Re: Irradiation of Med Fruit Fly

["Mike Malaxos" <rss@arach.net.au>]

1.	I would worry about the mutations because of the possibility of breeding
a mutated offspring instead of total sterilisation. Are you saying that
this is not a point of concern because no mutations capable of breeding
would be produced or that the most mutant offspring would die before living
long enough to reproduce.

2. & 3 	Can you comment on the last three questions which relate to methods
which allow the use of lower doses to produce the same sterilisation yield
allowing a shorter exposure time and an increased through-put rates.

Thanks for your Help 



 

Best Regards
M.Malaxos
Radiation Safety Services
69-71 Robinson Avenue Belmont
Western Australia.  6104 
Fax 61 89 475 0165
P 61 89 475 0099  a/h 089 255 1214
email rss@arach.net.au
 

----------
> From: Bernard L Cohen <blc+@pitt.edu>
> To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Subject: Re: Irradiation of Med Fruit Fly
> Date: Wednesday, 19 August 1998 22:38
> 
> 	Why should you worry about mutations or any of the other issues
> considered? The purpose of the project is to make a large number of males
> sterile because females mate ony once and if the mating is with a sterile
> male, no new medflies are produced. If essentially all males in an
> area are sterile, the medfly population is eliminated. That is all that
> matters. It doesn't matter whether there are other effects on those
> irradiated, as they will all be dead very soon, and they will have no
> progeny. 
> 
> Of course, if you look at things from the viewpoint of the medflies, the
> perspective is very different. But from the perspective of any pest
> insects, humans are fantastically terrible murderers.
> 
>  Bernard L. Cohen
> Physics Dept.
> University of Pittsburgh
> Pittsburgh, PA 15260
> Tel: (412)624-9245
> Fax: (412)624-9163
> e-mail: blc+@pitt.edu
> 
> 
> On Tue, 18 Aug 1998, Mike Malaxos wrote:
> 
> > Hullo all,
> > 	My query relates to a fruit fly eradication program by sterilisation
of
> > the pupae.
> > 
> > Can any of the group provide information concerning the relationship
> > between age of pupae when irradiated, dose received, level of
sterilisation
> > versus rate of mutation for different dose rates.
> > 
> > Details of the pupae being irradiated are as follows.
> > 
> > Ceratitis Capitata  Med Fruit Fly.
> > Cycle is Eggs 2-4-days, grubs(maggots)  14-16 days Pupae 12 days
irradiated
> > on the 10th day.
> > 
> > The original dose used for sterilisation was 10 - 20 kRads over a
period of
> > about 15 seconds
> > at a dose rate of around 40 kRads/minute.
> > 
> > Because of source decay the dose rate has dropped to around 2.5
> > kRads/minute and the exposure time increased to 4-8 minutes. Between 10
and
> > 20 kRads are required to induce sterilisation. 
> > 
> > It is feared that the mutation rate may have increased significantly
> > because of the lower dose rate.
> > Can anyone provide the following answers.
> > 
> > Will the mutation rate increase significantly because of the lower dose
> > rate?
> > If so, can the rate of mutation be decreased by irradiating the pupa at
a
> > different stage of the life cycle?
> > 
> > Can the dose required to produce sterilisation be reduced by
irradiating
> > the pupa at a different stage of the life cycle.?
> >   
> > Can the pupa be pre-treated by preheating (warming with microwaves) to
> > increase the radio-sensitivity?.  
> > 
> > Please direct any answers not of general interest to me.
> > Thanks in advance for your help.
> > 
> > Best Regards
> > M.Malaxos
> > Radiation Safety Services
> > 69-71 Robinson Avenue Belmont
> > Western Australia.  6104 
> > Fax 61 89 475 0165
> > P 61 89 475 0099  a/h 089 255 1214
> > email rss@arach.net.au
> >  
> >
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