I currently shoot solely with the AF-S Nikkor 18-200 mm. zoom lens. This is inadequate for closeups of flowers, bugs, and so on. I'm wondering if Nikon has a nice closeup zoom lens that will give me sharp results (I like the flexibility of zoom lenses). Failing that, can someone recommend the best Nikon closeup lens for such purposes. I'd like to keep it under $1,000.
There are zooms that have a "macro" setting but these are not true macro lenses. There are no macro/micro (Nikon calls them "Micros") zooms currently manufactured by Nikon. There is an older zoom, the 70-180mm, that is a true macro/micro, but it still sells for over $1000 used.
There are a number of good fixed focal length macro lenses made by Nikon and others. Examples are:
Nikon doesn't currently make a macro zoom lens or a zoom lens that will get you much closer than your 18-200mm zoom. Nikon did make a macro zoom, the AF 70-180mm f4.5-f5.6. It focused down to 1:1.3 at 180mm, not quite 1:1. It's a very good lens but was discontinued some some ago. It's now very hard to find and the price keeps rising to where now it costs more than it did when new. The going price is now between $1400 and $1800 used. I paid $999 for mine over 4 years ago and mine, though used, was mint in the original box.
Nikon's current macro lenses which will focus down to 1:1 are extremely good lenses and are priced below your $1000 limit.
For field use and at a good working distance your best lens for the purpose is the AFS 105mm f2.8 VR lens for $899. My choice for a DX macro lens would be the AFS DX 85mm f3.5 VR lens for $479. I would stay with the AFS lenses just in case you get a new body in the future, like the D5100 or D3200, that require AFS lenses for auto focus.
Wonderful replies and information.I like the sound of Leonard's recommendation of the AFS DX 85mm f3.5 VR lens for $479. Thanks, George, for the link to closeup photography. Thanks for taking the time.