The Library Catalog uses Library of Congress subject headings that can also help you identify illustrated books on a desired subject.
One subject heading construction is in the form of "X in art" -- for example,
• “birds in art”
• “food in art”
• “saints in art”
• “gardens in art”
Try seeing if your topic might exist in this subject form. Put your search in quotation marks to search as a phrase.
Another subject heading construction incorporates an ending of "pictorial works." For example,
• Birds--pictorial works
Enter [your term] AND "pictorial works” in the Advanced Search as keywords, or try the same search in Subject keyword fields.