0–2.0 puncture diameters; T2 length 2.0–3.0 puncture diameters, sometimes as narrow as a puncture diameter in places, Fig. 6 ), polished to weakly shagreened. T3–T6 with punctures less distinctly impressed and background integument more strongly shagreened (becoming more strongly so on each successive posterior tergum), with punctures separated by 0.5–3.0 puncture diameters; T3–T5 with apical impunctate margins 2.0–3.0 puncture diameters in length. Mesoscutum medially, mesepisternum anterodorsally, and T1–T3 medially with sparse, minute punctures interspersed between larger punctures.

Structure: Labial palpus four-segmented, second labial palpal segment ca. one-fourth longer than basalmost segment. Maxillary palpus five-segmented. Mandible with outer and condylar ridges of subequal thickness, parallel along length to very weakly converging apically ( Fig. 3 ); apical margin with four teeth, third separated from second and fourth by weak carina, margin of third tooth forming distinct V-shape with adjacent margin of second, margin of third tooth only weakly distinguished from fourth, third tooth slightly directed inwards, not in same plane as other teeth ( Fig. 4 ); inner, ventral margin of mandible lacking distinct tooth, diverging away from condylar ridge basally; mandible apically widened (1.3 times wider than median width), first tooth slightly longer than other teeth, length between apical tips of second and fourth teeth subequal to or slightly wider than apical tips of first and second teeth ( Fig. 4 ). Clypeus with apical truncation distinct from remainder of apical margin laterally (forming 90 degree angle with lateral apical margin of clypeus or nearly so). F1 twice length of F2, remaining apical flagellar segments gradually increasing in length such that F9 subequal to F1, F10 1.3 times length of F1. Vertex behind lateral ocellus 2.5 OD in length. Genal width subequal to that of compound eye in lateral view. Preoccipital margin rounded, not carinate. Hypostomal carina moderately high, gradually tapering to near obsolescence at angle, not forming distinct tooth. Malus forming distinct apical spine. Foretarsal segments excluding basitarsal and apical-most segments with anterior lobes slightly longer than posterior. Mid- and hind tarsal segments with anterior and posterior lobes of equal width, not swollen. Hind tibial spurs curved at apical tips, outer spur more strongly curved and about a fifth shorter than inner. Hind basitarsal segment with lateral margins of outer surface subparallel.

Male. Total length: 10.5 mm (8.5–10.5 mm); forewing length: 7.6 mm (5.8–7.6 mm); ocelloccipital distance: 0.6 mm (0.4–0.6 mm); ocelorbital distance: 0.6 mm (0.4–0.6 mm).

Color: Body brilliant metallic blue to green- or purplish-blue except yellow-green on face (especially paraocular area and interantennal area) ( Figs. 7, 8 ); brown on mouthparts, mandible (except basally), apical margin of clypeus, and antenna excluding scape; brown to metallic blue on labrum, scape, tarsal segments distal to basitarsal segments, and metasomal sterna (especially posterior to S2).

Pubescence: White, minutely branched hairs on body except golden to pale golden, stouter hairs on inner surfaces of tarsi and S4–S6. Labrum with hairs forming transverse, curved row at approximate midpoint, covered with hairs on apical third, forming short fringe at apical margin. S2 with hairs dense at apical margin, slightly longer than those on disc (slightly less than 1.0 OD at apical margin) ( Fig. 12 ). S3 with dense, medially directed hairs filling median third of emargination (hairs ca.0.7 OD in length) ( Fig. 12 ). S4 midapical truncation with sparse, distally hooked hairs arising from papillate bases, interrupted medially by longitudinal impunctate stripe ( Figs. 12 , 13 ). S6 midapical truncation evenly covered with short, stout, distally hooked hairs ( Fig. 15 ).

