Life cycle changes during 12 successive generations of laboratory colonisation of the leafrollerCnephasia jactatana(Walker) (Lepidoptera: Tortricidae) on artificial diet

Abstract

Close monitoring of the lepidopteran leafroller Cnephasia jactatana under laboratory colonisation revealed few distinct effects of successive rearing on artificial diet on the life cycle. The second laboratory generation had a prolonged development time and altered sex synchronism in pupation and eclosion patterns. Some deleterious changes were observed in later generations, including decreases in fertility, egg hatch and sperm motility, failure of mating adults to separate, and pupal and adult malformations. These changes were not adaptive, but were due to incompatibility with the general purpose diet (GPD) used; they were absent under sub-colonisation on a sheepnut-bean based diet (SBD). Success in the laboratory colonisation of C.jactatana is attributed to a random mating protocol, choice of environmental conditions representing the wild habitat, and a rapid rate of population growth.

Adult activity patterns of <i>Cnephasia jactatana</i> Walker (Lepidoptera Tortricidae)

“…Because C. jactatana is not present in any of the countries that import New Zealand horticultural crops, it is considered a quarantine pest (Steven 1990). Foster et al (1993) identified the female sex pheromone for C. jactatana, and Ochieng '-Odero & Singh (1992) and Jiménez-Pérez & Wang (2001) have provided useful information on the biology of this species. However, there has been no report on its adult activity patterns, making the development of behaviour-based and environmentally friendly control tactics difficult.…”