Protandrena (Andinopanurgus) guarnensis Gonzalez & Ruz, 2007

Gonzalez, Victor H., Engel, Michael S. & Sepúlveda, Paula A., 2013, Taxonomic and biological notes on Andinopanurgus (Hymenoptera: Andrenidae), Journal of Melittology 2013 (3), pp. 1-10 : 6-7

Protandrena (Andinopanurgus) guarnensis Gonzalez & Ruz

Protandrena guarnensis Gonzalez & Ruz, 2007: 402 [♂].

Rhophitulus guarnensis (Gonzalez & Ruz) ; Ascher & Pickering, 2012 [unjustified combination]. Andinopanurgus guarnensis (Gonzalez & Ruz) ; Moure et al., 2012 [unjustified combination].

NEW RECORDS: Colombia: 6♀♀, Antioquia, La Unión, Corregimiento Mesopotamia, Vereda el 40.0.5°54’27.4’’N 75°18’42.3’’W, 2575m, 20°C, 63% HR, 20, 21, 24 Jul 2009 , Sepúlveda-Cano, P.; Osorio, N.; 23♀♀, idem except: El Carmen de Viboral, Vereda la Palma, 06°06’56.3’’N, 75°20’12.8’’W, 2110 m, 24°C, 65% HR, 25 Aug, 17, 18, 20, 21 Nov 2009 ; 6♀♀, idem except: Envigado, Vereda La Loma del Escobero , 06°08’04.6’’N, 075°32’17’’W, 2459 m, 19.4°C, 65% HR, 19, 20, 21 Nov 2010 ( MEFLG, SEMC, BBSL, AMNH).

COMMENTS: This Colombian species was only known from the municipality of Guarne, Antioquia; the female sex was previously known from a single paratype in poor condition.

FORAGING BEHAVIOR ON POTATO FLOWERS: Protandrena guarnensis was the only andrenid visiting flowers of S. tuberosum among 70 species of bees belonging to the other four families present in Colombia (Sepúlveda & Smith-Pardo, unpubl. data). Females of P. guarnensis visited a single flower per plant. About 86% of the observed visits (n = 35) of P. guarnensis on potato flowers were recorded between 11:00 and 13:00 hours, several hours after the anthesis occurred (6:00–7:00 h); remaining visits were recorded between 9:00 and 10:00 hours. To release pollen, females curled into a partial C-shape at the tip of the anthers and sonicated one to four anthers for durations of 9 to 180 seconds (= 78.2, ± 1.47, n = 7); only in half of the observed visits did females contact the stigma. To groom and pack pollen in their metatibial scopae, females gripped the apex of the anthers or style with their hind legs, and either maintained their bodies somewhat perpendicular to or leaned to the anthers, facing the corolla, while removing the pollen with their remaining four legs.

A palynological analysis of the pollen taken from the metatibial scopae of 15 specimens collected at flowers of potatoes showed that on average 80.3% (± 0.36, n = 60 plates) of the pollen grains belonged to this plant; remaining grains belonged to undetermined species of the families Asteraceae , Melastomataceae , and Malvaceae (N. Osorio, pers. comm.).