Table 2. Comparison of the genetic diversity within historical and recent populations of Bombus species.
| Species | Location | Historical time period (1913–1915) |
Recent time period (2013–2015) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | HE | SE | AR* | SE | N | HE | SE | AR* | SE | |||
| Restricted species | B. soroeensis | Torgny | 11 | 0.479 | 0.079 | 3.530 | 0.514 | 9 | 0.434 | 0.095 | 3.810 | 0.680 |
| B. humilis | Trivières | 13 | 0.358 | 0.079 | 3.220 | 0.527 | — | — | — | — | ||
| B. humilis | Torgny | 6 | 0.313 | 0.077 | 2.310 | 0.339 | 8 | 0.349 | 0.080 | 3.250 | 0.556 | |
| B. ruderarius | Moorsel | 10 | 0.333 | 0.085 | 2.750 | 0.504 | — | — | — | — | ||
| B. ruderarius | Nieuwpoort | — | — | — | — | 6 | 0.307 | 0.095 | 2.560 | 0.500 | ||
| B. ruderarius | Trivières | 15 | 0.354 | 0.092 | 3.400 | 0.658 | — | — | — | — | ||
| B. ruderarius | Torgny | 11 | 0.440 | 0.075 | 3.490 | 0.501 | 11 | 0.318 | 0.101 | 3.100 | 0.691 | |
| B. sylvarum | Moorsel | 7 | 0.316 | 0.089 | 2.440 | 0.484 | — | — | — | — | ||
| B. sylvarum | Trivières | 14 | 0.366 | 0.078 | 3.130 | 0.566 | — | — | — | — | ||
| B. sylvarum | Torgny | 18 | 0.509 | 0.074 | 3.870 | 0.498 | 15 | 0.345 | 0.089 | 3.270 | 0.720 | |
| Mean | 11.7 | 0.385 | 0.068 | 3.127 | 0.496 | 9.8 | 0.351 | 0.045 | 3.198 | 0.400 | ||
| Widespread species | B. pascuorum | Francorchamps | 17 | 0.458 | 0.093 | 4.120 | 0.673 | 26 | 0.478 | 0.085 | 4.340 | 0.727 |
| B. pascuorum | Moorsel | 21 | 0.493 | 0.083 | 4.410 | 0.639 | 21 | 0.459 | 0.086 | 4.170 | 0.738 | |
| B. pascuorum | Nieuwpoort | — | — | — | — | 19 | 0.454 | 0.090 | 4.420 | 0.833 | ||
| B. pascuorum | Trivières | 17 | 0.491 | 0.087 | 4.530 | 0.684 | 23 | 0.442 | 0.083 | 4.000 | 0.690 | |
| B. pascuorum | Torgny | 12 | 0.420 | 0.072 | 3.430 | 0.478 | 20 | 0.409 | 0.087 | 3.820 | 0.686 | |
| B. hortorum | Francorchamps | 18 | 0.596 | 0.087 | 6.320 | 0.952 | 25 | 0.584 | 0.092 | 6.080 | 0.981 | |
| B. hortorum | Moorsel | 24 | 0.557 | 0.094 | 5.800 | 0.911 | 20 | 0.580 | 0.095 | 5.950 | 0.929 | |
| B. hortorum | Nieuwpoort | 25 | 0.576 | 0.082 | 5.720 | 0.849 | — | — | — | — | ||
| B. hortorum | Trivières | 21 | 0.568 | 0.088 | 5.460 | 0.883 | 17 | 0.572 | 0.084 | 5.720 | 0.845 | |
| B. hortorum | Torgny | — | — | — | — | 23 | 0.563 | 0.089 | 5.710 | 0.907 | ||
| B. pratorum | Francorchamps | 18 | 0.554 | 0.081 | 9.040 | 0.686 | 22 | 0.557 | 0.078 | 5.070 | 0.751 | |
| B. pratorum | Moorsel | 12 | 0.606 | 0.061 | 4.380 | 0.568 | 19 | 0.630 | 0.071 | 5.560 | 0.764 | |
| B. pratorum | Trivières | 8 | 0.601 | 0.076 | 8.130 | 0.539 | 21 | 0.626 | 0.076 | 5.500 | 0.726 | |
| B. pratorum | Torgny | — | — | — | — | 20 | 0.639 | 0.075 | 5.480 | 0.652 | ||
| B. lapidarius | Francorchamps | 16 | 0.728 | 0.040 | 5.600 | 0.413 | 23 | 0.722 | 0.056 | 6.250 | 0.546 | |
| B. lapidarius | Moorsel | 14 | 0.690 | 0.040 | 5.350 | 0.506 | 20 | 0.728 | 0.054 | 6.310 | 0.519 | |
| B. lapidarius | Nieuwpoort | 15 | 0.716 | 0.039 | 5.640 | 0.534 | 24 | 0.755 | 0.055 | 6.590 | 0.584 | |
| B. lapidarius | Trivières | 8 | 0.701 | 0.059 | 4.810 | 0.567 | 22 | 0.746 | 0.047 | 6.520 | 0.534 | |
| B. lapidarius | Torgny | 16 | 0.671 | 0.052 | 5.560 | 0.564 | 22 | 0.745 | 0.052 | 6.480 | 0.643 | |
| Mean | 16.4 | 0.589 | 0.091 | 5.519 | 1.377 | 21.5 | 0.594 | 0.111 | 5.443 | 0.898 | ||
For each population the mean values (and SE) of the expected heterozygosity (HE) and the allelic richness (AR) over all microsatellite loci are given. Furthermore, species are grouped based on their distribution in Belgium. With N = the number of populations of each species.
*Allelic richness calculated based on 10 diploid specimens.