Developmental rates of the Lappet Moth Streblote panda Hübner (1820) (Lepidoptera: Lasiocampidae) at constant temperatures

Abstract

Streblote panda Hübner (1820) (Lepidoptera: Lasiocampidae) is a potential pest of forest, floricultural and horticultural plants. This paper reports the rate of development of this species at six constant temperatures between 16.0 and 31.0 deg C (3 deg C increments). Individuals were monitored daily and egg, larval and pupal development times recorded. The development rate was calculated as the reciprocal of the median number of days required to complete development. Linear regression methods were used to estimate lower temperature thresholds and the number of degree-days (DDs) needed for the development of each stage (and total development) under these laboratory conditions. The average hatching time was 18.0 days at 16 deg C and 7.2 days at 31 deg C; the average larval development time was 131.8 days at 16 deg C and 31.7 days at 31 deg C. The egg-to-adult development time ranged from 189.0 days at 16 deg C to 48.5 days at 31 deg C. The threshold temperatures were 7.9, 11.9, 12.5 and 11.3 deg C for egg, larval, pupal and egg-to-adult development respectively. Differences between larval instars were found; threshold temperatures were lower for late instars. The number of degree days (DDs) for egg-to-adult development was estimated at 1000.0 above 11.9 deg C. The results suggest three full generations are possible per year in SW Spain.