Synergistic and Antagonistic Interactions Between Varroa destructor Mites and Neonicotinoid Insecticides in Male Apis mellifera Honey Bees

• DOI: 10.3389/fevo.2021.756027
• Publication Date: 2021-11-19T11:11:57Z
• Authors: Selina Bruckner; Lars Straub; Peter Neumann; Geoffrey R. Williams
• Keywords: Neonicotinoid; Varroa sensitive hygiene; Clothianidin; Drone

Pressures from multiple, sometimes interacting, stressors can have negative consequences to important ecosystem-service providing species like the western honey bee ( Apis mellifera ). The introduced parasite Varroa destructor and neonicotinoid class of insecticides each represent important, nearly ubiquitous biotic abiotic bees, respectively. Previous research demonstrated that they synergistically interact negatively affect non-reproductive female workers, but no data exist on how concurrent exposure may reproductive males (drones). This is given health females (queens), possibly because poor mating, frequently cited as a major driver colony loss. To address this, known age cohorts drones were obtained 12 colonies—seven exposed field-relevant concentrations two neonicotinoids (4.5 ppb thiamethoxam 1.5 clothianidin) during development via supplementary pollen patties; five colonies received patties not spiked with neonicotinoids. Artificially emerged assessed for natural V. infestation, weighed, then allocated following treatment groups: 1. Control, 2. only, 3. Neonicotinoid 4. Combined (both mites neonicotinoid). Adult maintained in laboratory cages alongside attendant workers (1 drone: 2 worker ratio) until reached sexual maturity after 14 days so sperm concentration viability could be assessed. suggest interacted adult drone survival, antagonistically emergence mass. Although sample sizes too low assess effects combined quality, we observed influence or viability. Our findings highlight diverse severely number sexually mature available mating.