Osmia (Diceratosmia) conjuncta Cresson, 1864

Rightmyer, Molly G., 2017, A revision of the subgenus Osmia (Diceratosmia), with descriptions of four new species (Hymenoptera, Megachilidae), Zootaxa 4337 (1), pp. 1-37 : 6-7

Osmia (Diceratosmia) conjuncta Cresson

( Figs 2D , 7B , 8C )

Osmia conjuncta Cresson 1864: 31 –32 [Holotype female: Philadelphia]; Medler & Lussenhop 1968: 42 –43 [diagnosis of male].

Osmia 4-dentata Cresson 1878: 107 [Holotype male: Philadelphia]; (preoccupied); Robertson 1893: 276 [synonymy].

Osmia cressonii Dalla Torre 1896: 392 [replacement name for quadridentata Cresson , nec quadridentata Fonscolombe 1879 , which is a junior synonym of Hoplitis (Anthocopa) jakovlevi (Radoskowski) , Zanden 1996: 885]

Osmia quadridentata Cresson ; Dalla Torre 1896: 392 [Emend.]; Cockerell 1912: 223 [synonymy].

Diceratosmia quadridentata (Cresson) ; Robertson 1903: 171.

Diceratosmia conjuncta (Cresson) ; Sandhouse 1939: 139.

Osmia (Diceratosmia) conjuncta Cresson ; Sinha 1958: 230.

Diagnosis. Females of O. conjuncta can be distinguished from all other small (i.e., intertegular distance 1.5–2.5 mm), blue Diceratosmia except O. marilaunidii by the combination of lack of modified facial and scopal hairs, shiny clypeus and frons, and the smoothly rounded mesepisternum between the anterior and lateral surfaces. Females of O. conjuncta can be distinguished from O. marilaunidii by the relatively straight carina between the second and fourth mandibular teeth in O. conjuncta (forming at most one-fourth of a circle) versus more strongly semicircular in O. marilaunidii (forming ca. one-half of a circle), as well as by the sculpturing of the anterior surface of T1 (dull in O. conjuncta , polished in O. marilaunidii ).

Males of O. conjuncta can be distinguished from all other blue/green Diceratosmia except O. marilaunidii by the strongly concave apical margin of S3; the acutely pointed lateral projections of T6; and the long, slender medioapical hairs on S4 that are well separated from the hairs on the far lateral sides of S4. Osmia conjuncta and O. marilaunidii can be separated by the dull anterior surface of the scape and anterior surface of T 1 in O. conjuncta (shiny in O. marilaunidii ), the relatively densely punctate metepisternum (sparsely punctate in O. marilaunidii ) and the lack or reduction of impunctate lateral areas subapically on S4 (large lateral impunctate areas occur in O. marilaunidii ).

Distribution. Eastern United States and adjacent Canada as far west as Kansas ( Fig. 15 ).

