Abstract:
The fruit piercing moth, Anomis leona Schaus (Lepidoptera: Noctuidae) is a major defoliator pest of cocoa in Nigeria causing severe losses to farmers in the event of outbreak of the pest. There is scanty information on the pest’s biology in Nigeria prompted this study because of its economic importance in the cocoa economy.Larvae were reared from eggs laid in the laboratory, and some life cycle parameters of Anomis leona were investigated in the laboratory at the Cocoa Research Institute of Nigeria (CRIN), Ibadan at an ambient temperature of 27±3°C and 70-80% relative humidity In captivity, the relationship of length of life to adult diet was investigated to provide information on which to base a laboratory rearing technique for this pest of cocoa. The adult insect was fed on 10% commercial sugar solution, a formulation required for it’s gonads maturation.
Measurements of body length and width of different larval stages were taken using a vernier calipers. The detailed morphology of different larval stages of the insect was examined under a binoculars microscope on every moult of the larvae. There were four larval instars and the fourth instar exhibited marked colour polymorphism. Four of such polymorphs were included. The developmental period from egg (2.6days);first instar (7.1days); second instar (2.2days);third instar (2.5days); forth instar (3.3days); pre-pupal (1.0day) and pupal (7.6days) to adult emergence totalled 26.3 days.There was a significant difference in the adult longevity between virgin males and females reared in the wooden and wicker-framed muslin cages. The total life span of virgin females in the wooden cage varied from 5-9 days with a mean value of 6.8 days while that of males ranged from 4-7 days with a mean value of 5.2 days. The total life span of virgin females reared in the Wicker-framed muslin cloth cage varied from 12-15 days with a mean value of 13.3days while that of males ranged from 15-17days with a mean value of 6.2days. There was no significant difference in the adult longevity of mated males and unmated females: Mated males (10.2 ± 1.07days); mated females (12.6 ± 1.64days); unmated males (16.2± 0.77days); unmated females (13.3 ± 1.21days).The sex ratio of male to female was 1:1.36.
