RE: Irradiation of Med Fruit Fly

["Neil, David M" <neildm@id.doe.gov>]

I think he's concerned that they won't all be sterile, and that "Murphy"
will arrange for some mutation which is bad from a human perspective.
Notwithstanding the odds against it happening.

Dave Neil
neildm@id.doe.gov

> -----Original Message-----
> From:	Bernard L Cohen [SMTP:blc+@pitt.edu]
> Sent:	Wednesday, August 19, 1998 8:39 AM
> To:	Multiple recipients of list
> Subject:	Re: Irradiation of Med Fruit Fly
> 
> 	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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