GLADIOLUS THRIPS 
( Taeniothrips simplex Mor. ) 
ES- 
Gladiolus thrips overwinter and may reproduce on the stored 
gladiolus corms. During the growing season the adults and larvae 
attack the foliage and flowers of the growing plant. The eggs are 
inserted into the plant tissue. In the summer a generation of the 
thrips may be completed in 2 weeks. 
The gladiolus thrips can be controlled by applying DDT to the 
stored corms or the growing plants. 
Treatment of the Corms 
On dormant corms use a 5-percent DDT dust. Apply 1 ounce of 
dust per bushel of corms in trays or 1 teaspoonful per 100 corms in 
paper sacks. Apply the dust with a duster over the top of filled 
trays soon after the corms are harvested or after cleaning. It is 
important to destroy the thrips before they penetrate beneath the 
protecting scales. 
Control on the Plants 
Watch the growing plants for evidence of thrips feeding. If you 
observe such feeding, spray or dust with DDT at once and continue 
at weekly intervals until the flowers appear. If infested plants are 
not treated until they bloom, the flowers cannot be saved from 
disfigurement. 
Apply the spray as a fine mist, and avoid run-off. For spraying a 
few plants use 1 ounce, or 6 tablespoonfuls, of 50-percent DDT wet- 
table powder to 8 gallons of water ; for larger quantities use 2 pounds 
to 100 gallons oi water. 
If you use a dust, it should contain 5 percent of DDT. Apply it 
lightly and evenly over the plant. 
CAUTION. — Insecticides are poisonous and should he 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 
