Its nothing but Latent Defects. This defects we can't 
observe proper identification. On going we can observe or 
client place we observe. Generly 5% in the applications

SORRY vera Reddy i am not agreeing with your answer

pesticide defect is related to defect immunity.
for example if a farmer used one brand of pesticide first 
time to save the crop  from viruses and insects first time 
it works effectively,then gradually it's efficiency gets 
reduced for each use of pesticide later.

this is because of the anti crop agents like viruses and 
insects develop immunity against the pesticide.

like this if you use same type of test cases and test data
for every application testing after some time the testcases
may not detect a single bug.

because the the development people get contious of their 
past defects and generally they won't commit similar 
defects again.

like this defects also get immunity against test cases.

V.nicely explained, Rajender. Thanks a lot.

Hi Rajendra it was well explaind. i have one more question 
arising, when we say pesticide defect is this a review 
defect or testing defect. Can you put little more light on 
this.

chitra