Abstract
The developmental cycle, habits, host associations, and control of the chigger Neoschongastia americana (Hirst) was studied. Laboratory rearings of the chiggers were conducted at 70°, 80°, and 90° F in total darkness and at 90° F in an LD:14-10 hour photoperiod. No development occurred past the nymphal stage at 70° F, and no reproduction occurred in adults held in the LD:14-10 hour photoperiod. The developmental cycle was completed in 91 days at 90° F (dark) and in 157 days at 80° F (dark). The egg stage averaged 7.5, deutovum 7.1, nymphochrysalis 7.5, nymph 15.6, imagochrysalis 7.5, and preoviposition 35-84 days at 90° F. At 80° F, these same stages required 12.4, 11.8, 17.8, 21.2, 13.0, and 74-141 days respectively. The larvae fed upon quail at room temperature in the laboratory for an average of 7.4 days and were then active for several days before entering the nymphochrysalis stage. Some adults lived more than eight months and certain females produced several hundred eggs during their life span. The adult males deposited stalked spermatophores about 70 microns tall which served as the mode of insemination. Probably only one generation per year occurs over most of the range of N. americana, but two generations may be possible in some areas. Descriptions of the nymphal and adult stages are included. ...
Everett, Ronald Edmond (1971). The biology, alternate hosts, and control of the chigger, Neoschongastia americana (Hirst). Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -170388.