Response of Monarch Butterfly (Danaus plexippus) Eggs and Larval Stages to Low Temperature

The purpose of this research was to evaluate the effects low temperature exposure duration (zero, one, three, and seven days) on the development of eggs and larval (first, third, and fifth instars) stages of monarch butterflies (Danaus plexippus). Overall, low temperature exposure resulted in living a fewer number of days and a fewer number reaching the adult stage across all treatments. Low temperature exposure at the egg stage was generally most detrimental, followed by exposure at the fifth instar stage. First instars exposed for one day and third instars exposed for three days had the greatest survival to adulthood of the stages tested. Sudden weather events and changes in climate affect monarch populations; this study, and future related studies, may be a preliminary step towards accurate population predictions and may aid in possible conservation actions.