REPRODUCTIVE CHARACTERISTICS OF MODAL ECORACE OF REPRODUCTIVE CHARACTERISTICS OF MODAL ECORACE OF WILD TASAR SILKMOTH, ANTHERAEA PAPHIA LINN. IN DIFFERENT ALTITUDES OF SIMILIPAL BIOSPHERE RESERVE, ORISSA, INDIA

Abstract

The life cycle of Modal ecorace of wild tasar silkmoth, Antheraea paphia Linn. is trivoltine (TV), bivoltine (BV)
and univoltine (UV) in lower, middle and higher altitude respectively in Similipal Biosphere Reserve. The life
span in each stage (egg, larva, pupa, moth and diapause period) of life history of Modal ecorace increases
irrespective of rearing season from lower altitude to higher altitude (i.e., from TV to UV form). The factors of
reproductive efficiency (multiplication efficiency) such as percentage of pupal survivability, coupling, fecundity
and hatching of eggs of this ecorace increase with an increase in altitude and from TV to UV form whereas the
reverse trend is observed in the pupal mortality and juvenile mortality. The productive efficiency and commercial
traits such as effective rate of rearing, cocoon weight, pupal weight, shell weight, shell ratio and total shell
production of Modal ecorace are noticeably increased with increase in altitude in each crop season and from TV
to UV type. The wide geographical condition with varying climatological parameters of Similipal Biosphere
Reserve regulates the voltinism, the reproductive biology and economic traits and finally influences the population
structure of the Modal ecorace of Antheraea paphia.