Material Examined. Canada. Ontario: Bancroft , 18 May 1961 G Knerer; Cambridge, 12km E, Beverly Swamp, 20 Jun 2001 ; Cookesville , 3 Jun 1960 ; Eagle , 22 May 1965 ; Edsall , 20 May 1917 ; Forks of Credit , 26 Jun 1969, P. MacKay ; Hilton Falls , 15 Apr 2000, T Romankova; London, 7 May 1981, DG Krementz; Maple, 26 Apr 1962, G Knerer; Palgrave, 8 Jun 2002, T Romankova; Palgrave, Duffy’s Line, 18 Mar 2006 ; Point Pelee, 10 May 1961, G Knerer; Terra Cotta , 27 May 2000, T Romankova; Toronto, 24 Apr 1946, CEA Atwood . Quebec: Rouville Co , 25 May 1906, [no collector]. USA . Connecticut: Fairfield Co, Stamford, 14 Apr 1930 . District of Columbia : Washington, 1935, JC Bridwell . Florida: Miami-Dade Co, Key Biscayne, 15 Feb 1925, S Grenicher; Sanford Co, Seminole, 12 Mar 1927, FM Uhler . Georgia: Clarke Co, Athens, Whitehall Preserve, 9 Apr 1979, RH Turnbow Jr . Kentucky: Barren Co, Cave City, 22 Jun 1996, L Strange . Maryland: Anne Arundel Co, Laurel, Patuxent Wildlife Refuge , 8 May 2001 Russell, Droege; Anne Arundel Co, Laurel, Patuxent Wildlife Refuge, 10 May 2001 Russell, Droege; Anne Arundel Co, Laurel, Patuxent Wildlife Refuge, 5 Jun 2001 Russell, Droege; Montgomery Co, Cabin John, 18 May 1915, JC Crawford; Montgomery Co, Chevy Chase, 19 Apr 1919, HL Viereck; Montgomery Co, Chevy Chase, 10 May 1919 ; Montgomery Co, Chevy Chase, 15 May 1919. Michigan: Presque Isle Co, Ocqueoc Lake , 20 Jun 1978, RW Hodges. Mississippi: Oktibbeha Co, 4 May 1991, RL Brown; Oktibbeha Co, Osborn, 1 Apr 2000, B Smith; Oktibbeha Co, Osborn, 19 Apr 2000, B Smith; Oktibbeha Co, Osborn, 29 Apr 2000, B Smith; Oktibbeha Co, Sessums, 8 Apr 2000, B Smith, JA MacGown; Oktibbeha Co, Sessums, 19 Mar 2000, B Smith, JA MacGown. New York: Seneca Co, Cayuga Lake , 8 May 1935, HK Townes ; Seneca Co, Waterloo, 6 mi NW, 18 May 1986, B Alexander; Tompkins Co, Ithaca, 27 Apr 1936 , HK Townes ; Tompkins Co, Ithaca, 6 May 1936 , HK Townes ; Tompkins Co, Ithaca, 2 May 1936, EJ Berberg; Tompkins Co, Van Natta’s Dam, Ithaca, 1 May 1936 . Oklahoma: Latimer Co , [no location], Apr 1989, K Stephan . Pennsylvania: Northampton Co, Wind Gap , 9 Jul 1954, JW Green; Westmoreland Co, Powdermill Nature Reserve, near Rector, 24 Apr 1965, CJ McCoy; Westmoreland Co, Powdermill Nature Reserve, near Rector, 6 May 1965, CJ McCoy . Tennessee: Anderson Co, Oak Ridge, 19 Apr 1965, DJ Burdick; Anderson Co, Oak Ridge, AEC area, 5 Jun 1964 . Texas: Brazoria Co , West Columbia, 5 Mar 1936 ; Matagorda Co, Bay City, 6 May 1953, LD Beamer; Milam Co, Cameron, 9 Apr 1953, LD Beamer. Virginia: Fairfax Co, Great Falls , 19 May 1915, LO Jackson. Wisconsin: Milwaukee Co, Milwaukee, 20 May 1903, S Graenicher.

Floral Associations. Asteraceae : Senecio anonymus , Taraxacum ; Brassicaceae : Brassica ; Fabaceae : Lupinus perennis , Trifolium repens ; Rosaceae : Fragaria , Rosa , Rubus flagellaris ; Rubiaceae : Hedyotis nigricans ; Salicaceae : Salix .

Comments. Osmia conjuncta has been documented as nesting in snail shells ( Rau 1937) and is likely polyletic ( Hurd 1979).

Figures

FIGURE 2. Female faces: A) O. marilaunidii (DRO 4915), B) O. aliciae (BBSL 204540), C) O. gonzalezi (BBSL 204546), D) O. conjuncta (BBSL 695035). Scale bar = 0.5 mm.

FIGURE 7. Male S 3 – S 5: A) O. marilaunidii (BBSLID 95518), B) O. conjuncta (BBSLID 95507). Scale bar = 0.25 mm.

FIGURE 8. Male T 6, T 7: A) O. subfasciata (BBSL 96965), B) O. aliciae (BBSL 204527), C) O. conjuncta (BBSL 839526). Scale bar = 0.25 mm.

FIGURE 15. Known distribution of O. conjuncta (red triangles) with expected distribution based on maxent modeling (rose coloring). Scale bar = 200 km.