Bio-ecology of Coccinellid Beetle, <i>Cryptolaemus montrouzieri</i> Mulsant on Grapevine Mealy Bug, <i>Maconellicoccus hirsutus</i> (Green) under Laboratory Condition

Abstract

The present study was conducted at the Department of Agricultural Entomology, University of Agricultural Sciences, Dharwad, Karnataka, India under laboratory conditions. The mealy bug, Maconellicoccus hirsutus (Green) is major and hard to kill pest of grape vines because of its protected waxy filaments, which are almost impossible to be penetrated with insecticidal sprays. The predatory coccinellid beetle, Cryptolaemus montrouzieri Mulsant has been proved as a voracious feeder and best biological control agent on different mealy bugs. In this study an effort was made to know the developmental period taken by the predator to complete its life cycle on feeding second and third instars mealy bugs. The predatory grub took 3.83 ± 0.53, 4.83 ± 0.65, 6.03 ± 0.85 and 5.67 ± 0.66 days and 3.53 ± 0.51, 4.53 ± 0.51, 5.57 ± 0.50 and 5.50 ± 0.51 days to complete its first, second, third and fourth instar, respectively when supplemented with second and third instar mealy bugs with an average of 3.68 ± 0.36, 4.68 ± 0.33, 5.80 ± 0.57 and 5.58 ± 0.46 days. The results clearly indicated that the duration taken by the predator feeding on second instar mealy bugs was little more than feeding on third instar mealy bugs. The total developmental period of grubs was 20.37 ± 1.29 and 19.13 ± 0.86 with an average of 19.75 ± 0.77 when supplemented with second and third instar mealy bug preys, respectively. The predator grubs recorded pre-pupal duration of 1.73 ± 0.52 and 1.67 ± 0.55, with a mean of 1.70 ± 0.39 days feeding on second and third instar mealy bug. The pupal period recorded was 8.70 ± 0.88 and 8.53 ± 1.22 days, respectively when fed on second and third instar mealy bugs with an average of 8.62 ± 0.82 days. The duration of male beetle when reared on second and third instar mealy bugs was 55.80 ± 3.19 and 60.59 ± 3.73 days, respectively with an average of 58.18 ± 2.13 days. Similarly, the longevity of female beetle was 63.83 ± 1.91 and 61.28 ± 2.21 with a mean of 62.48 ± 1.42 days.