Osmia (Osmia) lignaria lignaria Say, 1837

Zarrillo, Tracy A., Stoner, Kimberly A. & Ascher, John S., 2025, Biodiversity of Bees (Hymenoptera: Apoidea: Anthophila) in Connecticut (USA), Zootaxa 5586 (1), pp. 1-138 : 133

Osmia (Osmia) lignaria lignaria Say, 1837

Eastern Blue Orchard Mason

Notes: Osmia lignaria lignaria has not been collected in Connecticut since 2017, despite considerable collecting efforts for megachilids in recent years, including in agricultural settings (C. T. Maier unpublished). Interesting to note that in 1905, Osmia lignaria was the most abundant bee collected in apple, at 19% of all bees (Britton and Viereck 1906), while recently in NY apple orchards, O. lignaria represented 0.04% of the bees in apple, and all species of Osmia together represented 0.2% (Russo et al. 2017). LeCroy e t al. (2020) in the mid-Atlantic states reported O. lignaria to be declining 2003–2017 at a mean rate of 13.78% per year.