385 
THE GUESTS OF YORKSHIRE ANTS. 
T. STAINFORTH, B.A., B.Sc. 
OF the various modi vivendi adopted by our indigenous insect 
fauna, none is more interesting than that of inhabiting ants’ 
nests as welcome or unwelcome guests. Between seventy 
and eighty species of British Coleoptera, besides other classes 
of animals, have been recorded from ants’ nests, and, while 
in many instances the relationship is purely accidental, in 
the greater number of cases there is an actual association 
between the beetle and the ant. This association may be one 
of friendliness, toleration, or hostility; and though these 
relationships merge into one another, it is possible to classify 
our myrmecophilous fauna under three main heads: (1) true 
guests, (2) indifferently tolerated tenants, and (3) actively 
pursued tenants. These are respectively the symphiles, 
synoeketes, and synechthrans of Wasmann, who also particu- 
larises parasites (ento- and ecto-), and trophobionts or food- 
producing animals of the ants.* 
TruE Guests.—In our British beetle fauna six species 
occur under such conditions that they may be considered as 
true and welcomed guests, or symphiles, in the nests of various 
ant species, viz.:—Lomechusa strumosa F., Atemeles emar- 
ginatus Pk., A. paradoxus Gr., Claviger testaceus Preys., C. 
longicornis Mill., Amphotis marginata F. 
Of these, only one species, Atemeles emarginatus, has hitherto 
been recorded for Yorkshire, and to this may now be added 
Claviger testaceus (foveolatus Miull.). This latter species, per- 
haps the most interesting of our myrmecophilous insects, [I 
found at Robin Hood’s Bay in September, 1911, when I secured 
two examples on the underside of a half-embedded boulder 
forming the roof to a nest of a colony of the Yellow Ant, 
Donisthorpea (Lasius) flava. 
The Clavigers are in structure remarkable among beetles. 
Their mite-lke form, small size (2 mm.), thick antennae, and 
abdomen furnished with a peculiar depression and tufts of 
vellow hairs, render them easily recognisable. C. testaceus 
is rarely found elsewhere than within the nest of a species of 
Donisthorpea usually D. flava, but occasionally D. aliena or 
D. nigra. Our two British Clavigers are probably the most 
specialised of our indigenous coleoptera for a myrmecophilous 
life. They are blind, fed as a rule by their hosts (but Donis- 
thorpe and Prof. Hetschko have proved experimentally that 
they are capable of feeding themselves on the larve of ants 
* See ‘The Ants and their Guests,’ P. E. Wasmann, Smithsonian 
Rep., 1912, pp. 455-474; and ‘Ants, their Structure, Development and 
Behavior,’ W. M. Wheeler, Columbia Univ. Biol. Ser. IX., 1910, p. 380. 
1915 Dec. 1. 
