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lawn grubs

Q: When I lived in Ohio, I used Milky Spore to control grubs in my lawn.  Will it work here in Fernandina on my St. Augustine grass?

Q: When I lived in Ohio, I used Milky Spore to control grubs in my lawn.  Will it work here in Fernandina on my St. Augustine grass?  If so, when is best time to apply?

A:  Thank you for writing.  I checked with the University of Florida Entomology Department for their expertise on this topic.  Milky spore is used on Japanese beetles and apparently has only shown minimal success.  Milky spore is a bacterium ( Bacillus popilliae) which is produced by a technical in vivo culture procedure using the larvae and adults of Japanese beetles.  It is host specific, which means it works only on Japanese beetles.  We, thankfully, don’t have Japanese beetles in Florida.  Therefore, it would be of little use here to fight lawn grubs.

Are you certain grubs are a true problem in your lawn?  To inspect for grubs, cut 3 sides of a 1 foot square piece of sod and roll it back.  Sift through the sod to see if grubs are present.  Inspect several areas.  As a rule of thumb, if an average of 3 or 4 grubs are found per square foot, then apply insecticide.  There are plenty of products on the market to fight the grub population just be sure they can be applied to St. Augustine grass and follow the directions on the label.