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Most insects' assemblages differ with forest type and show vertical stratification. We tested for differences in richness, abundance and composition of hymenopteran families and mymarid genera between sugar maple (Acer saccharum) and white pine (Pinus strobus) stands and between canopy and understory in northeastern temperate forests in Canada. We used flight interception traps (modified malaise traps) suspended in the canopy and the understory in a split-split block design, with forest type as the main factor, forest stratum as the first split factor, and collection bottle location as the second split factor. Hymenopteran families and mymarid genera differed in their diversity depending on forest type and stratum. Both family and genera richness were higher in maple than in pine forests, whereas family richness was higher in the canopy and top bottles and generic richness was higher in the understory and bottom bottles. Multivariate analysis separated samples by forest type, vegetation stratum, and bottle location. Family composition showed 77% similarity between forest types and 73% between the canopy and understory. At the lower taxa level, mymarid genera showed only 47% similarity between forest types and 40% between forest strata, indicating vertical stratification and relatively high beta-diversity. Our study suggests that hymenopteran diversity and composition is strongly dependent on forest type and structure, making flying members of this order particularly vulnerable to forest management practices. It also shows that insect assemblage composition (especially at low-taxon levels), rather than relative abundance and richness, is the community attribute most sensitive to forest type and vertical stratification.

BACKGROUND Tranexamic acid (TXA) therapy is effective in reducing postoperative red blood cell (RBC) transfusion in total joint arthroplasty (TJA), yet uncertainty persists regarding comparative efficacy and safety among specific patient subgroups. We assessed the impact of a universal TXA protocol on RBC transfusion, postoperative hemoglobin (Hb), and adverse outcomes to determine whether TXA is safe and effective in TJA, both overall and in clinically relevant subgroups. STUDY DESIGN AND METHODS A retrospective observational study was performed on patients undergoing TJA at our institution spanning 1 year before and after the implementation of a universal protocol to administer intravenous (IV) TXA. The primary outcome was percentage of patients transfused, and secondary outcomes were perioperative Hb and occurrence of adverse events (death, myocardial infarction, stroke, seizure, pulmonary embolism, deep vein thrombosis, and acute kidney injury ). Outcomes were compared in pre‐ and post‐protocol groups with χ2 analysis. Logistic regression compared risk of transfusion in pre‐ and post‐protocol subgroups of patients with differing risk for transfusion (anemia, body mass index [BMI], and sex). RESULTS No differences were found in baseline patient characteristics across pre‐ and post‐protocol groups (n = 1084 and 912, respectively). TXA use increased from 32.3% to 92.2% while transfusion rates decreased from 10.3% to 4.8% (p < 0.001). Postoperative Day 3 Hb increased from 95.8 to 101.4 g/L (p < 0.001). Logistic regression demonstrated reduced transfusion in post‐protocol subgroups regardless of sex, anemia, or BMI (p < 0.001). No increase in adverse events was observed (p = 0.8451). CONCLUSIONS Universal TXA was associated with a reduction of RBC transfusion, overall and in clinically relevant subgroups, strengthening the rationale for universal therapy.

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