Landlord Liability for Bedbugs - Milwaukee

[John Franczyk]

I'm doing due diligence on a multi-unit building in Milwaukee. At least one existing tenant has complained of bedbugs previously and the property manager applied pesticide in his and one other unit about two months ago. The tenant washed all of his clothing and linens, bagged up his mattresses and box springs in sealed casings, and applied diatomaceous earth around all parts of his apartment at this cost. The tenant just complained that the bedbugs are back and is insisting that he is not the source, but that the building has an infestation problem.

Is a landlord liable for bedbug problems in a multi-unit (i.e. more than 4 apartments) building? What expenses are the Landlord's and what expenses are the tenant's? The lease is silent on this issue.

Thanks for any guidance or anecdotes.