Abstract
Huckleberry (Vaccinium spp.) is one of the most iconic plants in the Pacific Northwest, prized for the flavor and abundance of its fruit. Despite this desirability, there is no domestic cultivar for any common huckleberry species. Therefore, the need exists for research that examines the basic biology and ecology of multiple species of huckleberry. Plant-pollinator interactions are a key part of many ecosystems, and the specificity of these interactions can provide insight into the importance of different organisms within these ecosystems. To investigate the plant-pollinator interactions for huckleberry in northern Idaho, eight sites were selected in two different forested regions, Priest River Experimental Forest and Idaho Panhandle National Forest. Site locations were selected for high huckleberry density and were established across an elevational gradient. Pollinators were collected while interesting with huckleberry flowers via direct netting techniques and the overall insect communities were sampled via a combination of pitfall and cross-vane traps (blue and yellow). All insects captured on huckleberry flowers were identified to the lowest taxonomic level possible while non-hymenopteran trap-collected insects were identified to the level of genus. Insect communities were compared between those captured on huckleberry flowers versus in cross-vane traps and the diversity of insect pollinators captured in cross-vane traps was compared across sites and between trap permutations (color and height). Comparisons of the insect communities were made using five diversity metrics: richness, evenness, abundance, Shannon’s diversity index, and Simpson’s diversity index. Pollinators captured on huckleberry flowers were similar to those reported in studies that examined other Vaccinium pollinator communities which were primarily bumblebees. Most of the pollinators captured were bumblebee queens. However, some large syrphids were also captured on flowers which may represent a novel group of huckleberry pollinators. Comparisons of diversity across the elevation gradient indicated no differences between any of the diversity metrics used or overall community values. However, trap color significantly influenced community measurements and depended on which diversity metrics were compared. Blue traps captured larger quantities of insects (abundance) while yellow traps captured more diverse communities of insects. For example, Shannon diversity values in yellow traps were higher (1.97) compared with blue traps (0.53), in contrast, Simpson’s dominance values were higher in blue traps (0.792) compared with yellow traps (0.199). These results suggest that while traditional Vaccinium pollinators are present on huckleberry plants in northern Idaho, other less studied pollinators may provide pollination services to the native plants.