Shared patterns of population genomic variation and phenotypic response across rapid range expansions in two invasive lady beetle species

Abstract

Non-native lady beetle species have often been introduced, with variable success, into North America for biological control of aphids, scales, whiteflies, and other agricultural pests. Two predatory lady beetle species, Propylea quatuordecimpunctata and Hippodamia variegata, both originating from Eurasia, were first discovered near Montreal, Quebec, in North America in 1968 and 1984, respectively, and have since expanded into northeastern North America and the midwestern United States. In this study, we estimate the range-wide population structure, establishment and range-expansion, and recent evolutionary history of these species of non-native lady beetles using reduced representation genotyping-by-sequencing via ddRADseq. In addition, we quantified the responses to a key abiotic factor, photoperiod, that regulates adult reproductive diapause in these two species and may influence their latitudinal distribution and spread in North America. Our analyses detect (1) non-significant genetic differentiation and divergence among North American populations, (2) evidence of reduced contemporary gene flow within the continental US, (3) significant phenotypic differences in diapause induction despite genetic similarities across sampled populations. Key Words: population genomics, invasive species, biological control, diapause

Go west: Population genomics reveals unexpected population fluctuations and little gene flow in Western hemisphere populations of the predatory lady beetle, Hippodamia convergens

“…Genetic data are important sources of information for gaining insight into historical and recent evolutionary history of species that have had their populations established or augmented by large-scale releases of individuals, as occurs during biological control (Jones et al, 2023;Kajita et al, 2012;Li et al, 2019Li et al, , 2020Li et al, , 2021Li et al, , 2023Sentis et al, 2022;Sethuraman et al, 2020;Wang et al, 2023).…”

“…While population augmentations can be demographically and economically beneficial, they can also adversely impact intraspecific genetic variation by causing the breakdown of local adaptations, loss of genetic variability, and the reshaping of population structure (Laikre et al., 2010; Simberloff & Stiling, 1996; Terui et al., 2023; Wajnberg et al., 2001). Genetic data are important sources of information for gaining insight into historical and recent evolutionary history of species that have had their populations established or augmented by large‐scale releases of individuals, as occurs during biological control (Jones et al., 2023; Kajita et al., 2012; Li et al., 2019, 2020, 2021, 2023; Sentis et al., 2022; Sethuraman et al., 2020; Wang et al., 2023). Population genomics, in particular, provides a powerful approach toward understanding how genetic variation has been impacted on a recent time scale (Maigret et al., 2020; Nunziata et al., 2017), including the time frame encompassing human‐mediated movements and augmentations of populations during biological control.…”

Go west: population genomics reveals unexpected population fluctuations and little gene flow in Western Hemisphere populations of the predatory lady beetle,Hippodamia convergens

“…Genetic data are important sources of information for gaining insight into historical and recent evolutionary history of species that have had their populations established or augmented by large-scale releases of individuals (Kajita et al, 2012, Li et al, 2019, Sethuraman et al, 2020, Sentis et al, 2022, Jones et al, 2023. Population genomics, in particular, provides a powerful approach towards understanding how genetic variation has been impacted on a recent time scale (Nunziata et al, 2017;Maigret et al, 2020), including the time frame encompassing human-mediated movements and augmentations of populations.…”