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Psyche 
[Vol. 95 
tube-nests as described by Buschinger and Heinze (in press). In the 
lab, the colonies were kept in formicaries according to Buschinger 
(1974), and fed three times a week with diluted honey and insect 
pieces ( Tenebrio molitor pupae, cockroaches). Artificial daily and 
annual temperature cycles were applied in analogy to that which 
had proved to be effective in rearing other leptothoracines from 
high elevations in the Alps. 
Thus, “summer” conditions with 10h/17°C and 14h/28°C daily 
(dim light during the warm hours) were provided from the arrival in 
the lab on 28 May 1987 for 6 weeks, until most sexuals had left the 
nests for mating, and pupation had ceased. “Fall” conditions were 
simulated with 1 2h / 15°C and 12h/25°C for another 6 weeks, fol- 
lowed by 1 2h / 10° C and 1 2h / 20° C for 3 weeks until the larger larvae 
had somewhat shrivelled. The colonies then were placed in hiberna- 
tion conditions at a constant 10° C for five months. After 2 weeks at 
10/20°C and 6 weeks at 15/25°C the first new prepupae appeared in 
the nests, and in 17/28°C a week later sexual pupae were observed. 
The whole “annual cycle” thus was shortened to about 10 months. 
No different temperature regimes were tested, but might as well be 
suitable. 
Sexual behavior was observed either spontaneously in the formi- 
caries, or sexuals who had left the nest chambers and were crawling 
and fluttering around were placed into a transparent flight-cage (15 
X 20 X 30 cm) exposed to natural or artificial light. Females were 
dissected for control of insemination as was described by Buschin- 
ger and Alloway (1978). For colony foundation experiments single 
newly inseminated females, or dealate ones found in the formicaries, 
were placed into a formicary containing a queenright or queenless 
host-species colony. 
Results 
Sexual behavior: 
As in most leptothoracine ants the young sexuals of C. brunneus, 
when ready to mate, leave the nest and, in our formicaries, crawl or 
flutter around. When transferred into the flight-cage, they move 
towards the light and assemble in a loose “swarm” like sexuals of 
other Chalepoxenus species. The C.b. sexuals, however, are 
generally quite sluggish with respect to flying. 
