You are out for a meal and you order a bottle of wine that is fairly expensive and not available by the glass. Around the third time the server pours (you're on the second bottle now), you notice there is a fruit fly in your glass along with a significant amount of this somewhat pricey wine. You're not dining al fresco (which is clearly eat/drink at your own risk when it comes to critters) so this is theoretically unexpected. Although not an incredibly high-end fine dining establishment, it's a crisp linens, average $25 entree sort of place. Should you not be the kind to fish it out yourself, what are your expectations of the server?
Should s/he offer to 'remove' the offending beastie for you? Offer fresh (but empty) stemware? An entirely new bottle of wine? What if the last bottle you had was the last in the house?
Also, do your expectations differ according to the price of the bottle?