CHIGGERS — FARRELL 103 



directly on slides or were stored in small glass tubes in 85 percent 

 ethyl alcohol. 



Records were kept of hosts and chiggers by collections. A col- 

 lection of hosts consisted of all host specimens of one species 

 taken in one locality on one date. A collection of chiggers con- 

 sisted initially of all chiggers taken from one collection of hosts. 

 Later, the separate species of chiggers were identified. The num- 

 ber of individual hosts infested was determined for each collection 

 by direct examination or by recovering chiggers over water ; but 

 chiggers were identified from collections of hosts, not from the 

 separate host specimens. In Duke Forest a compartment was 

 considered a locality. If a single trap line extended through two 

 compartments, it was considered to lie in one locality unless a 

 stream separated the compartments. In the latter case the line 

 was considered to lie in two localities. Outside Duke Forest, 

 streams or main highways were considered to be boundaries 

 separating the localities. 



Unattached chiggers were collected through Berlese funnels 

 from soil and other materials from various ecological niches. 

 A battery of four funnels, each 48 cm. wide by 58 cm. high, was 

 used. A rack supporting four electric lamps in large reflectors 

 was constructed to supply top heat for drying the materials 

 placed on the funnels. Small beakers and bottoms of weighing 

 bottles were half filled with water and placed under the funnels 

 to receive the organisms. The glassware rested on squares of 

 insulation board swabbed with benzol benzoate. Unattached 

 chiggers obtained through Berlese funnels were handled in the 

 same manner as chiggers from hosts. 



Chiggers contributed by collectors working on other projects 

 usually were shipped alive to the laboratory in the special char- 

 coal-lined vials. The most extensive of these collections were 

 those of the Pennsylvania Mammal Survey, which continued 

 throughout the year. However, these collectors generally made 

 shipments only when infestations on mammalian hosts were 

 highest. 



Living chiggers were used extensively in efforts to establish 

 cultures. Eighty- three cultures of Euschongastia were started. 

 A variety of containers were tried. Standard pint canning jars 

 and tall 12-ounce bottles were tried with bottoms removed 

 and the openings filled with a mixture of plaster of Paris 90 parts 

 by weight and Merck's animal charcoal 10 parts by weight. In 

 use these containers were placed in small finger bowls. Wide- 



