Respiration rates in eggs of the honey bee, Apis mellifera

SUMMARY

Respiration rates in queen-laid and worker-laid eggs of the honey bee, Apis mellifera, were determined for the 3days of embryonic development. Respiration was quantified by measuring the amount of CO₂ produced during 13 h of artificial incubation at four temperature treatments: 28°C, 31°C, 34°C, 36°C (± 0.5°C). The mean respiration rates for fertilized and unfertilized eggs from queens were 140.3 ± 4.0 and 141.2 ± 12.2 nl CO₂/h/egg, respectively. The mean respiration rate for unfertilized eggs from laying workers was 125.1 ± 6.3 nl CO₂/h/egg. Mortality results, as indicated by pre-emergence embryos, showed that 75% developed at 34°C compared to 37.5% at 36°C. Low temperatures of 28°C and 31°C had 12.5% and 50% embryos developing to pre-emergence stage, respectively. Respiration results showed significant differences (P = 0.05) between the different days of incubation and temperature treatments, respectively. No significant difference was observed between the fertilized eggs and unfertilized eggs from queens at the same temperature treatment. The comparison of unfertilized eggs from queens and those from laying workers also showed no significant difference. When CO₂ output on all the days and temperature treatments were compared, a significant regression (R² = 0.645) was obtained (P = 0.05).

Keywords:

• honey bees
• Apis mellifera
• eggs
• respiration
• laying workers
• honey bee queens
• embryology
• development