V 
 
 MEXICAN 
 BEAN BEETLE 
 
 «« 
 
 %• 
 
 a 
 
 ** d 
 
 a, Adult beetle; b, eggs; r, larva; d, pupa (or resting stage); 
 e, bean leaf showing typical feeding injury. (About 2'_. times 
 natural size. 
 
 • other Bide for life history and control) 
 
 Unite : ~ 
 
 Picture Sheet 
 
MEXICAN BEAN BEETLE 
 
 i Epilael Muls.) 
 
 Life History 
 
 The Mexican bean beetles overwinter in the adult or beetle 
 stage, usually in woodlands Dear bean fields. They leave their win- 
 ter quarters in the spring, and the female beetles lay their eggs on 
 the under side of the bean leaves. These eggs hatch in from 5 t<> 1 1 
 days. The resulting larvae feed principally on the under side of the 
 bean leaves. The larva grows rapidly, passing through four differ- 
 ent stages, or Instars, similar in appearance except that each stage 
 is larger than the preceding one. It reaches full growth in from 20 
 days to 5 weeks. When full-grown the larva attaches itself to the 
 under surface of the leaf on which it has been feeding, or to some 
 nearby plant or object, and changes to the pupa or inactive stage. 
 After a period of about 10 days the adult beetle emerges from the 
 pupa. Within '1 weeks the female beetle is ready to deposit eggs for 
 another brood. 
 
 Control 
 
 Spray or dust with derris, cube, or cryolite. Any of the follow- 
 ing insecticides applied to the beans so as to rover flu under sicL 
 the leaves thoroughly will protect the plants (spraying has given 
 better results than dusting). 
 
 Sprays 
 
 To prepare a derris or cube spray, use finely ground derris or 
 cube root (4-percent rotenone content) at the rate of one-half ounce 
 (3 level tablespoonfuls) to 1 gallon of water; or l 1 •> ounces (10 level 
 tablespoonfuls) to 3 gallons; or li/> pounds to 50 gallons. 
 
 To prepare a cryolite spray, use 1 ounce (3 level tablespoonfuls) 
 of cryolite to 1 gallon of water; or 3 ounces (9 level tablespoonfuls) 
 to 3 gallons ; or 3 pounds to 50 gallons. 
 
 Dusts 
 
 To prepare a derris or cube dust, containing 0.5 percent of rote- 
 none, use 10 ounces of finely ground derris or cube root (4-percent 
 rotenone content) to 4 pounds 6 ounces of diluent (finely ground talc, 
 clay, sulphur, tobacco, gypsum, or other powder, except lime) ; or 
 1 2 1 L . pounds to 87 ] L » pounds of the diluent. 
 
 "To prepare a cryolite dust, use 3 pounds of cryolite to 2 pounds 
 of diluent (finely ground talc or sulphur) ; or 60 pounds of cryolite 
 to 1<> pounds of the diluent. 
 
 The first application of insecticide (spray or dust) should be 
 made when Mexican bean beetles are found in the field or when eggs 
 become numerous on the under side of the leaves. Repeat every 
 week or 10 days if the insects are numerous. 
 
 Caution: Cryolite should not be applied to beans alter the pods 
 begin to form. 
 
 UNIVERSITY OF FLORIDA i l0790 
 
 III 
 
 3 1262 09082 4813 
 Juno U. S. Government Printing Office 
 
 For sale by the Superintendent of Documents, Washington, D. C. — Price 5 cents