Myrmeleon taiwanensis Miller and Stange, 1999

Lin, Yu-Hsiu, Liao, Jhih-Rong & Ko, Chiun-Cheng, 2021, Fig. 5 in Periclimenaeus karantina Park & De Grave 2021, sp. nov., Zoological Studies 60 (39), pp. 1-24 : 19

Myrmeleon taiwanensis Miller and Stange, 1999

( Figs. 3H , 4H , 13 )

Description of 3rd instar larva: Size: Average body length 7.68 mm (6.35–8.52); head length 1.82 mm (1.69–1.99), head width 1.56 mm (1.48–1.67), mandible length 1.90 mm (1.68–2.10), ratio head width/length 0.85, ratio mandible length/head length 1.04.

General coloring: Pale orche, with brown body markings.

Head: Sub-rectangular, longer than wide. Covered with short, black setae. Ocular tubercle sessile. Mandibles pale brown with apex reddish, as long as the head capsule, provided with 3 equidistant teeth with the apical tooth slightly stronger. Interdental mandibular setae: (4–7)(2–4)(2)(1). Clypeo-labrum with pointed setae. External margin of the mandible with a fringe of long setae, dorsal side of the mandible with a row of short setae along the external margin, ventral side of the mandible without setae. Labial palpus 3-articulated, with fringe of black setae underneath, few extending over labial palpus. Dorsal side of the head capsule with the clypeo-labrum dark brown, the anterior side with a pair of dark brown spots, followed by a pair of brown stripes, touching with brown markings on the lateral margins. Lateral side of the head with a small pale brown spot on the dorsal-posterior side. Ventral side of the head with a dark brown marking on the clypeo-labrum, a pair of brown spots slightly posterior to the middle.

Thorax: Pronotum with a pair of lateral brown stripes, covered with short setae. Body setae black.

Legs: Pale brown, unspotted.

Abdomen: Setae black. VIII abdominal sternite with a pair of pale brown markings, odontoid processes distinct, posterior margin with short filiform setae. IX abdominal sternite with a median row of 4 peg-like digging setae. Rastra sessile, each bearing 3 stout, peg-like digging setae equal in size, 1 seta on the external side.

Materials examined: Taiwan. Pingtung County. Baishawan, Hengchun Township / 04. II. 2020 / Y. H. Lin leg., 4 L3 laboratory reared to adult. Dawan Beach, Hengchun Township / 03. II. 2020 / Y. H. Lin leg., 2 L3 laboratory reared to adult. Fengchuisha Beach, Hengchun Township / 29. IX. 2019 / Y. J. Tsao leg., 3 L3; same locality / 03. II. 2020 / Y. H. Lin leg., 2 L3, 4 L3 laboratory reared to adult. Gangkou beach, Manzhou Township / 03. II. 2020 / Y. H. Lin leg., 3 L3, 3 L3 laboratory reared to adult. Jiupeng Desert, Manzhou Township / 04. II. 2020 / Y. H. Lin leg., 2 L3 laboratory reared to adult. Taitung County. Shuangshiyan, Lanyu Township / 14. VII. 2020 / Y. H. Lin leg., 3 L3. Yeyin Beach, Lanyu Township / 15. VII. 2020 / Y. H. Lin leg., 1 L3, 1 L3 laboratory reared to adult; same locality / 16. VII. 2020 / Y. H. Lin leg., 2 L3 laboratory reared to adult. Yeyou River mouth / 17. VII. 2020 / Y. H. Lin leg., 1 L3, 1 L3 laboratory reared to adult.

Bio-ecology: M. taiwanensis is a coastal species. The larvae builds pitfall in protected sites, and they are often found in wind-break forests, and also under rock overhangs of rocky shores ( Fig. 1C ). The larvae of M. taiwanensis may co-habitat with those of M. littoralis .

Distribution: M. taiwanensis is found by the coast in the southern parts of Taiwan, including the surrounding island - Lanyu. This species is also recorded in Okinawa Island, Iriomote Island, Ishigaki Island and Yonaguni Island of Japan ( Sekimoto 2014, Hayashi et al. 2020).

Remarks: The larvae of this species are similar to M. littoralis in overall morphology and ventral head markings. The two species can be distinguished by the shape of dorsal head markings, presence of markings on the ventral side of the clypeo-labrum, and the segmentation of the labial palpus (three-segmented in M. taiwanensis ).

Hayashi et al. (2020) also described the larvae of this species from Japan, stating that there are no clear differences between the Japanese and Taiwanese specimens.

Figures

Fig. 3. Head of 3rd instar larvae of Myrmeleontini of Taiwan, ventral view; A, Baliga asakurae; B, Myrmeleon alticolus; C, Myrmeleon bimaculatus; D, Myrmeleon heppneri; E, Myrmeleon littoralis; F, Myrmeleon persimilis; G, Myrmeleon punctinervis; H, Myrmeleon taiwanensis; I, Myrmeleon wangi. Scale bar = 1 mm.

Fig. 4. IX abdominal sternite of 3rd instar larvae of Myrmeleontini of Taiwan, ventral view; A, Baliga asakurae; B, Myrmeleon alticolus; C, Myrmeleon bimaculatus; D, Myrmeleon heppneri; E, Myrmeleon littoralis; F, Myrmeleon persimilis; G, Myrmeleon punctinervis; H, Myrmeleon taiwanensis; I, Myrmeleon wangi. Scale bar = 1 mm.

Fig. 13. Myrmeleon taiwanensis Miller and Stange, 1999, 3rd instar larva. A, dorsal view; B, ventral view; C, lateral view.

Fig. 1. Habitats of the Myrmeleontini larvae, A, Underneath trunks of giant woods (M. alticolus). B, On open sand dunes (M. persimilis). C, Underneath rock overhangs (M. taiwanensis). D, Underneath artificial buildings (M. wangi).