1983] 
Rissing — Pogonomyrmex colei 
327 
Table 2. Continued. 
Inquiline species 
Host species 
Fate of host 
queen(s) 
Reference 
Mononiorium 
talbotae 
Mononiorium 
minimum 
survives 
Talbot 1979 
Struniigenys 
xenos 
Struniigenys 
perplexa 
survive 
Brown 1955, Taylor 1967 
FORMICINAE 
Plagioiepsis Plagiolepsis 
xene pygmaea 
survive 
Le Masne 1956; 
Passera 1964, 1966, 1972 
Aporotnyrmex 
ampeloni 
Plagiolepis 
vindohonensis 
survives 
Faber 1969+ 
♦Presence of host queen(s) determined by presence of host reproductives 
+Cited in Wilson (1971) 
(Buschinger 1981, Buschinger and Winter 1982) may explain this 
behavior which is rather unusual among most other inquilines 
(Table 2). Only the extreme inquiline Teleutomyrmex schneideh is 
known to enter established host nests without having to eliminate 
host queens; these inquilines may produce a substance highly 
attractive to host workers (reviewed in Wilson 1971). 
Comparison with P. anergismus and other workerless inquilines. P. 
colei may represent an intermediate form between its host P. 
rugosus and the closely related workerless inquiline P. anergismus 
(for a complete discussion of morphological differences see Snelling 
1981). Discovery of P. colei adds the genus Pogonomyrmex to a 
growing list of ant genera with more than one workerless inquiline 
species (Table 2). Such “concentration” of inquilines into a few 
genera may occur either due to non-random search by myrmeco- 
logists {P. colei was discovered during an intentional search for 
Pogonomyrmex inquilines) or because certain genera are more 
likely to give rise to inquilines. The basic biology of the inquiline- 
rich genera, however, is quite variable suggesting several evolution- 
ary routes may lead to workerless inquilinism. The genus Lepto- 
thorax, for example, has small, ephemeral colonies subject to slave 
raids from numerous species and has given rise to several closely 
