Division of Entomology, Central Sericultural Research and Training Institute, Berhampore-742 101, West Bengal (India).
Life cycle of Scymnus nubilus Mulsant, a principal native predator of mealy bug, Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) causing tukra disease of mulberry, Morus alba L. in West Bengal (India) was studied under controlledconditions (25–28°C and 65–70% R.H.) in the laboratory. The duration of egg, grub, prepipal and pupal stages of S. nubilus was 5.5, 10.45, 1.7 and 7.71 days, respectively when reared on M. hirsutus. Biometrical studies provided the measurements of various stages, viz, egg (0.03 x 0.02 mm), grub (1st instar:0.48 x 0.10; IInd instar:0.79 x 0.40; IIIrd instar: 1.76 x 0.78; IVth instar: 3.33 x 1.33 mm), pre-pupa (2.95 x 1.34 mm), pupa (2.24 x 1.63 mm), male (1.25 x 1.10 mm), and female (2.79 x 1.17 mm). Longevity of male and female predator was recorded as 49.9 and 57.23 days, respectively. Copulation period ranged from 6.15 to 7.40 minutes.
