Healthy native pollinator communities contribute to productivity and biodiversity in both natural and agricultural ecosystems

The Board of Trustees of Illinois State University received a $150,000 Project Grant award from the U.S. Fish and Wildlife Service under the Endangered Species Recovery Implementation program (CFDA 15.657) for a three-year research initiative extending from May 20, 2025, through May 19, 2028. This grant supports critical research on bumble bee population decline, with particular focus on the federally endangered Rusty Patched Bumble Bee and related species within the Bombus sensu stricto subgenus. The project will deliver two primary research products: (1) comparative laboratory-based experimental studies assessing susceptibility of representative bumble bee species to proposed drivers of decline, including pathogens, poor nutrition, and agrichemicals, with analysis of synergistic effects and underlying molecular mechanisms; and (2) development and validation of nondestructive sampling methodologies using feces to assess bumble bee community health indicators, including pathogen presence and loads, individual bee diet, and genetic variation.

The research will generate evidence-based knowledge essential for informing bumble bee population management and reintroduction strategies. By establishing standardized protocols for detecting population health metrics and identifying differential susceptibility factors across species, the project will provide actionable information to support federal and state conservation efforts aimed at preventing extinction and facilitating recovery of threatened bumble bee species. Work will be performed at Illinois State University's Normal, Illinois location.

Yet many insect pollinator species have experienced significant reductions in population sizes and range in recent decades. In north america bumble BEE declines appear to have a signal of relatedness with many threatened species in the same subgenus which includes the federally endangered rusty patched bumble BEE. This suggests that this group has a susceptibility to factors detrimental to bumble BEE population health. Bumble BEE population health and future reintroductions and management of threats all rely on knowledge of existing stressors and ecology and measures of population health such as genetic variation. The continuing work has two objectives. 1. A comparative analysis of susceptibility of a representative of this species to proposed drivers of decline and 2. An assessment of nondestructive sampling from feces to assess bumble BEE community health. For the first objective using lab colonies of surrogate species within bombus sensu stricto and comparison nonthreatened species within native bumble BEE communities from other subgenera a series of experimental exposure studies following established protocols will be carried out to assess susceptibility to pathogens and poor nutrition and agrichemicals linked with declines. In addition combinations of these stressors will be assessed for synergistic detrimental effects. Where phenotypic differences in susceptibility are uncovered a targeted molecular approach will be taken to uncover underlying mechanisms. The second objective will build on preliminary data on the nondestructive sampling of feces to assess pathogen presence and loads. This will be expanded to assess if feces can be used to accurately detect other common and decline associated pathogen and an individual BEE diet and genetics. Verification of approaches and information gained on potential differential susceptibility and its root cause will inform stressor assessments and remediation efforts that are critical for not only the health of existing bumble BEE populations but also feasibility of potential future reintroductions.