As soon as Test Engineer finds a Bug will Raise the bug as 
in NEW Status and will post it development Tl and Will keep 
it in Open Status and assign it to concerned developer. and 
he can change the status of bug as duplicate, As designed, 
not Reproducable, if it is a bug then developer will work 
on it and give it as Fix status. Then Tester will retest 
that bug and see that it is reproducable or not if it is 
not reproducable then he will close the bug, if its 
reproduce the same bug then keeps it in reopen status.

In my organization bug life cycle starts with a defect I 
found and will shoot a mail to development lead keeping a 
status as NEW, then development lead is going to assign it 
to the developer as status OPENED (if it is really a bug), 
then developer is going to fix that bug and shoot a mail to 
directly to me(test engineer) saying it is FIXED. I will 
retest(FIX VERIFY) that bug and shoot a mail to the test 
lead if it is FIXED and finally test lead will change a 
status of the bug to CLOSED by shooting a mail.

when we found a defect set the status as New and set the 
severity bug revied by the in our seniour people based on 
the severity they will set the priority and then they will 
assign to the corresponding developer based on the priority 
developer  fix it,and then assign to corresponding tester 
and again r-tested he will fix correctly close the bug,if 
it is reproducible then re-assign to the corresponding 
developer.

as soon as tester receive the build or software the tester 
test the application and execute the test case.if the 
tester found the bug in the testing he l"l termed as "new".
the pm analyse the defect & he l'l give to the developer.
the developer l"l "open" it now the developer is rectifying 
the bug.and after solving he l"l "fixed" he bug.then the 
regression testing is oocured whether the bug is fixed or 
not if fixed then the tester l"l "closed" it.if the bug is 
not rectified then then the tester reports a bug then the 
pm do all the above activitys. tis is the bug life cycle