Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Cold Physiology of Pteromalus venustus

Pteromalus venustus is a parasitic species of the agriculturally relevant pollinator Megachile rotundata. The current leading parasite treatment is an aerosol chemical exposure that can present risks to stored bees. As M. rotundata is an introduced species to North America and P. venustus is not, potential gaps in evolutionary gained tolerances may be exploited as treatment options. Chill exposure was explored as a treatment through prolonged exposure to a variety of temperatures, 0° C to -25°C, for varying durations within a week period. Lethal cold limits were similarly investigated. The supercooling point (SCP) of an organism is the temperature at which ice crystals forms within the body and commonly results in death. Using a differential scanning calorimeter (DSC), the organisms were taken to extremely low temperatures at a rate of 1° C per second. When the SCP is reached, the DSC records a spike in heat as the insect freezes. While cold treatment proved unsuccessful as a parasite treatment option, further nondestructive options can be explored through heat or gas mixtures.