Good afternoon,

I just wanted to share with you some information I have received regarding Spongy Moth Caterpillars. I have received several calls recently and I have since reached out to our DNR partners.  MSU Extension is also a great resource for this as well (Thanks Julie!).  Some items I received from the DNR are below:

  • The DNR does not have a spray program for spongy moth caterpillars. There are natural enemies of the spongy moth that are now well-established across Michigan and are actively reducing populations. To date, these pathogens typically have limited the size and length of outbreaks to a couple years, eliminating the need for spray programs.
  • Nucleopolyhedrosis virus occurs naturally in all spongy moth populations. In addition, suppression efforts in the 1990s using the fungal pathogen Entomophaga maimaiga have continued to keep spongy moth populations largely in check while naturalizing infestations into Michigan’s forests and urban forest ecosystems.


  • Nobody enjoys outbreaks of spongy moth caterpillars, as they are a nuisance if you want to be outdoors. The recommendations provided in the attached press release provide ways to limit this nuisance as much as possible during peak populations, which Kalamazoo is experiencing now. Please also note that though many folks are concerned about damage to trees, most deciduous trees will re-leaf later in the summer (more information is available in the press release).

A few other links are below as well:

DNR Information: 

MSU information:


Have a great day!


Lucus Pols, REHS
Environmental Health Division Manager
Health & Community Services


o. 269-373-5356


311 E. Alcott St., Kalamazoo, MI 49001