Larval Description and Phylogenetic Placement of the Australian Endemic Genus Barretthydrus Lea, 1927 (Coleoptera: Dytiscidae: Hydroporinae: Hydroporini: Sternopriscina) Author Alarie, Yves Author Michat, Mariano C. Author Hendrich, Lars Author Watts, Chris H. S. text The Coleopterists Bulletin 2018 2018-12-28 72 4 639 661 http://dx.doi.org/10.1649/0010-065x-72.4.639 journal article 5023 10.1649/0010-065X-72.4.639 6c68ffec-a5cc-4d0e-88d0-eeb1ba6c8130 1938-4394 4789513

Table 1. Measurements and ratios for the larvae of Barretthydrus tibialis (BATI) and Barretthydrus geminatus (BAGE). n = number of specimens studied; ** = missing values. See text for definitions of variable codes.

	BATI		BAGE
Variables	Instar I (n = 1)	Instar III (n = 12)	Instar III (n = 4)
HL (mm)	0.60	1.24–1.30	1.27–1.36
HW (mm)	0.49	0.96–1.02	0.94–1.02
FRL (mm)	0.48	0.97–0.99	1.01–1.05
OCW (mm)	0.34	0.56–0.65	0.56–0.63
HL/HW	1.23	1.24–1.35	1.33–1.35
HL/LAS	4.61	3.91–4.47	4.63–4.66
HW/OCW	1.44	1.57–1.70	1.60–1.69
A/HW	0.83	0.70–0.73	0.75–0.77
A3/A2	1.33	0.84–1.00	0.87–0.88
A4/A3	0.62	0.31–0.38	0.30–0.35
A3’/A4	0.81	0.76–0.92	0.76–0.98
MNL/MNW	3.78	3.74–4.31	3.95–4.74
MNL/HL	0.53	0.50–0.56	0.52–0.59
A/MP	1.13	1.02–1.07	1.00–1.02
MP2/MP1	1.48	0.86–1.00	0.90–0.92
MP/LP	1.24	1.20–1.24	1.16–1.25
LP2/LP1	1.60	0.81–0.95	0.81–0.94
L1 (mm)	1.15	2.09–2.19	2.03–2.13
L2(mm)	1.33	2.51–2.69	2.41–2.53
L3 (mm)	**	2.94–3.09	2.80–2.96
L3/L1	**	1.37–1.42	1.36–1.39
L3/L2	**	1.11–1.18	1.15–1.17
L3/HW	**	2.98–3.15	2.96–3.05
L3(CO/FE)	**	0.90–0.94	0.91–0.92
L3(TI/FE)	**	0.73–0.77	0.70–0.75
L3(TA/FE)	**	0.70–0.80	0.71–0.76
L3(PC/TA)	**	0.34–0.38	0.35–0.36
LAS (mm)	0.13	0.28–0.34	0.28–0.30
LAS/HW	0.27	0.28–0.35	0.29
U1 (mm)	0.75	1.51–1.69	1.29–1.45
U1+U2’(mm)	1.05	1.99–2.19	**
U1+U2 (mm)	1.14	**	**
U1/U2’	2.53	2.87–3.33	**
U1/LAS	5.79	4.63–6.08	4.56–5.12
U1/HW	1.55	1.56–1.67	1.37–1.49
U1+U2’/LAS	8.08	6.68–7.90	**
U1+U2’/HW	2.17	2.11–2.13	**
U1+U2/LAS	8.76	**	**
U1+U2/HW	2.35	**	**