In Act I Banquo says, "The instruments of darkness tell us truths/Win us with honest trifles, to betray's/In the deepest consequences." What can you infer about Banquo's feelings about the witches? Banquo doesn't trust himself to make any decisions regarding the witches Banquo doesn't trust the witches because they one tell us the good and not the bad Banquo doesn't believe in the witches prophecies because they are evil Banquo wants to believe the witches have his best interests in mind

Banquo in those words means that many times the "bad guys" do not have to lie, cheat or hurt us physically. In the case of witches they do not lie to them but they tell half truths to Mcbeth and Banquo, this makes Mcbeth tempt to follow the predictions of the witches without thinking that there may be other truths and consequences. In the end, these half predictions lead Macbeth to its ruin.

According with the last, Banquo doesn't trust the witches because they only tell us the good and not the bad. They just give half truths.