The Colorado Department of Agriculture has some pest control and pesticide licensing exams that must be taken for certain state licenses. These apply to qualified supervisors and certified operators. The difference between the two licenses is that qualified supervisors generally need experience, the amount of which varies by category. A general exam is required of all applicants. Then, each applicant takes one or more category exams, of which there are more than 20.
One way to help prepare for these tests is to just get a job with a licensed pesticide applicator. These applicator companies are allowed to hire unlicensed technicians. They are also required to train these technicians. So you can get some amount of technical knowledge and hands-on experience through a technician job. In fact, the Department of Agriculture states that some questions on the exams are from common knowledge you would learn on the job, not necessarily from a book.
Likely, not all technicians would be able to fully prepare for Colorado pest control exams exclusively through company training. So it is recommended that you put in at least some self-study if you want to take a test to become a certified operator or qualified supervisor.
The Colorado State University Extension Store website has a number of pesticide guides.
These guides are not free. For example, the application and safety guide for ornamental pest control is $25.
Be aware that both qualified supervisor and certified operator license applicants must also take a general exam in addition to any applicable category exams. The study guide for the general exam is also $25.
I ran through the various books in July of 2016, and I discovered that almost all of the books are priced the same as those mentioned above. A few were $30, and a small number were only $6 or $15.
There are some additional test-prep references listed in the Department of Agriculture’s licensing and exam booklet. Look on Page 10, Section C. This section has traditional text and reference books.
There is a page on the Department of Agriculture’s website with specific instructions on how to register online to take the Colorado pest control tests. As of the time of this post, the fees are about $31 per exam. Although you register online, these are not online tests. You must show up and take exams at a physical location.