A total of 280 laboratory colonies of Reticulitermes urbis were raised for 3 years, in order to observe caste
differentiation and overall colony growth, and to investigate whether the initial composition (0, 2 or 4 nymphs;
0, 5, 10, 20 or 50 workers) affected colony survival, population growth and other colony dynamics. We also
wanted to determine the minimum number of individuals needed to establish a vital colony. As a result, every
colony beginning with less than 20 workers died within 60 weeks, while colonies beginning with at least 20
workers survived until the end of the tests, with varied survival rates dependent upon the initial size and the
time of formation (summer or autumn). The number of nymphs did not affect colony survival and colony
growth. Reproductives developed from nymphs within 2 weeks and later from workers. Many of the
reproductives derived from nymphs were killed by workers. The majority of the colonies contained two
reproductives 3 years after initiating the tests. In addition, a few individual workers were still alive at the end
of the 3-year tests. At the end of the tests, the proportion of soldiers ranged anywhere from 5.23 to 7.69% of
the total population. The number of viable \u201cjuveniles\u201d from each colony was relatively low throughout the
tests and the overall population growth was not sufficient enough to replace dead workers or increase the
colony size considerably. These results indicate that the potential to establish viable and sustainable colonies
for groups of R. urbis composed of 5\u201350 workers is very low
