CHIGGERS — FARRELL 101 



scutum, the Standard Data. Directions for photomicrography of 

 the scutum and the whole mite were given by Gill and Parrish 

 (1945). Wharton (1947a) outlined the development of chigger 

 description and presented his method of recording morpho- 

 logical units in a series of drawings; and in 1948 he called 

 attention to the value of the specialized setae of the legs in 

 grouping and identifying species of chiggers. Wharton, Jenkins, 

 et al. (1951) contributed a list of characters useful in descriptions 

 of both larvae and adults, with a glossary of terms. Through 

 the years most workers have used drawings to supplement their 

 written descriptions. 



Materials and methods 



The chiggers collected in the Duke Forest area for this study 

 were taken mostly from infested small mammal hosts which v/ere 

 trapped during a program extending from September 1947 to 

 December 1949. When transportation facilities permitted, traps 

 were set on Saturday afternoon of each week and were picked 

 up early on Sunday morning. During Christmas and spring 

 vacations, trapping usually was continuous and traps were 

 visited each morning. Areas to be trapped were determined by 

 reference to the Forest Cover Maps published by the Duke 

 University School of Forestry on July 1, 1944. The system of 

 compartment identification used on these maps has been followed 

 in this paper. 



Museum special snap traps, supplemented by one or two ordi- 

 nary rat traps, made up the standard trap line. The number of 

 traps set varied, but it was usually about 35. The bait generally 

 used was oatmeal moistened with saliva and pressed on the trig- 

 ger. Two types of box traps were used infrequently — a single 

 trap with a drop door, baited with apple or carrot, for rabbits, 

 and several box traps with inward swinging hardware cloth 

 doors, baited with oatmeal or carrot, for mice. On two occasions 

 lines of steel traps were run continuously to collect fur bearers. 

 One line was kept out for eight days in February 1949. A second 

 line was operated for 16 days in November and December 1949. 

 A shotgun was used to collect squirrels, rabbits, and bats; small 

 mammal highway casualties were picked up; and gifts of verte- 

 brates were accepted from other workers in the area. 



No organized collecting was done for vertebrates other than 

 mammals, but they were collected occasionally. Reptiles, par- 

 ticularly, were collected whenever opportunity offered. 



