THE MELOK fly. 25 
longevity of the adult. Since one female fly has been known to live 
431 days, it is evident that the complete life cycle from the laying of 
the egg to the death of the fly may be 443 to 460 days when the im- 
mature stages are passed during the warmer portions of the year. 
At an average mean temperature of about 68° F., which is the coolest 
temperature found in Hawaii where fruits are available in numbers 
for study, the immature stages are passed in 40 to 45 days. It is 
difficult to state just what the variation in the life cycle may be in 
colder climates, but it may range between 3 and 4 months. 
This rapidity of increase throughout the coastal regions permits 
from 8 to 11 generations of the melon fly a year, when a generation is 
considered to extend from the time the egg is laid until the female of 
the next generation begins to deposit eggs. As the females are 
capable of living" many months and of depositing eggs at frequent 
intervals throughout life, the generations become hopelessly mixed. 
It is possible for a female ovipositing on January 1 to be still alive 
and laying eggs the following January along with the progeny of 
11 generations of her descendants. It is, therefore, small wonder 
that the melon fly, under such favorable conditions, swarms through- 
out the market gardens of Hawaii and leaves little unaffected that is 
not protected by man. 
CONTROL MEASURES. 
NATURAL CONTROL. 
No agencies at present are working in the Hawaiian Islands to 
bring about, even periodically, a very large natural reduction in the 
abundance of melon flies. The mortality among the immature stages, 
or among the adults, is not sufficiently high to be of practical value, 
although sometimes 90 per cent of the larvae may be found dead in 
certain decaying fruits. 
In climates colder than that of the Hawaiian coastal areas mor- 
tality due to cold temperatures will play a particularly active part 
in reducing the pest- While the cooler weather of the winter months 
does prolong the period of development throughout the coastal re- 
gions, the long life of the adult flies and the capacity of females for 
continued egg-laying make it difficult for market gardeners to benefit 
to any marked extent from the effects of cool weather if they allow 
their fruits to remain unprotected. The cooler weather in the more 
isolated gardens holds down the number of adults and limits their 
activity to a fewer hours during the day when it is warm enough for 
them to attack fruits, and in this way makes possible greater success 
in saving fruits by the use of various protective coverings than fol- 
lows the use of the same measures during the summer months. 
