PestWeb
http://www.pestweb.com/

National Pest Management Association Formerly National Pest Control Association
http://www.pestworld.org/

UC IPM ONLINE
http://www.ipm.ucdavis.edu/

National Science Foundation - Center for Integrated Pest Management
http://ipmwww.ncsu.edu/cipm/

Pest Control Operators of California
http://www.pcoc.org/