Meeting Abstract

36.2  Friday, Jan. 4  Flight metabolic rate as an expression of quality in temperature stressed alfalfa leafcutting bees, Megachile rotundata BENNETT, MM*; OWINGS, A; YOCUM, G; RINEHART, J; GREENLEE, K; North Dakota State University, Fargo; North Dakota State University, Fargo; United States Dept. of Agriculture, Fargo; United States Dept. of Agriculture, Fargo; North Dakota State University, Fargo

The alfalfa leafcutting bee,Megachile rotundata F.(Hymenoptera: Megachilidae)is a solitary species that develops inside a maternally constructed brood cell. Pre-pupal M. rotundata diapause over winter and resume development as ambient temperatures increase. Environmental cues are known to initiate biological processes in many insects, allowing better survival of anticipated stressors, such as temperature fluctuations. However, insects are limited in their ability to deal with extreme temperature fluctuations when not in a diapausing state. To better understand how temperature fluctuations during juvenile development affect adult physiology, we exposed pupal M. rotundata to one of three temperature treatments and assessed changes in adult flight physiology. Pre-pupae were reared normally at 29°C for 14 days. At that point, some insect development was interrupted for 1 week by placement in either constant 6°C or 6°C with a 1h daily pulse of 20°C (FTR). Pupae were returned to 29°C and allowed to develop to adulthood. Because insect flight is metabolically expensive and is essential for success for the next generation, flight metabolism was used to indicate quality. Flight metabolic rates were measured using flow through respirometry. When compared to uninterrupted or FTR development, females from constant 6°C had higher metabolic rates, while males from constant 6°C had lower metabolic rates. Surprisingly, 53% of bees from the 6°C group were unable to fly and had morphological defects. These data suggest that interrupting bee development with placement in a constant 6°C, a common rearing method, negatively affects adult bee physiology.