A comparitative study to evaluate the efficiency of Coleus forskohliiroot extract and Forskolin as a repellent against Uzi fly (Exorista bombycis)

Abstract

Author(s): Shilaja Yougender Nayini*, Chandra ShakarReddy Nalagoni, Rajkiran Reddy Banala, Sabita S.Raju

Coleus  forskohlii  (CF) is  a  well-known  medicinally  important  plant  and  it  has  been  part  of Ayurveda  for  decades.  Forskolin,  a  diterpene  and  active  constituent  of Coleus  forskohliiroot  extract  (CFRE). The  CFRE has been used for  treating various infections and chronic diseases.  But the  CFRE has  never been used as a pesticide. Exorista bombycis(Uzi fly) is a common pest found to infest Bombyx mori(Silk worm) and cause severe loss to sericulture farmers or  community. Uzi fly targets the  fifth instar  larvae of silk worm to lay  its eggs  and  for  the  propagation  of  its  species.  CFRE  and  Forskolin  were  evaluated  for  its  anti-Uzi  fly properties  and  the  Uzi  fly  maggots,  Uzi  fly  pupae  were  treated  with  different  concentrations  of  CFRE  and Forskolin were used i.e. 0.5, 1.0, 1.5, 2.0 μg/μL. It was observed that the normal growth and development of Uzi fly were hindered at different stages of its life cycle. The fifth instar larvae of silkworm were treated with 0.5-2.0  μL  of  CFRE  and  Forskolin  which  resulted  in  oviposition  deterrence,  reduced egg   hatching, aberrations and deformities in pupae  and adult (i.e.  molting process,  ecdysial failure) and adult emergence from  pupae.  The  observations  from  the  present  study  clearly  suggest  that  CFRE  and  Forskolin  can  be  an alternative for commercially available pesticides for preventing the propagation of Uzi fly by influencing its growth,  development,  and  metamorphosis  of  immature  stages  of  Uzi  fly.  The  efficacy  of  CFRE  is  slightly better than Forskolin in exerting its anti-Uzi fly properties.