BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS 211 



Class ARACHNIDA 



In this class, representatives of at least four orders have utilized 

 cockroaches as food : the whip scorpions, scorpions, spiders, and 

 mites. Apparently none of these feed exclusively on cockroaches, but 

 the Philippine forest scorpion Heterometrus {=Palamnaeus) longe- 

 manits seems to prefer blattids to other insects (Schultze, 1927). 



Order PEDIPALPIDA 

 Family THELYPHONIDAE 

 Mastigoproctus giganteus (Lucas) 



Synonymy. — Thelyphonus giganteus Lucas [Dr. R. E. Crabill, per- 

 sonal communication, 1958]. 



Experimental prey. — Cockroaches, U.S.A. (Marx, 1892, 1894) : 

 Immature whip scorpion captured and fed on one or two cockroaches 

 a week. It lived on this diet for about two years. 



Mastigoproctus sp. 



Common name. — Whip scorpion. 



Experimental prey. — Blattella germanica, U.S.A., Florida [Dr. 

 B. J. Kaston, personal communication, 1953]. 



Order SCORPIONIDA 



Pocock (1893) noticed that a scorpion whose pectines had come in 

 contact with a cockroach immediately turned back and ate the insect. 

 He concluded that the scorpion detected the cockroach by means of the 

 pectines. However, Cloudsley-Thompson (1955) has demonstrated 

 that the main function of the pectines is probably the detection of 

 ground vibrations. He accounted for Pocock's observation by the 

 presence of sensory spines (presumably tactile) which project from 

 beneath the pectines. In a house in Arizona, Lyon (1951) observed 

 over 60 scorpions living in a kitchen cabinet that enclosed a sink. They 

 were apparently thriving on a heavy infestation of cockroaches. 

 Stahnke (1953) stated that he used Periplaneta americana as the prin- 

 cipal food for scorpions at the Poisonous Animals Research Labora- 

 tory of Arizona State College. Qoudsley-Thompson (1955a) cited 

 cockroaches as one of the arthropods that scorpions feed upon. 



Family BUTHIDAE 



Buthus australis (Linnaeus) 



Synonymy. — Androctonus australis [Crabill, personal communica- 

 tion, 1957], 



