BURROWING HABITS OF 
NORTH AMERICAN SOLPUGIDA (ARACHNIDA) 1 2 
By Martin H. Muma 
Citrus Experiment Station 
Lake Alfred, Florida 
Introduction 
North American solpugids, with the possible exception of a few 
small species of Hemerotrecha Banks and Therobates Muma, are 
nocturnal. During the daylight hours, the animals rest in specially 
constructed burrows that vary in depth from i to 23 cm. Burrows 
are also constructed for food digestion, ecdysis, hibernation, and egg 
deposition. An individual solpugid may, during its lifetime, dig 40 
or more burrows. 
Despite the extensive digging operations seemingly necessary for 
their survival, solpugids curiously lack special burrowing structures 
(Hingston, 1925). Excepting species of Hexisopodidae, this state- 
ment seems to be true for all solpugids (Lawrence, 1963). Burrow- 
ing, although conducted with extreme vigor and activity, seems to be 
accomplished inefficiently and laboriously. 
The general facies of solpugid burrowing were presented by Hut- 
ton (1843), Turner (1916), Hingston (1925), and Fichter (1940). 
Although these recorded observations indicated a basic similarity in 
solpugid burrowing activities, differences suggested possible variations 
in habit between families, genera, and species. 
This report presents a systematic comparison of the burrowing 
habits of North American solpugids. 
A cknowledgrnents 
Special acknowledgments are due the personnel of the American 
Museum of Natural History’s Southwestern Research Station at 
Portal, Arizona, for the provision of living and research facilities 
in the collection area. Mr. Vincent A. Roth, Director, and student 
assistants also collected specimens. 
Mrs. Thelma G. Kanavel, technician, and Michael S. Ball, stu- 
dent, made or assisted with many of the observations reported here. 
Partial report on studies supported by National Science Foundation 
Grant GBS-496. 
2 Florida Agricultural Experiment Stations Journal Series No. 2482. 
Manuscript received by the editor September 27, 1966. 
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