10 CIRCULAR 418, IT. S. DEPT. OF AGRICULTURE 



a day for the first 4 to 6 days, but took little or no food for the 

 4 or more days preceding the molt to the adult stage. 



A total of 23 nymphs of Podisus maculiventris were reared from 

 egg to adult on larvae and pupae of the bean beetle at Columbus, 

 Ohio, at a cabinet temperature of approximately 70° F. The average 

 length of the developmental stages are as follows : Egg 5 days, first* 

 instar nymph 3 days, second-instar 4 days, third-instar 4.1 days, 

 fourth-instar 6.3 days, and fifth-instar nymph 10.7 days. 



Perillus hioculatus is found occasionally in bean fields in Ohio. 

 Jones 3 reports it as feeding to a slight extent on immature stages 



Figuke .3. — The spiiied soldier bug (Podisus maculiventris) leeding on a larva of the 



Mexican bean beetle. 



of the bean beetle. Efforts to rear P. hioculatus in the laboratory 

 beginning with the second instar (first carnivorous stage) either on 

 eggs or larvae of the bean beetle were unsuccessful. Unlike nymphs 

 of Podisus maculiventris, nymphs of Perillus hioculatus fed when 

 bean beetle eggs alone were supplied and occasionally molted into 

 fourth-instar nymphs before dying. It appears probable that P. 

 hioculatus is attracted to bean fields by the presence of insects other 

 than the bean beetle. 



Perillus circumcinctus killed and partly consumed adult bean 

 beetles in cage tests conducted by Stehr and Farrell (17) at Athens, 

 Ohio, in 1933. 



Acrosternum Mlaris and Nezara viridula, two pentatomids which 

 have been considered generally to be plant feeders, have been ob- 

 served feeding on stages of the bean beetle. 



Acrosternum hilaris has been taken several times in Connecticut 

 feeding on larvae and pupae (8). Four adults observed feeding on 

 bean beetle eggs in the field at Birmingham, Ala., were confined in 

 the insectary where each adult consumed approximately 15 bean 

 beetle eggs per day. One adult lived for 25 days in the insectary. 



Nezara viridula nymphs, in Ohio, have been observed puncturing 

 most of the eggs of several masses near their base and withdrawing 

 the contents (15). 



3 Jones, M. P. a two-yeaks' study of the biology and control of the Mexican 

 bean beetle (EPILachna corrupta) in Ohio. 1925. (Unpublished manuscript.) 



