Comparisons were made of the effects of temperature and duration of low temperature on hatch of newly laid egg masses of the invasive spotted lanternfly, Lycorma delicatula (White), under laboratory conditions. Egg masses were collected in mid-October 2019. There was a positive non-linear relationship between temperature and developmental rate (1/d) for eggs held at constant temperatures. The lower threshold for egg development was estimated as 7.39°C. Eggs held at constant 10, 15, and 20°C were estimated to require 635, 715, and 849 DD7.39, respectively, to develop. Diapause was induced with as little as 7 days of chill at either 5 or 10°C. Our data suggest that temperature is the driving factor for diapause termination in spotted lanternfly but other abiotic factors should be investigated. Identification of temperature thresholds for egg hatch and degree day requirements for winter/spring development to the first instar will improve predictive distribution models as well as the creation of predictive phenological models.
