26 BULLETIN 1243, U. S. DEPARTMENT OF AGRICULTURE. 
will no doubt require many years for native enemies to become adapted 
to it. No insect or other enemy has been observed to effect any 
appreciable control in the western part of the United States. 
PREDACIOUS ENEMIES. 
The following predacious insect enemies have been observed to 
prey on the Mexican bean beetle, Hpilachna corrupta, in the field, and 
most of these have been observed in confinement. 
The common coccinellid beetle, Megilla maculata DeG., was very 
abundant about Birmingham, Ala., during the summer of 1921. 
This beneficial species fed, in both the larval and adult stages, on 
the eggs of the bean beetle, and occasionally on young larve. Many 
ege masses were attacked and a few eggs of each destroyed. The 
bean beetle was so abundant that less than 3 per cent of the eggs 
were destroyed. During 1922 Megilla was not abundant, and very 
few eggs were destroyed. 
The convergent lady-beetle Hippodamia convergens Guér., also eats 
the eggs of the bean beetle, but sparingly. The adults of Coccinella 
sanguinea L. and C. novemnotata HUbst. feed slightly on the eggs, the 
latter species more generally on younger larve. Adalia bipunctata 
L. feeds slightly on the eggs and small larve. 
A common soldier-bug, Stiretrus anchorago Fab., destroys larve, 
pup, and beetles. It is not common until late in the season, and 
then is not sufficiently abundant to be of much value. This bug, 
both in the last nymphal and in the adult stages, is at present the 
most effective native enemy. 
Another pentatomid bug, Podisus maculiventris Say, feeds in both 
nymphal and adult stages on larve, pup, and adults of the bean 
beetle and is a more active feeder than Stiretrus. It is not generally 
as numerous as Stiretrus, and is therefore less effective. Both of 
these bugs can subsist for long periods on a bean beetle diet. 
The common wheel-bug, Arilus cristatus L., feeds on larve, pupe, 
and beetles, but is too rare to be effective. 
The ground beetles might be expected to prey on the bean beetle, 
especially when the latter is so abundant as to destroy a field of beans 
and the larve crawl about in search of food. No beneficial effects 
have been observed from this source, though three native species, 
Harpalus caliginosus Fab., Scarites subterraneus Fab., and Caloserl 
sayi Dej., eat larvee sparingly, and the latter two species attack 
pupz and beetles in confinement. 
The tiger beetles Tetracha carolina L., and T. virginica L., both 
larvee and adults, feed voraciously in confinement on larve, pupe, 
and adults of the bean beetle and occur in infested fields. It is not 
certain that they feed voluntarily on this insect in nature, and their 
habits would not indicate that they are very important enemies. 
They are not present in numbers in well-cultivated fields. 
The larvee and adults of the lace-wing flies Chrysopa oculata Say 
and C. rufilabris Burm. feed on pup of the bean beetle. They are 
not numerous and are of little importance. 
In the fall of 1921 a number of instances of feeding by one 
on pup of the bean beetle were noted. In three instances the larve 
matured in confinement on a diet of bean-beetle pupxw and developed 
into normal moths, two of which were identified by Dr. F. H. Chitten- 
den as Prodenia ornithogallt Guen., and the third as Laphygma 
