BARLEQUIN BUG 
(M urgarUia histrionica Hahn) 
Life History 
The harlequin bug is a southern plant pest and lives through the 
winter in the adult stage near fields where its food plants are grown. 
The bugs leave their winter quarters early in the spring and seek their 
favorite food plains, which are cabbage, collar d, turnip, horseradish, 
kale, and related crops. The increase in population is started by the 
eggs, which are Laid on the under side of the leaves. These eggs hatch 
in from 4 to 1 "> days, and the young, or nymphs, (vvd and develop on the 
Leaves of the plants, sucking the sap from the leaves and stems. Shortly 
afterward white areas or blotches appear about the spots where the 
feeding has occurred, and the injury often causes the plants to wither 
and die. The insect becomes full-grown in from 40 to 50 days after 
hatching from the egg. The adult, or winged stage, is reached after 
the nymphs have passed through five immature stages, or instars. 
Within 2 or 3 weeks after becoming full-grown the female is ready to 
deposit eggs for another brood. 
Control 
Practice clean cultural methods throughout the season. Disk 
and plow under all stalks and other refuse as soon as the crop has been 
harvested. The growing of trap crops, hand picking, and the use of 
the blow torch are also effective methods of keeping down the number 
of bugs. 
Control by insecticides is recommended only after preventive 
measures to reduce the numbers of the insect have been followed. 
Spray or dust with derris or cube. 
Use Iji pounds of derris or cube root powder (containing 4 percent 
of rotenone) with a spreader and wetting agent in 50 gallons of water; 
or, in smaller quantities, 1% ounces (10 level tablespoont'uls) with a 
spreader and wetting agent in 3 gallons of water. 
For dusting, use a derris or cube dust containing 0.7"> percent 
of rotenone. To prepare this dust, use 15 ounces of finely ground 
root (having a 4-percent rotenone content) to 4 pounds and 1 ounce 
of the diluent (finely ground talc, clay, sulfur, tobacco, or other powder 
except lime), or 18% pounds of the root to 81% pounds of the diluent. 
If the rotenone content of the derris or cube is greater or less than 4 
percent, then the proportions of the inert diluent must be varied 
accordingly. 
Begin spraying or dusting when the bugs first appear and repeat 
the treatments as often as necessary. 10— isssa 
March 1940 U.S. Government Printing Office 
i e by the Superintendent <>f Documents, Washington, D. ('. Price 5 cents 
UNIVERSITY OF FLORIDA 
3 1262 09082 4805 
