Description of the final instar larva of Orthetrum borneense Kimmins, 1936 (Odonata, Libellulidae), using rearing and molecular methods Author Steinhoff, Philip O. M. Author Butler, Stephen G. Author Dow, Rory A. text Zootaxa 2016 2016-02-18 4083 1 99 108 journal article 31397 10.11646/zootaxa.4083.1.5 72dfdae6-fad3-4c2c-9330-5b34c186f51d 1175-5326 1053687 AF2E3161-DA92-4935-BF50-4F0AA53514DF Description of the larva of Orthetrum borneense Table 3 . List of larval material examined (all from Gunung Mulu National Park, Sarawak ) Description of a male larva reared in the lab (POMS485-2014) Diagnosis (For habitus see Figs. 2 , 3 ) . A rather hairy, long legged larva; head with prominent eyes, abdomen rather elongate. FIGURE 1. Neighbour joining COI gene tree using uncorrected p–distance for adults of nine species and subspecies of Orthetrum plus two outgroup taXa, and a larva of O. borneense . TABLE 2. BOLD process ID’s, GenBank accession numbers and specimen data for COI sequences used in the analysis.

Species	Collection number	Country	Location	Collector	BOLD process ID	GenBank accession number
Orthetrum sabina	509731	Indonesia	North Sulawesi	R.A. Dow	ORBOR001- 15	KU496902
Orthetrum sabina	506581	Philippines	Davao Oriental, Mindanao	R.A. Dow	ORBOR002- 15	KU496904
Orthetrum sabina	506712	Indonesia	Palangkaraya, Kalimantan Tengah	R.A. Dow	ORBOR003- 15	KU496903
Orthetrum glaucum	5008323	Indonesia	Rama Rama, Riau, Sumatra	R.A. Dow	ORBOR004- 15	KU496891
Orthetrum glaucum	501025	Malaysia	Anap Muput, Bintulu division, Sarawak	R.A. Dow	ORBOR005- 15	KU496893
Orthetrum glaucum	500541	Indonesia	Borme, Star Mountains, New Guinea	V.J. Kalkman	ORBOR006- 15	KU496892
Orthetrum luzonicum	501150	Malaysia	Kuala Tahan, Pahang	R.A. Dow	ORBOR007- 15	KU496894
Orthetrum luzonicum	503934	Malaysia	Sekayu Recreational Forest	R.A. Dow	ORBOR008- 15	KU496895
Orthetrum borneense	506375	Malaysia	Gunung Mulu National Park, Miri division	R.A. Dow	ORBOR009- 15	KU496886
Orthetrum borneense	500034	Malaysia	Gunung Mulu National Park, Miri division	J. Simun	ORBOR010- 15	KU496887
Orthetrum borneense	503840	Malaysia	Hose Mountains, Kapit division, Sarawak	L. Southwell	ORBOR011- 15	KU496885
Orthetrum testaceum	500982	Malaysia	Farm near Lambir Hills, Miri division, Sarawak	L. Southwell and M. Kibi	ORBOR012- 15	KU496906
Orthetrum testaceum	506570	Philippines	Purok Yakal Tandang Sera, Davao Oriental, Mindanao	H. Cahilog	ORBOR013- 15	KU496907
Orthetrum testaceum	501132	Malaysia	Kuala Tahan, Pahang	R.A. Dow	ORBOR014- 15	KU496905
Orthetrum pruinosum neglectum	506386	China	Tai Tong, Hong Kong	R.A. Dow	ORBOR015- 15	KU496899
Orthetrum pruinosum neglectum	508445	China	Weidong, Guangdoong	H. Zhang	ORBOR016- 15	KU496898
Orthetrum pruinosum clelia	509458	Philippines	Between Trento and Bislig, Mindanao	H. Cahilog	ORBOR017- 15	KU496896
Orthetrum pruinosum clelia	506543	Philippines	Sodako, Davao City, Mindanao	R.A. Dow	ORBOR018- 15	KU496897
Orthetrum pruinosum schneideri	506877	Malaysia	Usun Apau National Park, Miri division, Sarawak	Y. Tegong	ORBOR019- 15	KU496900
Orthetrum pruinosum schneideri	501389	Malaysia	Gunung Kalulong, Miri division, Sarawak	M. Kibi	ORBOR020- 15	KU496901
Orthetrum chrysis	507813	Malaysia	Kampung Sebako, Kuching division, Sarawak	R.A. Dow	ORBOR021- 15	KU496890
Orthetrum chrysis	501134	Malaysia	Kuala Tahan, Pahang	R.A. Dow	ORBOR022- 15	KU496889
Orthetrum chrysis	506406	China	Tai Tong, Hong Kong	G.T. Reels	ORBOR023- 15	KU496888
Cratilla metallica	501130	Malaysia	Kuala Tahan, Pahang	R.A. Dow	ORBOR024- 15	KU496883
Epophthalmia vittigera	501281	Malaysia	Sungai Teku, Sibu division, Sarawak	G.T. Reels	ORBOR025- 15	KU496884

Head ( Figs. 2 , 3 ). Wider than long, widens from base to eyes. Eyes large, about the same length as lateral margins. Postocular lobes rounded, suboval glabrous areas longer than broad, touching hind margin. Antennae seven-segmented. Clypeus and frons well developed, labrum not visible in dorsal view but covered by palps of the spoon-shaped labium. Labium with prementum short and broad, reaching well behind the posterior margin of the front coxae ( Fig. 3 ). Prementum with an oval-shaped depression mediodorsally, a wave-shaped row of 15–20 setae on each side of the depression ( Fig. 4a ). Setae gradually shorter and more densely packed towards the depression ( Fig. 4a ). Anterior margin of prementum rounded, but pointed medially with 13 very weak crenations and several small, spine-like setae ( Figs. 2 , 3 ). Labial palps subtriangular, with seven long setae on dorsal margin and strong single end-spines ( Fig. 4a,b ). Medial margins of labial palps with ten fine rounded crenations ( Fig. 4b ). TABLE 3. List of larval material examined (all from Gunung Mulu National Park, Sarawak)

