Phylogeography of the endemic red-tailed cicadas of New Zealand (Hemiptera: Cicadidae: Rhodopsalta), and molecular, morphological and bioacoustical confirmation of the existence of Hudson’s Rhodopsalta microdora
Author
Bator, John
Author
Marshall, David C
Author
Hill, Kathy B R
Author
Cooley, John R
Author
Leston, Adam
Author
Simon, Chris
text
Zoological Journal of the Linnean Society
2022
2022-08-01
195
4
1219
1244
https://academic.oup.com/zoolinnean/article/195/4/1219/6365998
journal article
121332
10.1093/zoolinnean/zlab065
812a47cb-8654-4d5e-90af-fac9fe237911
0024-4082
6985713
Rhodopsalta microdora
This species comprises three main clades. The southern SI clade is composed of specimens from North
Canterbury
(NC), Mid
Canterbury
(MC), South
Canterbury
(SC), Mackenzie region (MK) and Central
Otago
(CO). It is sister to an eastern clade made up of a Kaikoura group (SI) + mixed SI/NI clade composed of specimens from
Marlborough
(MB) (SI) and Rangitikei, Taupo and
Hawkes Bay
(NI) districts (
Figs 4
,
5A
).
GENETIC DISTANCES
Corrected (patristic) and uncorrected genetic distances from the
cox1
locus are presented in the Supporting Information (Table S4). Average uncorrected distances between the three species groups are as follows:
Rhodopsalta cruentata
–
R. leptomera
, 0.031;
R. cruentata
–
R. microdora
, 0.047; and
R. microdora
–
R. leptomera
, 0.047. Average uncorrected intraspecific distances were near zero among populations of eastern NI
R. leptomera
and largest among populations of SI
R. microdora
(≤ 0.040). As a whole,
R. microdora
had the greatest intraspecific average distance (0.019) and
R. leptomera
the least (0.003) (Supporting Information, Table S5).
MOLECULAR CLOCK DATING
The *BEAST multispecies coalescent analysis estimated that
Rhodopsalta
diverged from its sister genera,
Maoricicada
and
Kikihia
, between ~5 and 20 Mya (mean 11.6 Mya; see interspecific divergence dates plotted in
Fig. 4
). The wide confidence interval reflects the uncertainty encoded in the
cox1
molecular clock prior. The earliest split in the
Rhodopsalta
clade is the split between
R. microdora
and the ancestor of
R. cruentata
and
R. leptomera
, with a mean estimate of 5.5 Mya (
Fig. 4
).
Rhodopsalta leptomera
diverged from
R. cruentata
between 0.8 and 3.6 Mya (mean 2.0 Mya).
Although *BEAST cannot be used to estimate dates within assumed populations (species), we present the dated mtDNA gene tree from this analysis (
Fig.7
), which can be used to obtain approximate divergence times for geographically coherent intraspecific clades that might correspond to diverging, isolated populations (keeping in mind that this violates the *BEAST model assumptions, as discussed later in this paper). Note that mtDNA clade divergence dates necessarily overestimate any corresponding population splits to an unknown degree, which adds to the uncertainty (
Edwards & Beerli, 2000
). The three deepest
cox1
subclades within
R. microdora
diverged during the Pliocene to early Pleistocene (
Fig. 7
). The mean estimated divergence date for the split of the central-eastern SI clade from the ancestor of the Kaikoura and
Hawkes Bay
clades is 2.8 Mya, and the mean estimated date for the Kaikoura/
Hawkes Bay
split is 2 Mya, about the time
R. leptomera
split from
R. cruentata
. North Island
R. cruentata
split from SI
R. cruentata
between 0.5 and 2.5 Mya (mean 0.9 Mya). These date estimates involve additional uncertainty, which is not reflected in the wide confidence intervals, owing to choice of priors and potential violations of model assumptions (see Discussion).