Sex, sperm, and survival of honey bees in changing climates

Monday, November 11, 2024

9:36 AM – 9:48 AM MST

Location: Phoenix Convention Center, 126 A, PCC

Presenting Author(s)

CA

Christopher Allen

University of California
Moreno Valley, California

Co-Author(s)

KP

Kylah Phillips

University of California
Riverside, California
LF

Luis Frausto

University of California
Riverside, California
MJ

Madison Julien

University of California
Riverside, California
Alison McAfee

Postdoctoral fellow
North Carolina State University
Delta, British Columbia, Canada
DZ

Daniela Zarate

University of California
Escondido, California
BB

Boris Baer

Professor Investigador
University of California
Riverside, California

Honey bee queen quality and fecundity is imperative to the production of workers in colonies, and hence, the delivery of pollination services. The queen is not solely responsible for worker production, however, since all fertilized eggs rely on sperm stored in the queen’s spermatheca. During the earliest stages of the sperm’s lifecycle, drones can be exposed to environmental stressors, such as heat, which can reduce male fecundity prior to mating. Here, the goal was to compare the performance of honey bee males exposed to thermal stress from two groups: (1) US Commercial Breeding Lines and; (2) Southern California Wild-Type. We specifically tested males exposed to both 35 C and 42 C to see how this impacted survival and sperm viability. Furthermore, we measured sperm viability both immediately after and four days after thermal exposure. There were no immediate differences in sperm viability between Commercial and Southern California groups after 35 C and 42 C thermal exposure. However, Commercial males experienced a loss in fertility four days post treatment. Southern California males, on the other hand, experienced no loss in fertility long term. We also found that Commercial males exposed to 42 C were at an increased risk of death compared to all other groups. Our results suggest that fewer Commercial males may be surviving after heat waves and may provide less fertile sperm to queens when they do successfully mate. We are currently investigating the molecular mechanisms which seemingly allow Southern California males to robustly handle thermal stress.