METHODS OF COLLECTING 5 



One of the contributions made by Wasmann bears upon the present work. 

 After prolonged study, he suggested a sufficiently elastic classification of guests 

 of social insects. This grouping was essentially ecological, and in the modified 

 form used by Wheeler (1910, 1923) may be outlined as follows, with respect 

 to Pselaphidae. 



Synechthrans. Guests living within the nest but attacked and killed by 

 the hosts when possible; usually scavengers, or active predators of the host 

 workers, their brood or their food stores and other guests. Such forms are 

 especially numerous in examples among the Staphylinidae, but no bona fide 

 synechthran is known to me within the Pselaphidae. Synechthrans, by the very 

 nature of their role, are strong active species as a rule and are least specialized 

 for life within the nest biocoenose, of the guests. 



Synoeketes. Guests living within the society without being actively perse- 

 cuted by the host; usually indifferently tolerated. Such forms are slower mov- 

 ing as a rule and more specialized for the social group than are the synech- 

 thrans. Wheeler subdivided this second type into six categories: (1) Neutral 

 Synoeketes "insects which pay no attention to the ants or their brood, but 

 live on the refuse or nest materials and spend their time seeking these on the 

 walls of the galleries and chambers." (2) Mimetic Synoeketes in which the 

 species show, to the human perceptions at least, structural or ecological char- 

 acteristics which are quite similar to the hosts. (3) Loricate Synoeketes in 

 which the body is flattened, rounded, and tapered. Usually the species are 

 relatively inconspicuous. (4) Symphiloid Synoeketes in which the species be- 

 comes more intimately adjusted to the host, approaching the true guests. (5) 

 Myrmecocleptics, a category formed for the Lepismid, Atelura formicaria, 

 by Janet (1896). This insect is of the loricate body form, but steals up to 

 two regurgitating ants and partakes of the liquid food passing between them. 

 (6) Strigilators, a term proposed by Wheeler (1910) for a group of diverse 

 insects which "lick the surfaces of ants and seem to feed very largely, if not 

 exclusively, on the cutaneous secretions and the thin coating of saliva with 

 which the ants cover one another." 



The Pselaphidae number representatives in this second division of guests. 

 Tmesiphorus costalis may be said to be a facultative mimetic synoekete (Park, 

 1933), and Batrisodes globosus also falls in this type (Park, 1935b). Both 

 species can and do live in mold and under loose bark or stones on the floor, 

 but both are found with ants and are known to feed upon the host brood. 

 They are not persecuted by their hosts, nor are they cared for in any obvious 

 way. The species of Rybaxis, and possibly Ceophyllus and Cedius may also 

 be synoeketes in the strict sense of the word. 



Symphiles. These are true guests of the social insects, and are found 

 among the Staphylinidae, Paussidae and Clavigerinae. As has been stated by 

 Wheeler, these are the elite of the guests. All of the clavigerids are symphiles 

 and agree in having certain "symphilic characters and behaviorisms" as far 

 as known, e.g., (1) the peculiar, oily integument, usually yellowish to reddish 

 brown in color, strikingly similar to their hosts; (2) the well-developed, oily. 



