Fig 1.
Collection localities of New Zealand Eucolaspis beetles used in this study.
Closed circles represent sampling locations. Inset maps show details of more intensely sampled regions. Relevant localities and regions are indicated. Sampled ecological regions include ¶Northern North Island, ‡Central Volcanic Plateau, *Axial Ranges, †Windward Districts and §Leeward Districts.
Fig 2.
External and internal morphological characters of Eucolaspis assessed.
(A) Eucolaspis (Coleoptera: Chrysomelidae) (modified from Des Helomore’s drawing of Eucolaspis brunnea (Fabricius)). Scale bar = 1mm. Insets show puncturation on pronotum (top) and elytra (below). Insets are not to scale. Morphometric measurements recorded are labeled: BL- body length (mm); BW- body width (mm); AL- antenna length(mm); EL- eltyra length (mm); EW- elytra width (mm); PL- pronotum length (mm); HPD- puncture density on the head (mm-2); PPD- puncture density on the pronotum (mm-2); AEPD- punctures density on anterior half of the elytra (mm-2); PEPD- punctures density on posterior half of the elytra (mm-2). (B) Aedeagus from a male Eucolaspis beetle collected on apple at Havelock North, New Zealand: a–aedeagus proper; b–tegmen; c–basal hood; d–ejaculatory sac; e–median ejaculatory duct.
Table 1.
Sexual dimorphism in New Zealand Eucolaspis beetles.
Data from representative individuals among fresh beetle samples collected throughout New Zealand. BL Body length, BW body width, EL elytra length, EW elytra width, AL antennae length, PL pronotum length, HPD head puncture density, PPD pronotal puncture density, AEPD anterior elytral puncture density, PEPD posterior elytral puncture density.
Fig 3.
Canonical Discriminant analysis for Eucolaspis morphometric data.
Can1 and Can2 are the first two canonical variables. (A) Morphometric relationships among Eucolaspis beetles collected from different ecological regions across New Zealand. (B) Morphometric relationships among identified voucher Eucolaspis specimens in NZAC collection: variation among the samples independently diagnosed to species. (C) Morphometric relationships among male Eucolaspis beetles with three different aedeagei types. (D) Morphometric relationships among the three mainland New Zealand genetic lineages of Eucolaspis (Lineages 1, 2 and 3).
Fig 4.
Bayesian phylogeny of New Zealand Eucolaspis (COI region of mtDNA) using GTR+G+I model.
SBL = 0.924967. Node labels indicate posterior probabilities, and tip labels indicate corresponding taxon. Images of male genitalic aedeagus tip shape corresponding to each lineage are shown.
Table 2.
Species delimitation analysis confirms monophyly of the thee mainland New Zealand lineages of Eucolaspis.
Inter Dist closest = mean pairwise tree distance between the members of the focal species and members of the next closest species; P ID(strict) = mean probability of correctly identifying an unknown specimen of the focal species using placement on a tree sequence; Av (MRCA) = mean distance between the most recent common ancestor of a species and its members; P (randomly distinct) is the probability that a lineage has the observed degree of distinctiveness due to random coalescent processes. Input tree was constructed by Bayesian inference method using GTR+G+I model.
Fig 5.
Frequency distribution of pairwise genetic distances (P-distances) among New Zealand Eucolaspis haplotypes.
P-distances are calculated as number of nucleotide base differences per site between sequences. Grey bars represent pairwise intra-lineage distances whereas black bars represent pairwise inter-lineage distances.
Table 3.
Estimates of net evolutionary divergence between groups of Eucolaspis mtDNA (COI) sequences.
The number of base substituions per site from estimation of net average between groups of sequences are shown. P-distances (lower triangular half of the table) and Maximum Likelihood (ML) distances (upper triangular half of the table) are shown. Standard errors were calculated through bootsrap procedures (500 replicates). ML analyses were conducted using the Tamura 3-parameter (T92) model [37]. The rate variation among sites was modeled with a gamma distribution (shape parameter = 0.15). Evolutionary analyses were conducted in MEGA6 [31].
Fig 6.
Geographical distribution of Eucolaspis lineages in mainland New Zealand.
Total haplotype network structure (left) comprises three main lineages; yellow: Lineage1, orange: Lineage 2, green: Lineage 3. Dark circles on the map represent sampling sites with the distribution of haplotypes of each lineage (right) in broad regions. Regional entomological codes [38] are: AK-Auckland, ND-Northland, CL- Coramandel, BP-Bay of Plenty, GB-Gisborne, TO- Taupo, WO-Waikato, HB- Hawkes Bay, WA- Wairarapa, WI- Wanganui, WI Wellington, Pink: MB- Marlborough, NN- Nelson, KK- Kaiukoura. Size of the node (networks on the right) denotes number of haplotypes found.
Fig 7.
Bayeseian analyiss of mtDNA COI (~700 bp) from New Zealand and international Eumolpinae genera (Chrysomelidae) using a GTR+G+I model.
SBL = 3.617. Node labels indicate posterior probability support, and tip labels indicate corresponding taxon. Mainland New Zealand Eucolaspis lineages are colour coded: Yellow- Lineage 1; Orange- Lineage 2; Green- Lineage 3.