Fig. 2: The relationship between diploid brood viability and distance from the range centre.
From: Serial founder effects slow range expansion in an invasive social insect
A–C Locations of colonies collected in an expanding invasive population of Apis cerana in 2012, 2015 and 2019/2020 colour-coded by the relative proportion of diploid brood (DMP) per colony that are inviable ‘diploid males’ (0–50%; yellow-blue). The estimated range edge of the population per year (2012, 2015 and 2020) is shown by the dotted line. In total, six colonies (1–6) were sampled at range edges: three at the northern edge, two at the southern edge and one at the western edge (note (6) was collected in July 2022). D The proportion of diploid male brood produced per colony and the distance the colony was found from the centre of the population (n = 74 colonies). Distance is represented as a proportion of the maximum distance between the predicted range edge and the point of incursion (range centre) at the time of colony collection. The grey regions surrounding the regression line indicates the 95% CI of regression. Range edge colonies 1–6 are indicated.
