Knowledgebase
What is this grub eating my poor roots! #449052
Asked April 22, 2018, 10:59 PM EDT
Washington County Oregon
Expert Response
Thank you for the excellent images.
The critter on your palm is a crane fly larvae. Even though they may be found in the soil of both lawns and garden beds, they are seldom a significant problem. You can dispatch them as you find them – putting them in slightly soapy water works well.
I am a bit more concerned about identifying the snails in the white pan. They look suspiciously like brown garden snails, Cantareus aspersus, formerly Helix aspersa. Invasive creatures which eat a wide variety of garden plants, both ornamental and edible. “Snails and Slugs” describes these snails and discusses management in home gardens. (http://ipm.ucanr.edu/QT/snailsslugscard.html ) If you have any questions as to the correct ID for the snails in your image, please send me close-ups of both sides of the shells.
I've posted an image of the brown garden snail with this email. (Photo by Jack Kelly Clark.)
In spite of the rumors you may have heard, crane fly larvae (leatherjackets) are seldom a problem in gardens.
To be blunt, my 35 years of experience with brown garden
snails (in Southern California) tells me you should worry about them.
Copper strips can exclude snails from a garden but only if the bands are 4-inches wide. Another requirement is make certain that plant materials don’t create easy “snail highways” into the garden area by flopping over the edge.
If the leatherjackets were in a lawn, the level to begin treatment is 50 per square foot. How many do you have?