STRIPED CUCUMBER BEETLE 
( Acalymma vittata (F.) ) 
The striped cucumber beetle is one of the most familiar insects to gardeners 
in the Eastern and Central States. It is also one of the most troublesome. The 
beetles invade cucumber, squash, and melon plantings almost overnight, and 
often destroy tiny seedlings before they push through the soil. They girdle 
stems of older plants, and eat portions of the leaves. They also transmit 
bacterial wilt and mosaic disease from plant to plant. The grubs, or larvae, 
live on the roots and reduce the vitality of the plants. 
The adult beetles spend the winter in uncultivated areas, protected by plant 
debris. In the spring they become active, feeding on some wild plants about 
the time apple trees are in bloom. As soon as the first melon, cucumber, squash, 
or pumpkin seedlings push through the soil, the beetles attack them. Here 
they feed first on the stems and cotyledons, oftentimes killing the plants. There 
may be an influx of beetles into the field for several weeks. As the plants grow, 
the beetles collect under the vines and feed on the lower surfaces of the plants. 
Females crawl into cracks in the soil and deposit eggs. The young larvae, or 
grubs, that hatch from these eggs feed on the plant roots for about a month, 
pupate in the soil, and emerge as adults of the next generation. 
Control 
Several insecticides are effective, however, provided they reach the beetles 
in time. Derris or cube and cryolite are recommended for this purpose. They 
may be applied either as dusts or as sprays to prevent plants from becoming 
infected by wilt. 
The derris or cube dust should contain 0.75 to 1 percent of rotenone, and the 
cryolite dust 40 to 50 percent of sodium fluoaluminate. They are usually 
obtainable at these strengths from local dealers. 
Sprays can be prepared from undiluted powdered derris or cube, which con- 
tains from 3 to ,5 percent of rotenone, or from a rotenone-containing extract. 
Use enough of the powder to give a spray containing 0.02 percent of rotenone. 
This requires 5 1 /. pounds of a powder containing 3 percent of rotenone, or 4 
pounds of one containing 4 percent, in 100 gallons of water. Use the rotenone- 
containing extract at the strength recommended by the manufacturer. To pre- 
pare a cryolite spray use 5 pounds of cryolite containing 90 percent of sodium 
fluoaluminate or its equivalent in 100 gallons of water. 
Apply the dusts at 15 to 30 pounds per acre and the sprays at 75 to 100 gallons 
per acre, the rate depending on the size of the plants. To be effective the 
applications must be timely, thorough, and frequent. Keep in mind the follow- 
ing points : 
( 1 ) Protect the young seedlings. 
(2) Apply the dust or spray to the plants as soon as the beetles appear. 
(3) Apply a light, even coating over the entire plant, especially at the 
point where the stems emerge from the soil. 
(4) Repeat the applications after rains and as often as necessary to keep 
the plants free from the beetles. 
CAUTION. — Insecticides are poisonous and should be handled with care. 
10 — 20760-1 
Issued April 1941 
Revised June 1950 U. S. Government Printing Office 
For sale by the Superintendent of Documents, Washington, D. C. — Price 5 cents 
