Long-term population persistence of flightless weevils (Eurhoptus pyriformis) across old- and second-growth forests patches in southern Appalachia

Abstract Background Southern Appalachian forests are dominated by second-growth vegetation following decades of intensive forestry and agricultural use, although some old-growth patches remain. While it’s been shown that second-growth areas may exhibit comparable species richness to old-growth in the area, the extent to which populations of arthropods in second-growth areas have persisted vs. recolonized from other areas remains unexamined. The implications for conservation of both classes of forest are significant. Here we analyze population diversity and relatedness across five old-growth and five second-growth populations of flightless, leaf litter-inhabiting beetles in the genus Eurhoptus (Coleoptera: Curculionidae: Cryptorhynchinae). Our main goal is asking whether second-growth areas show diminished diversity and/or signals of recolonization from old-growth sources. Results Population genetic and phylogenetic analyses do not reveal any consistent differences in diversity between the old-growth and second-growth populations examined. Some second-growth populations retain substantial genetic diversity, while some old-growth populations appear relatively depauperate. There is no phylogenetic indication that second-growth populations have recolonized from old-growth source populations. Conclusions Most populations contain substantial and unique genetic diversity indicating long-term persistence in the majority of sites. The results support substantial resilience in second-growth populations, though the geographic scale of sampling may have hindered detection of recolonization patterns. Broad scale phylogeographic patterns reveal a deep break across the French Broad River basin, as has been reported in several other taxa of limited dispersal abilities. In Eurhoptus this break dates to ~ 2–6 Ma ago, on the older end of the range of previously estimated dates

Fig. 4 in Intraspecific Diversity and Phylogeography in Southern Appalachian Dasycerus carolinensis (Coleoptera: Staphylinidae: Dasycerinae)

Fig. 4. Bayesian phylogram for DASYCerUS CArolinenSiS based on COI alone, including only unique haplotypes.Taxon names include unique extraction number (SSMxxx) and COI haplotype number, corresponding to those in Fig. 5 (coixx). Colors of names are keyed to localities as shown in map inset.Taxa representing geographic areas are indicated by W1,W2, and NE, as described in text, and as outlined on the map inset. Bayesian posterior probabilities\u3e60% are shown on branches

Fig. 5 in Intraspecific Diversity and Phylogeography in Southern Appalachian Dasycerus carolinensis (Coleoptera: Staphylinidae: Dasycerinae)

Fig. 5. Individual haplotype/allele networks based on all DASYCerUS individuals, for COI (top half) and CAD alleles (bottom half). Northeastern (NE) and western (W1 and W2) clades as discussed in the text are outlined. Allele/haplotype numbers for each gene match those in Fig. 3 (CAD) and 4 (COI) trees, respectively. Circle and pie-chart colors indicate localities of origin (see map inset). Circle and pie-chart sizes are proportional to number of individuals with that allele/ haplotype in each population. Small black circles indicate mutations

Additional file 3: of Long-term population persistence of flightless weevils (Eurhoptus pyriformis) across old- and second-growth forests patches in southern Appalachia

Combined data file for analysis in nexus format. (NEX 421 kb

Fig. 3 in Intraspecific Diversity and Phylogeography in Southern Appalachian Dasycerus carolinensis (Coleoptera: Staphylinidae: Dasycerinae)

Fig. 3. Bayesian phylogram for DASYCerUS CArolinenSiS based on CAD alone, including only unique alleles. Names of terminals represent CAD allele number, corresponding to those in Fig. 5 (DcaCADxx). Colors of names are keyed to localities as shown in map inset.Taxa representing geographic areas are indicated by W1, W2, and NE, as described in text, and as outlined on the map inset, though none strictly form clades under CAD alone. (\u27Misplaced\u27 alleles are marked with asterisks.) Bayesian posterior probabilities\u3e60% are shown on branches

Fig. 2 in Intraspecific Diversity and Phylogeography in Southern Appalachian Dasycerus carolinensis (Coleoptera: Staphylinidae: Dasycerinae)

Fig. 2. Combined data (COI + CAD) Bayesian phylogeny, including all unique DASYCerUS individuals. Taxon names represent extraction numbers. Colors of names are keyed to localities as shown in map inset. Numbers on branches indicate posterior probabilities. NE, W1, and W2 refer to northeastern, western 1, and western 2 major clades as discussed in the text, and as outlined on the map inset. Estimated ages (MYBP) are shown at major nodes, with 95% confidence intervals in purple

aligned mtDNA sequences for 125 stick insects

Fragments of COI and COII mtDNA sequence from 125 individuals of the New Zealand stick insect Clitarchus hookeri. This FASTA format file is the full alignment used for phylogenetic reconstruction. Subsets of the data used for molecular clock analysis and network analysis. Codes identify individuals, location information provided in the associated paper. Representatives of unique haplotypes are on genbank

stick insect genotypes for dryad

Genotypes for stick insect population samples for 10 microsatellite loci are provided. Collection location, code and sex of each individual stick insect is provided. Loci codes are explained in Myers et al. 2017 (https://doi.org/10.1111/jbi.13004) All specimens are Clitarchus hookeri, a species endemic to New Zealand, but with a newly established population in the UK