Biology and feeding efficacy of Micraspis discolor, a potential biological control agent of whitefly, Dialeuropora decempuncta
MV Santha Kumar, UK Bandyopadhyay, N Lalitha and B Saratchandra
Whitefly, Dialeuropora decempuncta Quaintance & Baker manifests chlorosis, dryness, curling of leaves and sooty mould disease in mulberry causing a leaf yield loss of 1630 kg/ha/season. It was reported that a number of whitefly species have developed resistance to chemical insecticides. The hazards of residual toxicity on silkworm are also well known. In view of the above, continuous efforts were made to find its effective natural enemies in mulberry fields of West Bengal. Continuous screening of whitefly infested leaves has lead to the discovery of a native predator, Micraspis discolor Mulsant (Coleoptera : Coccinellidae). To explore possibilities of using this predator as a bio-control agent, its biology and feeding efficacy were studied. The life span of the egg, grub, pre-pupal and pupal stages of this predator was 5, 2.8, 3.27, 3.6, 4.5, 1.27 and 5.6 respectively, when reared on whitefly life stages. Biometrical studies provided the measurement of various stages, viz., egg (0.9x0.55 mm), grub (2.74 x 1.24; 4.2 x 2.02; 4.94 x 3.1, 6.0 x 3.98 mm), pre-pupa (5.36 x 11.7 mm), pupa (4.86 x 13.2 mm), male (8.5 x 6.8 mm) and female (9.6 x 7.63 mm). Longevity of male and female predators was 64.6 and 82.6 days respectively. Copulation period was 4.20 – 18.6 minutes. The fecundity was 42-58. The feeding efficacy studies revealed that fourth instar grub is voracious feeder and female consumed more life stages of D.decempuncta than male.
MV Santha Kumar, UK Bandyopadhyay, N Lalitha, B Saratchandra. Biology and feeding efficacy of Micraspis discolor, a potential biological control agent of whitefly, Dialeuropora decempuncta. J Entomol Zool Stud 2018;6(1):938-941.