For pictures of apple diseases (including abiotic disorders such as nutrient deficiencies), this site also has some insect photos:
http://www.ipmimages.org/browse/bsubject.cfm?id=74
http://plant-disease.ippc.orst.edu/plant_searchResults.cfm?host_see=Apple
For questions please contact John Aue at
Threshold IPM Services
17336 Merry Hill Rd.
Richland Center, WI 53581
608 538-3192 (home), 608 604-0234 (cell)