Punctation: Head and mesosoma with punctures nearly contiguous, more or less round, and deeply impressed except as follows: labrum mostly impunctate on basal half; clypeus with apical margin impunctate, about 0.5 length of F1; mesoscutum immediately posterior to median longitudinal sulcus with punctures separated by up to one, sometimes two puncture diameters; tegula with punctures minute, sparse medially and posteriorly, separated by up to three or four puncture diameters; mesepisternum anterior to scrobe with punctures separated by half a puncture diameter; metepisternum along anterior margin nearly impunctate, on ventral half with punctures separated by one to three puncture diameters; hypostomal area anteriorly, pronotum, legs, and lateral and posterior surfaces of propodeum with punctures weakly, shallowly impressed; propodeal triangle with dorsal half strongly areolate to lineate, lower half weakly shagreened to granulose, dull ( Fig. 10 ). T1 with anterior surface shining, with minute, sparse punctures dorsally; T1–T2 dorsal surfaces excluding apical margins with punctures distinct and well-impressed, separated between 1.0 to 3.0 puncture diameters (denser on T2); apical impunctate margins polished to very weakly shagreened (T1 length 3.0–5.0 puncture diameters; T2 length 4.0–6.0 puncture diameters). T3–T7 with punctures less distinctly impressed and background integument more strongly shagreened (becoming more strongly so on each successive posterior tergum, except T7 relatively polished), with punctures separated by 0.5–2.0 puncture diameters, T3– T5 with apical impunctate margins shagreened, 3.0–6.0 puncture diameters in length, T7 with apical impunctate margin polished, about 4.0 puncture diameters in length. S1 with punctures weakly, shallowly impressed. S2–S3 with punctures minute, distinctly impressed, separated by about a puncture diameter on S2, 0.5 puncture diameter on S3. S4–S6 lacking distinct punctures, S4–S5 with integument shagreened, S6 shining. Mesepisternum anterodorsally and T1–T3 medially with sparse, minute punctures interspersed between larger punctures.

Structure: Mandible with outer and condylar ridges converging apically; apical margin with two teeth, upper tooth distinctly shorter and wider than lower, upper tooth with inner and dorsal margins forming acute to right angle; inner, ventral margin of mandible diverging away from condylar ridge basally. Clypeus more or less evenly convex at apical margin, lacking distinct apical truncation. Flagellar segments subequal in length, with F11 slightly longer than other segments; F10 and especially F11 slightly widened apically ( Fig. 9 ), F11 flattened and shining on posterior surface. Vertex behind lateral ocellus 1.5–2.0 OD in length. Genal width three-fourths (to one-half ventrally) that of compound eye in lateral view. Preoccipital margin rounded, not carinate. Hypostomal carina moderately high, gradually tapering to near obsolescence at angle, not forming distinct tooth. Malus forming distinct apical spine. Foretarsal segments excluding basitarsal and apical-most segments with lobes slightly, equally swollen. Mid- and hind tarsal segments not swollen. Hind tibial spurs curved at apical tips, outer spur more strongly curved and about a fifth shorter than inner. Hind basitarsal segment with lateral margins of outer surface subparallel to slightly diverging apically, lacking tooth on inner margin. T6 midapically weakly emarginate, forming ca. one-fourth of circle in outline; T6 lateroapically with irregular emargination, forming slight process laterally on apical margin ( Fig. 11 ). T7 midapically strongly emarginate, forming semicircle slightly wider than deep (about 1.0 OD deep), with spines on either side of emargination strongly pointed, slightly wider than one-fourth of emargination width ( Fig. 11 ). S2 evenly, strongly convex, covering most of S3. S3 with midapical emargination relatively wide and deep (two-thirds entire width of sternum, 2.5 OD in length) ( Fig. 12 ). S4 midapically with distinct truncation, apical margin of truncation straight to weakly emarginate, width of truncation about half of entire width of sternum ( Figs. 12 , 13 ). S5 with apical margin evenly, weakly convex. S6 with strong midapical truncation, about one-fourth width of sternum, truncation about as wide as deep and weakly rounded apically ( Fig. 15 ). S8 as in Fig. 16 . Gonoforceps weakly tapering apically, weakly recurved at apical tips ( Figs. 14, 17–19 ).

Distribution. — New Mexico and southeastern Arizona, USA and Sonora, Mexico ( Fig. 41 ). Holotype male. —“ Type //B. M. Type Hym. 17a.2521// Osmia Foxi Cam. Type New Mexico // Cameron Coll 1902-105” (LONDON).

