Honey Bee Viromes from Beekeeping Operations Experiencing High Losses in 2022-2023

Area of Science:

• * Virology
• * Entomology
• * Apiculture

Background:

• * Honey bee (Apis mellifera) colonies face significant annual losses, averaging 40% in the US (2008-2025).
• * Viruses are a major pathogen group affecting honey bee health and contributing to colony losses.
• * Next-generation sequencing (NGS) aids in discovering new honey bee viruses and understanding the honey bee virome.

Purpose of the Study:

• * To investigate the honey bee virome in commercially managed colonies experiencing population decline.
• * To identify potential new viruses or genomic variants associated with these declines.

Main Methods:

• * RNA sequencing of honey bee samples from longitudinally monitored, commercially managed colonies in California.
• * Samples were from colonies experiencing an average ~44% population decline during the 2022-2023 season.
• * Re-sequencing of 16 known bee/Varroa mite viruses and 2 poorly characterized partitivirus-like sequences.

Main Results:

• * Discovery of three undescribed, prevalent, and abundant partitivirus-like sequences across all operations.
• * Identification of a new Lake Sinai virus and a sequence variant of acute bee paralysis virus.
• * Higher virus abundance was observed in samples from colonies that perished during monitoring.

Conclusions:

• * The study identified novel viruses and variants within declining honey bee populations.
• * Findings suggest a potential association between specific viral profiles and colony mortality.
• * Further research is needed to understand the role of these newly identified viruses in honey bee health.