These articles are written to apply to the northeastern
corner of Illinois. Problems and timing may not apply outside of this
area. |
That's Not Spit on That Plant!
June 10, 1999
Noticed what looks like spit on a variety of plants lately? Thats
not actually spit, but the work of the spittlebug. Both the meadow spittlebug
and pine spittlebug can be found in our area. A glob of what looks like
white spit, called spittle, is the telltale sign of this insect.
If you carefully remove the spittle, you will find the insect inside.
Spittlebug nymphs feed on plant sap and are protected by enclosing themselves
in the frothy spittle, and may stay there for up to 7 weeks. Spittlebug
adults are about 3/8 inch long, elongate to oval in shape, and usually
some shade of brown. They will emerge from the spittle and look like a
leafhopper.
Spittlebugs overwinter as eggs on the stem of the host plant. After hatching
and feeding, nymphs secrete the frothy liquid and cover themselves. When
the nymph has developed into the adult, it will emerge from the spittle.
Meadow spittlebugs may be found on many species of flowers, weeds, clover,
arborvitae, and strawberries. Nymphs found in the froth will be green.
Other than being unsightly, meadow spittlebug rarely occurs in large enough
numbers to cause serious damage. Washing them off with a forceful stream
of water is a control option. Keeping down weed populations near garden
areas may help reduce numbers, particularly near strawberry plantings.
Pine spittlebug will feed on Scots, Austrian, and white pines; along
with spruces and firs. Nymphs of pine spittlebug are brown. Heavy populations
may be more of a serious problem, as sap flow can be reduced. In addition,
wounds made by feeding can be entrance points for diplodia shoot blight
disease. Diplodia is a fungus that can cause dieback of shoots on pines.
Pine spittlebug can be controlled using insecticides such as acephate
(Orthene), carbaryl (Sevin), or dimethoate (Cygon). A forceful spray may
be required. Read and follow all label directions. So next time you see the white foam of this insect, think of the clever
way it is protecting itself. And if numbers are high, you may need to
think of control measures. |