16 BULLETIN 1243, U. S. DEPARTMENT OP AGRICULTURE. 



observed to feed voluntarily on many plants, especially when their 

 favorite food has been destroyed or has become scarce. Among 

 these plants are the following: Velvet bean, kudzu, crimson clover, 

 white clover (PL IX, B), corn, grasses, okra (PL VIII, A), eggplant, 

 potato, squash, mung bean (Phaseolus aureus), and weeds. None 

 of these plants has ever been severely damaged. Adults have also 

 been taken feeding on Galactia volubilis and Lespedeza virginica. In 

 the fall volunteer feeding on kudzu is not uncommon, while trials 

 earlier in the year to breed the insect on this host have been fruitless. 

 Feeding on mung bean (Phaseolus aureus) is very rare, and only 

 one instance of feeding on wild morning-glory (Ipomoea sp.) has been 

 observed, under unusual conditions. The insect does not normally 

 feed on sweet potato or peanut. Information relative to the prefer- 

 ence of the beetle for snap beans, both pole and bush, compared with 

 Lima beans, cowpeas, and soy beans, may be gained from the reports 

 on field scouting, most of which was done in sections where infestation 

 was light. These reports show a decided preference of the beetle for 

 the garden bean over the Lima bean, that the cowpea is far removed 

 from either of these, and that the latter is preferred to soy bean. In 

 south Georgia beggarweed (Meibomia tortuosa) is preferred to cow- 

 pea, this plant being infested with all stages of the insect when cowpea 

 is scarcely infested. 



The problem of food plants of the Mexican bean beetle is not the 

 same in the Southeast as in the West and Southwest. Not only does 

 the problem concern the grower of susceptible crops, but it has an 

 important bearing on the policy to be followed regarding quarantine 

 and extermination policies. The fact that a number of new food 

 plants came under observation immediately after investigation of the 

 problem is evidently explained by the fact that the insect acts differ- 

 ently under new climatic conditions. Obviously, also, some appar- 

 ently new habits may be of old standing. 



Soon after the avidity of the beetle for beggarweed or beggartick 

 (Meibomia tortuosa) in southern Georgia was reported by Luther 

 Brown, the same facts were independently discovered in Mexico by 

 Prof. H. F. Wickham, while employed by the Bureau of Entomology. 

 Similar observations were made in northern Alabama by J. R. 

 Douglass and the writers and subsequently in Mexico in 1922 by 

 E. G. Smyth. It is therefore probable that Meibomia has been a host 

 plant for many years. In 1920, when the bean beetle was first 

 reported in northern Alabama, cowpea and soy bean were observed 

 as food plants. Adults were first observed feeding on soy bean, in 

 Colorado, by A. E. Mallory, Bureau of Entomology, in 1919. The 

 greater variety and accessibility of leguminous food plants in the 

 southeastern part of the United States, together with the abnormal 

 abundance of the insect, has probably been the chief cause of changes 

 of habit and new observations of old habits. In trucking sections 

 in the Southeast cowpeas are often raised as a truck crop for human 

 consumption in the green stage. In many such instances severe 

 damage has been done to this crop. In a number of cases marked 

 injury to fields of cowpea of considerable size has occurred, but 

 always in a section where the infestation on garden beans has been 

 extremely heavy. 



A decided preference is shown by the Mexican bean beetle for 

 "pinto" and tepary beans. In 1921 pinto, or Rosello spotted, beans 



