INDIANAPOLIS (AP) — Indiana officials say the problem with an invasive, tree-killing disease called sudden oak death is worse than initially suspected.

The state Department of Natural Resources said last week the fungal pathogen was detected in rhododendrons at about 30 stores. The Indianapolis Star reports Wednesday the number has since tripled, and affected material was sent to more than 70 Walmart stores and 18 Rural King stores in Indiana.

Megan Abraham, director of the DNR’s Division of Entomology & Plant Pathology, says the plants were delivered to several other states, but she didn’t specify which ones. Abraham says Indiana has the most locations with infested plants.

The DNR has said that it’s the first time in about 10 years that sudden oak death has been detected in Indiana.