Description
The adults are heavy-bodied, wedge-shaped insects about a quarter
of an inch long. They are usually a mottled brown and cream,
but vary from cream to almost black. They jump readily, making
an audible thump. The eggs are small, yellow-to-white, elongate
capsules laid in rows in a matrix under the leaf sheaths of
grain stubble and in similar places. The young (nymphs) are
yellow to orange. The nymphs cause the damage. They are found
behind leaf sheaths, in folded leaves, or on the leaves and
stems in masses of froth or spittle during late April, May,
and early June. Both the nymphs and the adults may be found
on a wide variety of weeds and plants, but they concentrate
chiefly in alfalfa and clover fields. |
Click
on image for larger version
Figure 1. Meadow Spittlebug Nymph
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Figure
2. Meadow Spittlebug
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Life
Cycle
There is one generation each year. The insect overwinters in
the egg stage. The eggs hatch in early to mid-April in central
Illinois, and the last two weeks in April in northern Illinois.
After the tiny nymphs hatch, they immediately start to suck
sap from the plant and form the froth in which they live. At
first, they are found in the crowns and the folded leaves of
the plants; later, in large masses of froth anywhere on the
plant. From one to several nymphs may be found in a mass of
froth. The nymphs mature in June. The adults feed on a variety
of plants until late August, when they congregate in clover
and alfalfa fields to lay their eggs. Egg-laying continues through
September. |
Damage
When abundant, spittlebugs stunt plant growth by suncking the sap.
They may cause losses in yield varying from slight to 25 percent
or more. An average of 1 nymph per stem can decrease the yield of
dry hay by 300 or more pounds per acre. To determine the need for
treatment, count the spittlebugs on 50 to 100 stems selected throughout
the field.
Control
Chemical control is usually not profitable if the number of
spittlebug nymphs averages fewer than I per stem. When the average
is 1 or more nymphs per stem, control will be profitable if
you need the hay. |
Click
on image for larger version
Figure
3. Meadow Spittlebug on Mass of Froth
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Authors:
Susan T. Ratcliffe (sratclif@uiuc.edu)
Michael E. Gray (m-gray4@uiuc.edu)
Kevin L. Steffey (ksteffey@uiuc.edu)
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