Impervious surface: Increased tree canopy temperature and evergreen bagworm overwintering survival

The evergreen bagworm (Thyridopteryx ephemeraeformis Haworth) (Lepidoptera: Psychidae) enter diapause to survive the extreme cold weather. We predicted that impervious surface could keep canopy temperatures warm enough to improve bagworm survival. A total of 1303 and 952 bagworms were collected in 2018 and 2019 respectively with latitude ranging from 39.93 to 41.47. The maximum temperature during the coldest day (January 1, 2018 and February 2, 2019) was used to predict the survival of eggs. Impervious surface within a 20 m radius of each host tree was estimated by pace to plant technique. The canopy temperature was measured using installed temperature probe on tree starting 20^th December 2019 to 20^th March 2020. Length of pupae was measured and two pupae with/or near average weight were sampled from each site to calculate percentage live eggs from first 50 eggs. Remaining bags were kept in room temperature in lab and monitored daily until larvae hatched for 12 weeks. Both years, the survival of egg masses depend on amount of impervious surface around the host trees. Increased impervious surface area around the tree increased the tree canopy temperature. Therefore, impervious surface around host trees can create a temperature buffer zone where marginally hardy species like bagworm can easily survive.