Avoid falling for tree and shrub pest control scams

The following article was released by Michigan State Extension this week. It is the result of a complaint from a certain tree-care worker who was getting tired of responding to calls from worried customers. The customers had been advised by a mega-lawn-care representative that their trees/shrubs had pest issues requiring multiple spray applications. Said tree-care worker had to drive around town, checking the trees, and assuring the customers that there was no issue:


Posted on July 28, 2015 by David Smitley, Michigan State University Extension, Department of Entomology

It looks like we are seeing a new pesticide treatment sales scam. Most of the complaints so far are from Michigan’s Ann Arbor-Ypsilanti area, although everyone should be alert for this scam that involves a scare tactic about a non-existent or unimportant pest.

It works like this: A sales representative from a lawn, tree and shrub care company visits your yard and fills out a report. On the report, spider mites or another pest is circled and a warning is hand-written, “Spider mites are damaging your trees. A miticide treatment is highly recommended.”

The reason a scam is suspected is because one arborist in the Ann Arbor, Michigan, area has had six of his customers call him after they received this warning. When he investigated, he could not find any spider mites or damage at any of the six locations. Sometimes the sales person will leave a little Zip-lock bag with the report, like they did at my house about 15 years ago. It contained a leaf with a hole in it, and the warning, “You have gypsy moth. A spray is highly recommended.” When I looked at my trees, I had a difficult time finding any leaves with holes in them, and when I did, it was caused by a cankerworm, not gypsy moth.

A few holes in tree leaves are completely harmless. In fact, a pesticide spray would probably cause more harm than good because it will disrupt the predators and parasites providing natural control. We don’t usually see problems with spider mites in the yard and garden unless an insecticide, like carbaryl, is being sprayed. Carbaryl and some other insecticides can kill the predators that usually keep spider mites under control, but spider mites may be resistant to the insecticide and thrive in the absence of predators.

Arborists and responsible landscapers dread hearing about this type of scam because it makes their industry look bad. This is very unfair to a landscaping and tree care industry consisting of 99.5 percent responsible business owners. In fact, the last time we had this type of scam, the local branch manager of the company promoting the scam said it was due to a “rogue employee” that had not completed training and was going against their company policy. In my opinion, if a sales representative finds 10 customers in one neighborhood that have spider mite damage, the manager should investigate to see if this is a real or imaginary problem.

spider_mite_damage1_roses_Univ_Calif If you are looking for real spider mite problems, read “Pests in Gardens and Landscapes: Spider Mites” from UC Davis, and see the attached pictures.



Spider mite damage in roses. Photo by UC Statewide IPM Project