CHIGGERS — FARRELL 97 



T. alfreddugesi from chiggers of four infested Carolina terrapins. 

 The terrapins were placed in containers with sand on the bottoms. 

 The chiggers detached easily. One nymph was placed in a small 

 cell with cockroach feces. It died after 31 days without trans- 

 forming. Ewing (1926b) obtained many nymphs and a single 

 adult of Hannemania hylae (Ewing, 1925), subfamily Leeuwen- 

 hoekiinae, from engorged larvae in soil on which their tree frog 

 hosts had been kept. He described the nymph and adult and 

 figured all three active stages. Andre (1930) reported rearing a 

 njanph of T. autumnalis, Keay (1937) reared a "considerable 

 number" of nymphs from fully engorged T. autumnalis larvae 

 placed in sterilized soil in an atmosphere saturated with moisture. 

 Nymphs were obtained by Gunther (1939b) from engorged 

 Trombicula sp. larvae placed in jars with moist, sterile soil. In 

 1944 Ewing (1944b) reported having reared nymphs of T. alfred- 

 dugesi from larvae engorged on toads. At this time he summarized 

 the life cycle of this species as it was known — the egg removed 

 from the abdomen of an adult female, the larva, the nymph, and 

 the adult. 



The first successful culturing of chiggers in which reproduction 

 occurred and subcultures were established was reported by Melvin 

 (1946) and Michener (1946), working with T. batatas (Linnaeus, 

 1758). They worked in the same laboratory and their methods 

 were similar. Both used baby chicks as hosts for the larvae. 

 Engorged larvae were placed in bottles or jars containing soil 

 mixed with chicken manure in which the mites completed their 

 development. No food was offered in addition to the chicken 

 manure-soil mixture. Michener described and figured the seven 

 stages of the life cycle. 



None of these workers determined the food requirements of the 

 free-living stages. Then Wharton (1946) and Wharton and 

 Carver (1946), working with Euschongastia indica, discovered 

 that insect eggs were suitable food for the nymphs and adults. The 

 feeding process was observed with a dissecting microscope. 

 Drosophila, Culex, and Aedes eggs and the eggs of other species 

 were used. Adults were observed, also, to feed on their own eggs 

 and on ant larvae. What appeared to be an unsuccessful attempt 

 at cannibalism by one nymph upon another was seen once. 

 Nymphs and adults were obtained from engorged larvae, and 

 these reared adults produced larvae. Wharton (1946) gave de- 

 scriptions of all stages, figures of egg, deutovum, larva, nympho- 

 chrysalis, and nymph, and photographs of all stages except the 

 egg. After the discovery of insect eggs as food for the free- 



