Drupal Image Attach only need 2 image sizes for my content type

Question

When I use image attach it's creating too many extra images that I don't need. I created a content type called "content_area_4" with Image Attach allowed. I then created an image size called "content_area_4_thumbnail" with a Scale & Crop of 160 x 130. When I go to create a node type of content_area_4 with Teaser image size: content_area_4_thumbnail Full node image size: Original

When I attach an image, it's creating 7 different sizes. I see that it must be because I have 7 different sizes in the "admin/settings/image" page but I only want 2 sizes for this content type, not all of the other sizes also. Is there a module add-on or hack to make this work for selecting which images I want resized by content type?

thanks