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Psyche 
[Vol. 95 
in one colony we found two queens, and five colonies were queen- 
less. The latter were orphaned already in the field, or we had lost the 
queens during collecting. None of the 12 colonies contained a host- 
species queen, but most had a C. brunneus brood, the small pupae 
being easily identifiable. A variable number of about 15 to 80 L. 
marocanus workers was present. 
These field records suggest that the host species queens might be 
eliminated by the C. brunneus queens, as in the related dulotic 
Chalepoxenus species. With a total of 24 dealate C.b. females, col- 
ony foundation experiments were set up, using 6 queenright and 4 
queenless L. marocanus colonies (Tab. I). Since many C.b. females 
died soon or were killed by the host-colony workers, up to four C.b. 
females were introduced subsequently into one nest. In a few instan- 
ces (col. no. 5 and 8) where the C.b. females died during or after 
their first hibernation, newly reared females were introduced in the 
following “summer”. Out of 20 females which died during the exper- 
iments, nine could be dissected; 6 of them were inseminated and 3 
were not. Thus, lack of insemination cannot explain the failure of so 
many females. 
In the four queenless host-colonies a total of 9 C.b. females were 
introduced. Only one (col. no. 1) was successful in that male and 
female offspring were reared in the year after the colony foundation. 
In another colony (no. 4) only one C.b. male was produced. 
Fifteen C.b. females were placed into the six queenright host 
colonies. In two colonies both male and female offspring were 
reared; in two others only one and seven males, respectively, were 
reared. 
Most interesting is the behavior of the C.b. females toward the 
host colony queens. Unfortunately, the results are somewhat 
ambiguous. Clearly, in colonies no. 6 and 9, the C.b. females killed 
the host colony queens. In col. 6 this happened 27 days after the C.b. 
female had been introduced into the nest. The L.m. queen was 
presumably stung; she was paralyzed, lying on her side or back, and 
a week later she was dead and carried out of the nest. Nevertheless, 
the C.b. female in this nest did not reproduce. In col. 9 a total of 
three C.b. females were killed first by the host workers (two were 
not inseminated, the third one could not be dissected), until the 
fourth C.b. female finally succeeded in paralyzing the L.m. queen, 9 
days after the introduction. During this time the C.b. female had 
been staying within the nest, among the workers and brood; she had 
