4.4 Wood-Destroying Insect Diagnostic Inspections & Category 12

Key Takeaways

  • Ohio defines wood destroying insects as termites, carpenter ants, carpenter bees, and re-infesting wood boring beetles.
  • A wood-destroying insect diagnostic inspection for a real estate transaction requires a commercial applicator license with Core plus Category 12, even if no pesticide is applied.
  • Category 12 applicants must complete the Ohio wood-destroying insect inspection training program, a five-hour class, and submit the certificate with the license application.
  • Findings must be recorded on form NPMA-33 exactly as OAC 901:5-11-13 directs, and where the form's own instructions conflict with the rule, the Ohio rule controls.
  • The employer of any commercial applicator licensed in Category 12 is considered a pesticide business and must hold a business license and carry errors and omissions coverage of $100,000 aggregate and $50,000 per occurrence.
Last updated: August 2026

4.4 Wood-Destroying Insect Diagnostic Inspections & Category 12

Category 12 is unusual: it is a commercial applicator category for work that may involve no pesticide application at all. ODA states it directly - if you perform a WDI diagnostic inspection, you are considered a commercial applicator even if you do not apply pesticides.

What Counts as a Wood-Destroying Insect

OAC 901:5-11-01(R) defines the term for the whole chapter:

"Wood destroying insects" include termites, carpenter ants, carpenter bees, and re-infesting wood boring beetles.

Four groups. Powderpost beetles and old house borers fall in the re-infesting wood boring beetle group; wood-decay fungi are not wood-destroying insects, which is why Category 10A excludes fungi and why a mold or rot finding on an inspection is reported as an observation rather than as a WDI finding.

What Counts as the Inspection

OAC 901:5-11-01(P)(12) defines the category: the examination of a structure at the request of any party involved in a contemplated real estate transaction to determine whether wood destroying insects are present, whether there is evidence they are or have been present, or whether there is visible damage caused by wood-destroying insects - and the generation of a written report of the findings.

The trigger is the real estate transaction. A routine termite inspection for a homeowner with no pending sale is not a Category 12 diagnostic inspection; a pre-closing inspection is.

Getting Licensed in Category 12

ODA's requirements:

  1. Pass the Core exam (90 questions) and the Category 12 exam (65 questions), each at 70 percent.
  2. Attend the OSU Extension WDI Inspection class - ODA describes it as a five-hour Wood Destroying Insect Inspection Training Program. Under OAC 901:5-11-08(A)(4) the applicant submits a valid certificate verifying completion of the Ohio wood-destroying insect inspection program with the license application.
  3. Submit the license application and pay the fee ($35, October 1 - September 30).

The NPMA-33 Form and OAC 901:5-11-13

Ohio does not let inspectors design their own report. OAC 901:5-11-13 requires commercial applicators conducting WDI inspections for real estate transactions to:

  • (A) Conduct all inspections in accordance with the practices set forth in the Ohio wood-destroying insect diagnostic inspection training program, and
  • (B) Make a complete record of the findings of each inspection on form NPMA-33, available through ODA's Plant Health forms page and from the National Pest Management Association.

The rule adds a controlling clause worth memorizing: "In the event of conflicting instructions for completing the form, the provisions of this rule shall apply for all inspections made within this state." Ohio's rule beats the national form's instructions inside Ohio.

Section one of the form

Record completely and accurately:

  1. Name, address, and telephone number of the pesticide business conducting the inspection
  2. The license number of the pesticide business or registered location
  3. The date of the inspection
  4. The physical address of the property inspected
  5. The name, license number, and original signature of the commercial applicator conducting the inspection
  6. The specific structures inspected

Section two of the form - findings

FindingBoxWhat the rule requires you to add
No visible evidence of WDI activityA-
Visible evidence observedBComplete the applicable sub-boxes below
Live insects observedB(1)List the types of insects observed and state the specific location - for example sill plates, foundations
Dead insects, insect parts, frass, shelter tubes, exit holes, staining, or other physical evidenceB(2)Describe the types of insects and parts observed and all other physical indicators, and state the specific location of each
Visible insect damage to the structure3Describe the type of damage and state the specific locations where damage is observed

If the comments exceed the space provided, the applicator attaches supplemental pages and says so on the form.

Records and Retention

WDI inspection records follow the same pipeline as application records. Under OAC 901:5-11-10(B) and (C), the employer and the pesticide business retain records received under 901:5-11-13 for three years from the date of application or inspection, available to the director.

Business and Insurance Consequences

ODA is explicit: the employer of any commercial applicator licensed in pesticide-use Category 12 is considered a Pesticide Business. That employer must:

  • hold a valid pesticide business license ($35, October 1 - September 30), and
  • maintain insurance meeting all regulatory requirements - which for a WDI business means the errors-and-omissions coverage in OAC 901:5-11-07(C): $100,000 policy general aggregate and $50,000 per occurrence, covering claims arising from errors or omissions in performing WDI diagnostic inspections.

A business whose activities are limited to WDI diagnostic inspections is exempt from the general $300,000 commercial general liability requirement in paragraph (B), but not from paragraph (C).

The Legal Stakes

Because a WDI report drives a real estate closing, Ohio treats dishonesty here severely. ORC 921.24(P) prohibits making a false or misleading statement in an inspection concerning any infestation of pests or the use of pesticides, and ORC 921.99(B) makes that a first-degree misdemeanor on a first offense and a fourth-degree felony on each subsequent offense - the harshest treatment in Ohio's pesticide law.

Test Your Knowledge

Under Ohio rule, which insects are "wood destroying insects"?

A
B
C
D
Test Your Knowledge

A national inspection form's printed instructions conflict with OAC 901:5-11-13 on how to complete a section. What governs an inspection performed in Ohio?

A
B
C
D
Test Your Knowledge

What additional insurance does OAC 901:5-11-07 require of a pesticide business licensed in Category 12?

A
B
C
D