INTRODUCTION 



COLLECTION AND PRESERVATION 



Fleas may be collected directly from the mammalian and 

 avian hosts or their nests, runways, or burrows. In many in- 

 stances certain species have been taken in sweepings and debris 

 on the ground. Nests should be collected very soon after the 

 young leave and each placed in a paper bag, or better under a 

 bell jar where they can be watered occasionally to prevent 

 drying out. If watered occasionally the immature stages con- 

 tinue to develop making it possible to obtain numerous speci- 

 mens in all stages of development. 



The hosts, themselves, should be captured by traps which 

 take them alive, for fleas will soon leave the dead animal. After 

 capture, the animal is anesthetized or killed by ether or chloro- 

 form and its ectoparasites dislodged by searching through the 

 pelage with forceps or by combing with a fine-toothed comb. 

 Taking the animal alive allows no opportunity for escape of the 

 fleas, and thus best results are obtained. Under usual condi- 

 tions, however, it is much more convenient to run traps which 

 kill the animal. While a large percentage of the fleas are no 

 doubt thus lost, a sufficiently large number remain to make this 

 type of trapping worthwhile. Common mouse traps or guillo- 

 tine traps may be used successfully to procure small animals 

 such as wood mice and shrews. When abundant, rats and squir- 

 rels may be shot or even clubbed. 



If possible, the dead animal should be placed immediately in 

 a paper bag and carried to the laboratory where it can be ex- 

 amined under a binocular microscope. By this method not 

 only fleas, but also lice, mites, and ticks can be collected. If an 

 animal is heavily infested, it is helpful to stupefy its fleas with 

 an insect powder, collecting them from white paper after comb- 

 ing the fur. Public health workers have found it easy to col- 

 lect fleas from rats by placing the recently killed animal on a 

 grating over water; the fleas in leaving the dead host jump into 

 the water from which they may be collected readily. 



Fleas are prepared for study by mounting in Canada balsam 

 on glass slides. To accomplish this, various techniques have 

 been used with good results. Soft parts and intestinal contents 

 must be cleared before the important genitalia can be studied. 



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