Potential effects of cold-snaps and heat-waves on spotted lanternfly nymphs

Spotted lanternfly (SLF) is an invasive species that is native to Asia. The thresholds for nymphal development have already been estimated using constant temperatures but preliminary work suggested that SLF should be able to handle short heat waves that are higher than what it can successfully develop at when under constant temperatures. To continue to refining the stage-specific temperature response data to be used in developing a phenology model, nymphs were exposed to heat (35° or 40°C) or cold (5°C) for a portion of the day (remainder of the day 20°C) and their development and survival was compared to nymphs held at the equivalent average constant temperature (15 or 25°C). Newly molted first and seconds were used in the cold-wave part of the study, and newly molted third and fourth instars were used in the heat-wave part. Preliminary results indicate that both cold-snaps and heat-waves increase developmental time and reduce survival when compared to the corresponding average constant temperatures. Nymphs were, however, able to survive and molt when exposed for only portions of the day to these extreme temperatures which were lethal when nymphs were exposed to them for the full 24 hours. Based on this information the potential range of climates the lanternfly can establish in may be broader than first thought.