Sugarcane Breeding Institute, Coimbatore-641 007, Tamil Nadu (India).
Biology of the sugarcane mealybug, Dysmicoccus carens Williams was studied on different sugarcane genotypes, viz, Co 740, Co 7704, C 6806, CoC 671, and Co 6907, under laboratory conditions. The pkst was observed to be viviparous with four nymphal instars preceding the adult stage. The life cycle ranged from 48.2 to 63.8 days as a result of rearing on CoC 671 and Co 740, respectively. The mean fecundity was lowest (117.6 crawlers/adult female) when the insect was reared on Co 6907 and highest (230.6 crawlers/adult female) due to rearing on Co 740. The longevity of male was only 3–4 days. The females reared on Co 740 lived for longer duration i.e., 32.3 days and the lowest (18.0 days) on CoC 671. The mean duration of the first instar as observed on different genotypes varied from 4.8 days in CoC 671 to 6.1 days in Co 6806. The duration of second instar was least i.e. 4.1 days due to rearing on CoC 671 and maximum (5.8 days) on Co 7704. The span of third instar reared on CoC 671 was least (5.1 days), whereas on Co 6806 it was maximum (6.1 days). The duration of fourth instar ranged from 13.5 days in Co 6907 to 15 days in Co 7704.
