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Ptilothrix bombiformis (Cresson, 1878)


Scientific Name: Ptilothrix bombiformis (Cresson, 1878)

Common Name: Hibiscus Turret Bee


Melissodes bombiformis Cresson, 1878 : 219 [♀, ♂].

     Lectotype ♀, desginated by Cresson (1916: 113). USA, Kansas [ANSP no. 2282].

Emphor fuscojubatus Cockerell, 1913: 107 [♀]. Synonymy by Robertson (1925: 280); Mitchell (1962: 240).

     Syntypes ♀. USA, New Jersey, Cape May Pt., 25 August 1912, by L. Nichols [CAS no. 15480].


Taxonomic notes: This species has been placed in several genera since its description as a Melissodes by Cresson (1878): Patton (1879: 476) designated it as the type species of Emphor Patton, 1879, which was followed by many subsequent authors (e.g., Grossbeck 1911; Lutz and Cockerell 1920); Dalla Torre (1896: 227) placed it in Eucera Scopoli, 1770, though he recognized many eucerine and non-eucerine taxa as subgenera, including Ancyloscelis Latreille, 1829 and Emphor Patton, 1879, though surprising not Ptilothrix Smith, 1853); Friese (1910: 706) placed it in Ancyloscelis. Moure (1947: 240) placed Emphor into synonymy under Ptilothrix Smith.

Robertson (1900: 54) suggested that the female of M. nigripes Smith was not associated correctly with its male (the holotype, from Mount Pleasant, Ohio B.M. Type Hym. No. 1713.836) and listed the former as a synonymy of M. bombiformis Cresson (see also Lutz and Cockerell 1920).

Cockerell (1913) described E. fuscojubatus from three females from New Jersey, noting slight differences in pubescence and integument colour, and wing venation, and indicated that this was the same species mentioned by Smith (1910: 694). Robertson (1925: 280) attributed this to variation within this species and is credited with the synonymy, though Michener (1951: 1218) later treated it as a subspecies. Hurd (1979: 2119) credits Mitchell (1962: 240) with the synonymy.

The North American species were treated by Flórez-Gómez and Danforth (2023). 

Biology: Smith (1910), Grossbeck (1911), Nichols (1913), Robertson (1925), Rau (1930), and Brown (1935) summarized the nesting habits and other aspects of its life history; Grossbeck (1911) described the larval and pupal stages. Ptilothrix are solitary bees that will nest in aggregations in hardpacked sandy soil which they soften with water they collect (Linsley et al. 1956b; Martins et al. 1996; Michener 2007; Flórez-Gómez and Danforth 2023).

Distribution in Canada: Sharkey et al. 2020 [ON]; Flórez-Gómez and Danforth 2023 [ON].

This species has only recently been confirmed from Canada (Sharkey et al. 2020).


Michener CD (2007) The Bees of the World. 2nd Edition. Johns Hopkins University Press, Baltimore. xvi + 953 pp.

Dalla Torre CG (1896) Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Volume X: Apidae (Anthophila). Engelmann, Leipzig, 644 pp.

Hurd PD (1979) Superfamily Apoidea. In: Krombein KV, Hurd Jr PD, Smith DR, Burks BD (Eds) Catalog of Hymenoptera in America North of Mexico. Smithsonian Institution Press, Washington, 2735 pp.

Mitchell TB (1962) Bees of the Eastern United States. Volume 2. North Carolina Agricultural Experimental Station Technical Bulletin 152, Raleigh, 557 pp.

Robertson C (1900) Some Illinois bees. Transactions of the Academy of Science of St. Louis 10: 47-55.

Lutz FE, Cockerell TDA (1920) Notes on the distribution and bibliography of North American bees of the families, Apidae, Meliponidae, Bombidae, Euglossidae, and Anthophoridae. Bulletin of the American Museum of Natural History 42(15): 491-641.

Cresson ET (1878) Descriptions of new species of North American bees. Proceedings of the Academy of Natural Sciences of Philadelphia 30: 181-221.

Cockerell TDA (1913) A new bee of the genus Emphor. Psyche 20(3): 107.

Robertson C (1925) Habits of the Hibiscus Bee, Emphor bombiformis. Psyche 32(6): 278-282.

Rau P (1930) The nesting habits of Emphor bombiformis Cresson. Psyche 25(1): 28-34.

Brown RW (1935) Further notes on fossil larval chambers of mining bees. Journal of the Washington Academy of Sciences 25: 526-528

Friese H (1910) Neue Bienenarten aus Süd-Amerika. Deutsche Entomologische Zeitschrift 1910(6): 693-711.

Grossbeck JA (1911) A contribution toward the life history of Emphor bombiformis Cress. Journal of the New York Entomological Society 19(4): 238-244.

Smith JB (1910) Report of New Jersey State Museum for 1909. MacCrellish and Quigley, Trenton, 888 pp.

Sharkey JK, Pindar A, Raine NE (2020) First Canadian record of the specialist hibiscus bee, Ptilothrix bombiformis (Cresson) (Hymenoptera: Apidae). The Journal of the Entomological Society of Ontario 151: 41-48.

Flórez-Gómez N, Danforth B (2023) The North American bees of the genus Ptilothrix Cresson, 1878 (Hymenoptera, Apidae, Emphorini), with the description of two new species. Journal of Hymenoptera Research 95: 275-293.

Patton WH (1879) Generic arrangement of the bees allied to Melissodes and Anthophora. Bulletin of the United States Geological and Geographic Survey 5(3): 471-479.

Nichols ML (1913) Some observations on the nesting habits of the mining bee, Emphor fuscojubatus. Psyche 20(3): 107-112.

Moure JS (1947) Notas sobre algunas abejas de la provincia de Salta (Hymen. Apoidea). Revista de la Sociedad Entomológica Argentina 13(1-5): 218-253.

Michener CD (1951) Tribe Emphorini. In: Muesebeck CF, Krombein KV, Townes HK (Eds) Hymenoptera of America north of Mexico Synoptic Catalog. 2. United States Department of Agriculture Agricultural Monograph, Washington. Pp. 1218-1221.

Linsley EG, MacSwain JW, Smith RF (1956b) Biological observations on Ptilothrix sumichrasti (Cresson) and some related groups of bees (Hymenoptera, Anthophoridae). Bulletin of the Southern California Academy of Sciences 55: 83-101.

Martins RP, Guimarães FG, Dias CM (1996) Nesting biology of Ptilothrix plumata Smith, with a comparison to other species in the genus (Hymenoptera: Anthophoridae). Journal of the Kansas Entomological Society 69(1): 9-16.

Sociality: Solitary
Nesting: Ground
Pollen Specialization: Narrow Oligolecty
Wintering Stage: Mature Larva

Crop Preference: Not Available
Non Crop Preference: Cirsium sp., Vernonia sp., Hibiscus sp., Cephalanthus sp., Ipomoea sp., Verbena sp.

Distribution: Ontario
Ecozone: Mixwood Plains

Distribution Map