Material examined.— MEXICO: SONORA: Agua Prieta, 30 km E, 31˚11’00”N 109˚00’10”W, 8 April 2006, R. Minckley et al. (2Ƥ, ROCHESTER); Agua Prieta, 60 km E, 31˚16’57”N 108˚47’39”W, 8 April 2006, R. Minckley et al. (1Ƥ, ROCHESTER); Alamos, 30 km NE, Rancho Santa Bárbara, 27.12˚N 108.72166˚W, 1334 m, 2 April 2008, M. E. Irwin, F. D. Parker (2Ƥ, LOGAN); USA: ARIZONA: Cochise Co., Portal, 29 March 1964, M. Cazier (13, TEMPE), 21 May 1973 (1Ƥ, TUCSON), Portal, 3 mi W, 10 April 1961, Vicia sp. (1Ƥ, MOSCOW); Southwest Research Station, 5 April 1965, R. B Roberts (333, LOGAN); Pima Co.: Baboquivari Mountains, 19 April 1937, W. Benedict (2Ƥ, 233, LAWRENCE); Baboquivari Mountains, Brown’s Canyon, 17 March 1938 (13, LOS ANGELES); Baboquivari Mts., Elkhorn Ranch, 14 March 1961, Lycium exsertum, J. C. Bequaert (13, TEMPE); Kitt Peak, S slope, Quinlan Mountains, 22 April 1961, M. L. Noller (13, TEMPE); Kitt Peak, 2 mi below summit, Quinlan Mountains, 22 April 1961, J. C. Bequaert (13, TEMPE); Santa Catalina Mountains , 3 April 1953, G. D. Butler (13, TEMPE); Santa Catalina Mountains , mi 5 on Hitchcock Highway, 9 April 1955, Fendlera, Butler, Werner (1Ƥ, 13, TEMPE); Santa Rita Mountains, 30 April 1937, W. Benedict (1Ƥ, LAWRENCE); Tucson, 15 mi NE, 24 April 1966, Torchio, Rust, Yousef (2Ƥ, LOGAN); Santa Cruz Co.: Atascosa Mountains, near Sycamore Canyon, 1400 m, 3 April 1986 (2Ƥ, LOGAN); Oro Blanco, 2 April 1986, R. Griswold (1Ƥ, LOGAN-TLG); Sycamore Canyon, 3 April 1986, R. Griswold (8Ƥ, 433, LOGAN-TLG), T. Griswold (6Ƥ, 13, LOGAN), Lotus tomentellus (10Ƥ, 333, LOGAN); Sycamore Canyon, E of Ruby, 19 March 1986, D. K. Broemeling (2Ƥ, LOGAN), Lotus tomentellus (333, LOGAN).

Comments. —The male holotype of this species was collected in the Santa Fé Mountains of New Mexico, according to Cameron’s (1901) original publication (but not found on the holotype labels). Unfortunately, we have been unable to locate any mountains by this name. It is possible that the recorded locality refers to mountains surrounding the city of Santa Fe; however, this would be a rather large range extension compared to the known distribution of this species.

We have two additional male specimens that appear to be very similar morphologically to O. foxi collected from Sierra Laguna in Baja California Sur in mid-October to mid-December. However, the incongruent flight times and novel ecoregion represented by this locality, as well as lack of female material from this region, make us hesitant to include these specimens among the material represented in the redescription of O. foxi . We tentatively consider these two specimens as a different species closely related to O. foxi and defer the description of them until we have further material.

Figures

FIGURE 41. Distribution of O. foxi Cameron, with circles representing individual collection localities. Hatched areas represent ecoregions to which the collection localities belong: Orange hatched area is the Sierra Madre pine-oak forest ecoregion; blue is the Chihuahuan Desert ecoregion; yellow is the Sonoran Desert ecoregion.

FIGURES 1 – 6. Osmia (Melanosmia) foxi Cameron, female. 1. Dorsal habitus. 2. Face. 3 – 4. Mandible. 3. Outer surface. 4. Apical margin. 5. Propodeal triangle. 6. Apical margin of T 2 and basal area of T 3.

FIGURES 7 – 12. Osmia (Melanosmia) foxi Cameron, male. 7. Dorsal habitus. 8. Face. 9. F 8 – F 11. 10. Propodeal triangle. 11. T 6 and apical margin of T 7. 12. S 2, S 3, and S 4.

FIGURES 13 – 19. Osmia (Melanosmia) foxi Cameron, male. 13. S 4. 14. Genital capsule, dorsal view. 15. S 6. 16. S 8. 17 – 19. Genital capsule. 17. Dorsal view. 18. Ventral view. 19. Lateral view.