Collecting and Handling 



45 



opening of the vial by applying pressure to the center of the screen. When the cone 

 was thus shaped, a small hole was cut in its apex. The cone was then placed in the 

 vial again and the corners of the screen trimmed off. The cone can then be forced 

 a little way into the vial, remaining in place by the spring-action of the bent wire 

 against the side of the glass. Care should be taken not to make the cone so small 

 that it will drop out. 



Insects that seek the light on emergence from the pupal stage are 

 easily collected in a very simple trap. 

 They are placed in a dark box before 

 emergence. A hole is bored in one 

 side of the box, and the open end of 

 a glass vial is fitted into the hole. 

 Light entering only through this hole 

 attracts the insects to enter the vial, 

 from whence they are easily removed. 

 This is adequate for most minute 

 parasites, but for larger and livelier 

 insects, such as screw-worm flies,* a 

 fruit jar with a cone-shaped baffle 

 guarding against return of the flies to 

 the box, may replace the vial. 



For picking up minute beetles by 

 suction Frank J. Psota of Chicago 

 devised an efficient aspirator (Fig. 

 40) which he has described** as 

 follows: 



Fig. 40.- — A suction-pump collector. 

 After Psota. Two longitudinal sec- 

 tions through suction-pump collector 

 and (to the right) a cross-section 

 through the same above the middle, 

 looking upward. 



"The apparatus is shown in the accom- 

 panying figures: A, is a cork with center 

 hole; B, a glass tube 4 inches long, 1% inch 

 in diameter, and z /i inch thick ; C : cork of 

 type similar to A; D, glass tubing bent 

 in S-shape; this curve is very important 

 because it destroys a straight path for in- 

 sects and dust; E, glass tubing % inch in 

 diameter with enlarged edges on both sides of the cork; F, rubber tubing which is 

 of the desired length (usually 20 to 30 inches), with mouthpiece on one end, the other 

 is slipped over the glass near the cork; G, short piece of rubber tubing which prevents 



♦This is the device used successfully by Mr. D. C. Parmann at the Laboratory of the 

 U. S. Bureau of Entomology at Uvalde, Texas. A rim-capped fruit jar is used, with the 

 center of the cap left out. The rim is fixed inside a large hole bored in the side of the 

 rearing box, and the jar is screwed into it. A cone of wire cloth with an opening at its 

 apex large enough to admit the flies, is so shaped that its base is held firmly between the 

 jar and the screw cap when these are put together, the apex projecting into the jar. 

 Thus the escape of the flies is prevented, until the baffle is removed. 



**Ent. News 27:23, 1916. 



