188 Annals Entomological Society of America  [Vol. VII, 
12. Tactile bristles of the ovipositor.—The melon fly often 
seeks a suitable place wherein to oviposit by walking about on 
the cucurbit with the tactile bristles at the end of the ovipositor 
(Text fig. 4) in contact with the rind. These tactile bristles 
probably assist in locating a hole in the rind, or possibly discrim- 
inate between hard and soft surfaces. One specimen was 
observed with its ovipositor inserted within a pin hole which 
was made in a pumpkin and another female fly in orienting 
itself over this wound, would take a step or two backwards, 
grope around with the tactile bristles and finally push the 
ovipositor into the same hole. When a piece of the rind has 
been removed the flies apparently seek a soft area in the pulp 
with the tactile bristles of the ovipositor. The fruit flies will 
readily locate and oviposit in a slit which has been cut in the 
pulp. 
Text Fig. 4. Distal end of the ovipositor of Dacus cucurbite showing 
the tactile bristles. 
13. Process of oviposition—The process of oviposition can 
readily be observed in the field with a hand lens. When once 
the fruit fly has found a suitable place, the abdomen is bent at 
right angles to the long axis of the body and then the distal, 
needle-like part of the ovipositor moves up and down in the 
proximal, tube-like portion. As the ovipositor is forced into the 
food plant, the female, in endeavoring to get a firmer foot-hold, 
will let go with the tarsi and claws of the middle and hind legs . 
and grasp anew hold. The tube-like, proximal portion is thrust 
deeper and deeper until it disappears entirely and the eggs are 
then deposited. If, however, this tube has not been pushed 
entirely into the host plant, the eggs can actually be seen gliding 
through the ovipositor at the rate of one in about every fifteen 
or thirty seconds. Two specimens were timed during oviposi- 
