8 CIRCULAR 418, U. S. DEPT. OF AGRICULTURE 



in the field feeding on a bean beetle larva. Adults of H. pennsyl- 

 vcmicws were taken by Miller (15) in Ohio feeding on young larvae 

 on the ground and on plants. 



The average number of hosts consumed per day by those species 

 found at Birmingham as compared with Calosoma Jaeve Chev., a 

 carabid which feeds on the bean beetle at Mexico City (16), is given 

 in table 5. 



Table 5. — Food consumed daily oy species of caraoids in confinement at Bir- 

 mingham. Ala., compared with the daily feeding of Calosoma laere at Mexico 

 City. Mexico 





Stage of 

 carabid 



Average hosts eaten per day- 



Species 



First 

 instar 



Second 

 instar 



Third 

 instar 



Fourth 

 instar 



Pupae 



Adults . 



Scarites subterraneus 



Larva 



Adult 



do 



do 



Nu mber 

 14.81 

 16.24 

 2.51 

 58.24 



Number 



7.41 



8.12 



1.26 



29.12 



Number 



3.70 



4.06 



.63 



14.56 



Nu mber 



0.74 



.81 



.13 



2.91 



Number 



0.93 



1.02 



.16 



3.64 



Nu mber 

 1.24 

 1.35 



Harpalus caliginosus 



Calosoma laeve 



.21 

 4.85 



Two tiger beetles, Tetraclia Carolina and T. virginica, in both larval 

 and adult stages consumed large numbers of larvae, pupae, and 

 adults of the bean beetle in confinement at Birmingham. Eggs 

 were not consumed when other food was present. It is questionable 

 whether these tiger beetles are of much importance in the field 

 (9, IB). 



Adults of Tetraclia Carolina lived 35 days and of T. mrginica 27 

 days in the insectary. The average quantity of food eaten per day 

 during confinement is shown in table 6. 



Table 6. — Food eaten daily oy adult Tetraclia Carolina and T. mrginica confined 



in an inseetaru 





Average hosts eaten per day 



Species 



Eggs 



First 

 instar 



Second 

 instar 



Third 

 instar 



Fourth 

 instar 



Pupa 



Adults 



Tetracha Carolina 



Number 



20.33 

 25.34 



Number 

 12.20 

 15.22 



Number 

 6.10 

 7.61 



Number 

 3.05 



3.81 



Number 



0.61 



.76 



Number 



0.76 



.95 



Number 

 1.02 





1.27 







HEMIPTERA 



A small anthocorid bug, Orius imidiosus, observed by Jones in 

 Ohio, was found feeding on probably 4 percent of the pupae late in 

 June. 



Two species of Nabidae, Nabis ferns and N. roseipennis, were ob- 

 served feeding on eggs and young larvae of the bean beetle at Colum- 

 bus. Ohio, in 1924, by D. M. DeLong. 



The wheel bug, Arilus cristatus, consumed large numbers of bean 

 beetles in confinement at Birmingham, Ala. One adult lived 88 days 

 and drained the contents from 60 individual hosts, most of which 



