Re: Irradiation of Med Fruit Fly

[Bernard L Cohen <blc+@pitt.edu>]

	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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