198 Annals Entomological Society of America  [Vol. VII, 
IX. METHODS OF CONTROL. 
27. Experiments in destroying infested vegetables.—Van Dine 
(11, p. 35) formerly stationed at the Hawaiian Agricultural 
Experiment Station, recommends that all melons and vines 
infested with melon fly larve should be collected at intervals of 
five or six days and covered with earth to a depth of several 
inches. 
A number of experiments were performed to determine the 
distance that melon flies, after issuing from the puparia, were 
able to burrow through sand and soil. In the first experiment 
several, hundred puparia were placed on two inches of dry, 
sterlized sand at the bottom of a cylindrical, museum jar 
(24x111% inches) and this jar was then filled with more of the 
same kind of sand. A similar vessel, half filled with dry sand, 
was then inverted over the top of the above mentioned jar. 
This was done by placing a heavy, glass plate over the mouth 
of the jar to be turned upside down, inverting the same above 
the other vessel and then pulling the glass plate out from be- 
tween the two jars. A similar experiment was conducted with 
wet sand which had been previously sterlized. The puparia in 
both experiments were arranged in a circle close to the wall of 
the jars so that when the fruit flies emerged and burrowed 
through the sand their paths might be seen. When the trypetids 
emerged, many would bore up to the region where the jars came 
in contact with one another and then escape through the small 
spaces between the jars. These small spaces were due to par- 
ticles of sand which rested on the rims of the jars. One could 
scarcely believe that these large flies were able to flatten their 
bodies to such an extent as to squeeze through such small 
spaces as existed between the jars. 
It was evident that some of the melon flies were not able to 
burrow as far as others, for many died at the upper end of the 
channels before obtaining their liberty (plate XX XI, fig. 45). 
Flies would frequently bore into an excavation made by other 
specimens and if the union of the channels would form a more 
or less circular path, some of the individuals would continue 
to burrow slowly round and round and finally die in this endless 
passage. Usually, however, most of the trypetids showed 
a definite orientation and bored directly upward. This nega- 
