1912] Mediterranean Fruit Flies 401 
The conditions existing in South Africa are entirely different 
from those in Honolulu and the outskirts of this city where our 
experiments on the flight of the marked Mediterranean fruit 
‘flies were performed. There are only a very few small orchards 
in and around the city of Honolulu but in practically every 
dooryard surrounding a residence a great variety of fruits are 
‘grown such as various kinds of citrus fruits, coffee, figs, garden 
varieties and wild guavas, mangoes, papaias, peach, plum, rose 
apple, tropical almond (umbrella tree or ‘“‘kamani’’ nuts) sour 
‘sop, star apple, etc., from which we have bred the pest. These 
‘cultivated fruits ripen at different times of the year and offer 
the insect a regular succession of fruits in which to breed. In 
the uncultivated as well as in the mountainous districts of 
Honolulu the prickly pear which is also attacked by the fly is 
scattered over large areas. Different species of wild guaves 
which are hosts of the pest cover thousands and thousands of 
acres on the slopes of the mountains, in the gulches, in unculti- 
vated portions of the valleys and plains, along the banks of 
‘streams and along some of the roads and paths leading from the 
city. These different species of wild guavas bear fruit practic- 
ally the year around. Other wild fruits which the insect 
attacks are the mountain apples and the wild coffee berries. 
‘The climatic conditions in the Hawaiian Islands are also very 
favorable for the development of this trypetid, a generation of 
flies appearing about every four or five weeks throughout the 
year. In the city of Honolulu there is thus, a regular succes- 
sion of cultivated fruit for the fruit fly to breed in, and in the 
outskirts of the city and in the mountainous districts wild fruits 
are available for the pest during the entire year. 
In order to determine positively the powers of flight of the 
Mediterranean fruit fly, two thousand male specimens, which 
were bred in the laboratory from infested fruits, were handled 
and marked so that they would be injured as little as possible 
by employing the following methods: Hundreds of fruit flies 
were liberated under a small cheese-cloth tent which was fastened 
at its base to the three sides of a table and at its apex to the 
ceiling by a string. The head and shoulders were thrust under 
the tent at the open side and each specimen was captured in a 
small vial. The fly within the vial was seized by one wing 
with a pair of forceps, around the end of one prong a small 
elastic band had been wound. The fruit fly held by one wing, 
