Spittlebugs Galore–Garden Pests

Seaholly covered in foamy liquid that protects juvenile spittle bugs

Most of the time in the late spring when the spittlebugs are on my garden plants, I don’t pay them any notice.  They normally show up on tender new shoots in April or May.  Of course, the dripping, foaming mass that the young spittlebug nymphs hide in while feeding on plant juices is unmistakable, but they do so little harm.  If I think about it and have a hose handy, I’ll rinse them off the plant.  This year, however, they seem to be more plentiful than normal.  Others have told me they’ve seen more than usual, as well.

Spittlebug nymph on underside of Monarda leaf

Spittlebug or froghoppers (Philaenus spumarius) feed on a variety of plants, from grasses to strawberries to perennials–their favorite place to hide is the leaf axil where the leaf meets the stem.  In my experience  they enjoy asters and others in the composite family.  This year, they have developed a taste for Eryngium (seaholly), Italian parsley and Monarda (bee balm), among other plants.

At times the only result of their feeding is some stunted, twisted stems that are easy to prune out, leaving no lasting damage. Spittle bugs only have one generation a year, so once they are fully grown adults in summer, any damage seems to subside, though adults do continue to feed on plant juices.  They go on to lay their eggs in the fall and those are the eggs that will hatch the following spring.  It will be interesting to note with the higher population of nymphs I am seeing now (which look just like the adults, only softer, shinier and pale green or yellow) if the summer damage I see from adults will be greater, too.

Stem of seaholly has collapsed from damage at at leaf axil

Since they are so plentiful this year, I have noticed more damage than usual, including collapsed flower stems and severely distorted foliage.  The nymphs feed for 6-7 weeks before reaching adulthood, when they can then jump and fly readily.  So squishing the nymphs and rinsing them off plants now is the easiest control method.  Since the adults are mobile, they can’t be controlled that easily and dispensing with the nymphs will keep them from laying eggs for next year.

Distortion and discoloring of Monarda foliage

The research indicates that the above tactic is the best control since any chemical sprays effective on spittlebugs must be applied BEFORE the spittle masses appear–too late now by almost a month (the spittle protects them from the chemicals).  Not to mention that the sprays labeled for them are quite toxic to bees, so much so that their usage on flowering plants (like strawberry) is recommended only well before any flowers open.

According to WSU’s “Hortsense” website reference to spittlebugs on strawberries, yellow jackets and other predators may pray on them.  It’s one of the reasons yellow jackets, while admittedly not my favorite garden visitors, are good to have around.

Parsley flower and spittle mass

So, out to the garden I go, hose in hand, to rinse off the spittlebugs every two or three days so that next year’s population isn’t so dramatic.   And next spring, I’ll be more diligent than I have been to do the same as soon as I see the white foam appear in the garden rather than once I see the resulting damage.

Washington State University Hortsense Website:

http://pep.wsu.edu/hortsense/scripts/query/displayProblem.asp?tableName=plant&problemID=152&categoryID=2

© Colleen Miko, 2012

About Colleen Miko

Colleen Miko is a certified professional horticulturist with 20+ years experience in landscape design who has designed award winning gardens for the NW Flower & Garden Show as well as HGTV’s “Landscaper’s Challenge”.
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