SeX	Date of collection	Location	leg.	Date of emergence	Code
unknown, early instar	12.09.2008	pool on summit trail above 1500m	J. Simun	stored in ethanol at RMNH	RMNH.INS.500034
♂	30.05.2014	Forest pool above Camp 3	POMS	0 3.06.2014	PomS469-2014
♂	30.05.2014	Forest pool above Camp 3	POMS	0 7.06.2014	PomS470-2014
♂	30.05.2014	Forest pool above Camp 3	POMS	14.06.2014	PomS485-2014
♀	0 9.07.2014	Forest pool below Camp 3	POMS	20.07.2014	PomS553-2014
♀	15.04.2014	Forest pool below Camp 3	POMS	18.04.2014	PomS235-2014
♀	15.04.2014	Forest pool below Camp 3	POMS	29.04.2014	PomS310-2014
♀	15.04.2014	Forest pool below Camp 3	POMS	between 29.04.2014 and 0 3.05.2014	PomS314-2014
♀	30.05.2014	Forest pool above Camp 3	POMS	0 7.06.2014	PomS471-2014
♀	30.05.2014	Forest pool above Camp 3	POMS	17.06.2014	PomS509-2014

Thorax ( Fig. 2 , 3 ). Prothorax narrow, in dorsal view partially obscured by long setae originating on the hind margin of the head. Synthorax covered by setae except for bare area in dorsal anterior part, and bare areas laterally between coxae. Wing cases dark with long, thin and erect setae on margins and one row of setae medially on surfaces ( Fig. 4f ). Wing cases reaching well onto the 5th segment ( Fig. 2 ). Legs with long setae on flexor and extensor margins of femora and tibiae, hind legs additionally with strong spines on flexor margins of tibiae; all tarsi with short stout spines on flexor surfaces. Abdomen ( Figs. 2 , 3 ). Moderately high in profile, rather elongate, broadest part somewhat caudally from middle. S8–9 with short lateral spines, S4–7 with very strong dorsal spines ( Fig. 4e ). Spines most strongly developed and nearly erect on S4 and S5, gradually decreasing in size rearwards ( Fig. 4e ). Spine on S4 broken off in specimen described here, but present in all other examined material ( Figs. 2 , 4e ). Dorsal spines on S5 and S6 overlap intersegmental skins ( Figs. 1 , 3e ). Dorsal spines accompanied by tufts of long setae ( Fig. 2 ). Caudal margins of S5–9 with long setae that cover intersegmental skins; lateral margins of S5–9 with short setae ( Fig. 2 ). Anal pyramid large and elongate, paraprocts slightly inward curved ( Figs. 2 , 3 , 4c,d ). Paraprocts slightly shorter than epiproct (1:1.1), cerci shorter than paraprocts (1:1.6). Margins of paraprocts and epiproct with long setae ( Figs. 2 , 3 ). Measurements (mm): Total length 32.4; paraproct length (ventral) 1.8; head width 8.2; prementum width 6.6; prementum length (ventral) 5.8. Variation among reared specimens. One female with two additional small setae on dorsal margin of right labial palp, positioned anteriorly of the seven other setae and oriented somewhat more dorsally. One female with nine instead of ten crenations on medial margin of palps. Number of weak crenations on anterior margin of prementum varies between 12 and 15 among specimens. Paraprocts as long as epiproct in females (1:1) and cerci with half the length of paraprocts in females (1:2). Dorsal spine on S 7 in some females very small and procumbent. Measurement ranges in examined specimen (n=8) (mm): Total length 29.7–33.3; paraproct length (ventral) 1.6–2.3; head width 7.7–8.5; prementum width 6.4–7.3; prementum length (ventral) 5.8–6.8. Comparison between reared specimen and the early instar matched to adults using DNA barcoding. The early instar has a less elongate shape, with the abdomen more compact than in the final instar. Setae are about the same length in the early instar as in the final instar, which gives the much smaller larva a more setose overall appearance. However, the arrangement of setae and the bare spots on the thorax are the same as in the final instar. The eyes seem somewhat more protruding in the early instar than in the final instar, but the general head form and proportions agree well. Prementum and labial palps as in final instar. Wing cases tiny with few long setae. Dorsal and lateral spines on abdomen not yet developed. Paraprocts slightly longer than epiproct, setae on base of terminal appendages as in the final instar. Measurements (mm): Total length 7.8; paraproct length 0.7; head width 2.4; prementum width 1.9; prementum length (ventral) 2.3. FIGURE 2. Orthetrum borneense ♂ eXuvia dorsal, Visionary Digital stacking photograph FIGURE 3. Orthetrum borneense ♂ eXuvia ventral, Visionary Digital stacking photograph. Habitat. Orthetrum borneense is known exclusively from the Bornean highlands above 1000 m a.s.l. Most records are from primary (but in some cases disturbed by logging) forest, but at 1600 m a.s.l. at Paya Maga in Sarawak’s Limbang Division adults were found around small pools of water in open areas (Chee Yen Choong, personal communication). At Gunung Mulu the larva inhabits shallow, shady forest pools whose substrates usually consist of many layers of leaf litter. It can often be found in large numbers at such sites. In forest pools at high altitude on Gunung Mulu, O. borneense larvae were one of only a few species found along with larvae of Indaeshna grubaueri and Coeliccia cf. nemoricola ( Steinhoff 2015 ).