We have analysed the distribution of queens under stones at the core and at the periphery of a supercolony of
Lasius neglectus that occupies 14 ha at Seva (NE Spain). Queens were not found alone,
but rather within worker groups. Density at the center (mean ± s.d.: 1.38 ± 2.87 queens/stone; n = 100 stones;
range 0–14) was not different from density at the periphery (1.18 ± 2.38; range 0–12). The estimate of
the number of queens found under stones for the whole colony is about 35500. Egg-laying rates for queens from these two
zones were obtained in the laboratory, at three different temperatures, and there were no differences detected. The
presence of brood stages, from eggs to cocoons, was also similar in both zones. The homogeneous distribution of colony
components may indicate that the area occupied by
L. neglectus has already reached
saturation. With a different technique – soil core extraction – we could estimate the density of workers in
the soil: 800 workers per m
2. Soil cores had 6.28 ± 20.0 workers/core
(range: 0–173), giving a rough estimate of 1.12 × 10
8 workers in the soil, for the
entire colony. Though few, some queens were also recovered from soil cores. Queen numbers for the supercolony, based on
queens found in the soil, reaches the astounding level of 360000. Numbers are consistent with previous predictions.
Egg-laying rate - Lasius neglectus - polygyny - queen distribution - worker density
Received 10 September 2003; revised 1 December 2003; accepted 9 December 2003.