1914] Melon Fly, Dacus cucurbitae. 187 
Van Dine (11, pp. 32-34) gives the following contribution 
on the life history of the melon fly: The life history covers a 
period of about three weeks. The number of eggs which the 
female deposits varies from 5 or 6 to as many as 15. After 
hatching from the egg, the larve burrow into the tissue of the 
melon and feed on the interior. When fully developed the 
larve leave the infested melon or vine and enter the soil directly 
beneath, where at a distance of an inch or so from the surface 
they pupate. 
Marsh (9, p. 156) writes, “In the insectary an effort was 
made to work out the life history of this fly, but little progress 
was made owing to the fact that the cages in which the speci- 
mens were confined were too small.”’ 
11. Methods of inducing oviposition—Various methods 
were adopted to induce melon flies to lay their eggs in different 
food plants placed in a pumpkin patch swarming with the pest. 
One method followed was to cut a non-infested, ripe pumpkin 
in half and the trypetids which were probably attracted by 
the odor of the pulp, would visit the cut surfaces and deposit 
their eggs. Even the removal of a small piece of the rind from 
a pumpkin or squash would be sufficient to attract and induce 
the insects to oviposit. Another method used was to make a 
semicircular cut through the peel and pulp near the surface 
of cucumbers, egg plants and tomatoes and the loose flap was 
then pinned back like a lid. After the females had deposited 
their eggs in the pulp, the lid-like peel was pinned into its normal 
position again, thus covering the eggs. 
In one experiment about a square inch of the rind of a 
pumpkin was removed and in a short time melon flies began to 
visit the injured vegetable. The flies wandered about upon 
the rind until they found the exposed pulp, when they began 
to feed upon the exuding juices. At times as many as twenty- 
five specimens were clustered together in this small area. So 
closely crowded were the insects that their wings, which are 
usually held at almost right angles to the long axis of the body, 
overlapped. More and more individuals were attracted to the 
cut area until the newcomers were actually forced to walk 
over the bodies of the earlier arrivals, some of which were now 
laying eggs without apparently being disturbed, for the ovi- 
positor was not withdrawn. 
