28 BULLETIN 1243, U. S. DEPARTMENT OF AGRICULTURE. 
host was hibernating as an adult, and this habit may make coloniza- — 
tion difficult. This parasite appears to be capable of immense — 
benefit. t 
Phytophagous Coccinellidae in Java, according to Dr. P. van der © 
Goot, entomologist to the Dutch Government, are attacked in the ~ 
ego, larva, and pupa stages by Hymenoptera; hence it appears that 
other parasites that may prove useful against Epilachna corrupta 
may be found. 
EFFECT OF SUNLIGHT. 
During a prolonged hot dry period in 1921, when bean beetles were 
so numerous that they destroyed all bean plantings in the Birmingham 
district, the larve were forced to crawl about in search of food, and 
were also exposed to the sun on the stems and stalks of plants. Pupe 
were so numerous that many stalks and pods were literally covered 
with them, and many larve pupated on the ground, or on stones, 
weeds, or any object at hand. Many thousands of pupe gradually 
turned brown and died. 
Experiments were performed and various stages of the insect were 
exposed to sunlight. The eggs, which are normally protected from 
direct sunlight, are neal y laid on the upper surface of the leaf, 
or, when laid on the under surface, may be exposed in some in- 
stances by bean leaves growing upward. This is often the case with 
the tepary bean. An exposure to sunlight for 33 hours on four con- 
secutive days in June killed 57 eggs when the shade temperature 
ranged from 74° to 94° F., but 15 eggs of a group of 59 hatched after 
30 hours’ exposure on the same days. Twenty-four groups, totaling 
1,240 eggs, exposed to the sun continuously from three to five days 
during late July and August at shade temperatures reaching a maxi- 
mum of from 80° to 101° F., succumbed with the exception of two 
eggs. 
“An exposure to direct sunlight for two minutes was fatal to first- 
instar larve 1 day old when shade temperatures registered 96° F. 
Second-instar larve, 5 days old, succumbed after seven minutes’ 
exposure to direct sunlight when the shade temperature registered 
92° F. Third-instar and fourth-instar larve succumbed after 10 
minutes’ exposure to direct sunlight when the shade temperature 
registered 93° F. 
Three hundred pup were collected in the field September 12 and 
exposed to the sun for two days when maximum shade temperatures 
each day registered 96° F., and all succumbed, while 78 per cent of 
a check of 100 pupze emerged in the shade, and all pup reared in 
the shade in other experiments emerged. Undoubtedly most of the 
22 per cent of pupe of the check lot had been killed by sunlight in the 
field. 
Adults are more resistant, and since they can fly to sheltered 
places are not usually killed by effect of sunlight. Under conditions 
of light or medium infestation, large numbers of the various stages 
of the insect are not exposed and no great benefit from this source 
occurs. Allin all, however, the factors enumerated above, and no 
doubt others which were not observed, tended to reduce the 
number of adults going into hibernation to such an extent that the 
infestation was much lighter in 1922 than in 1921. 
