Pyrgonota bifoliata
Creators: name: Lin, Chun-Yu
name: Maruyama, Munetoshi
name: Yap, Sheryl A.
name: Lin, Chung-Ping
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Membracidae
Pyrgonota
Pyrgonota bifoliata

description: Results
Identification of nymphs and host plants through DNA barcoding
A total of 910 bp and 899 bp of the mitochondrial CO1 sequences were obtained from the nymph specimens collected from Piper umbellatum (L3Cn5, GenBank accession number: ON556421) and Saurauia latibractea (L3Cn6, GenBank accession number: OQ344652), respectively, at the field site. The CO1 sequences of the nymph specimens from the two host plant specimens were identical to those of the three adult P. bifoliata specimens (sp. 1) collected from Mount Makiling in an earlier study (GenBank accession numbers: KC848075.1–KC848077.1, Su et al. 2014), confirming the species identity of the nymph. The ITS sequence of the major host plant, P. umbellatum, was 669 bp (GenBank accession number ON556419), which matched the ITS sequences of P. umbellatum in BLASTn searches (similarity: 100%; GenBank accession number: EF060088.1).
Host plants
A total of 27 nymphs and 28 adults of P. bifoliata were observed in the Mount Makiling Forest Reserve. Piper umbellatum L. (Piperaceae) and Saurauia latibractea Choisy (Actinidiaceae) were used by 17 (63%, seven plants) and 10 (37%, two plants) nymphs, respectively (Figure 2). Nymphs of various instars and their exuviae were found on both P. umbellatum and S. latibractea (Figure 3f, h). One nymph successfully eclosed on a netted branch of S. latibractea on day 12 of the study period. Adults were mainly found on three plant species: Alangium longiflorum Merr. (Cornaceae) (9/28, 32%), Ficus ulmifolia Lam. (Moraceae) (6/28, 21%) and P. umbellatum (5/28, 18%) (Figure 2; Table S1). Four additional, less common plant species were also recorded as adult hosts: Rubiaceae sp. (3/28, 11%), S. latibractea (2/28, 7%), Pterocarpus indicus Willd. (Fabaceae) (1/28, 4%) and Annonaceae sp. (1/28, 4%) (Figures 2 and S 1; Table S1). During the study period, five of the 28 adults were observed between two and six times. These five adults were repeatedly observed on A. longiflorum, F. ulmifolia and P. umbellatum within 20 days of the study period. Field notes are presented in Table S1 (see Supplementary Materials).
Observations of behaviours and ant attendance
The females of P. bifoliata in the Mount Makiling Forest Reserve were not observed to exhibit maternal care behaviours similar to those of subsocial treehoppers, such as egg or nymph guarding (Wood 1993; Stegmann and Linsenmair 2002; Lin 2006). The size of the nymph aggregations of P. bifoliata ranged from one to five individuals on P. umbellatum (mean ± standard deviation [SD] = 2.4 ± 1.3, n = 7) and from three to seven individuals (mean ± SD = 5 ± 2, n = 2) on S. latibractea. Ants visited more than half (5/9, 56%) of these nymph aggregations. However, no correlation was found between the size of the nymph aggregation and the presence of ants (logistic regression, p = 0.525, n = 9). Three ant species, Crematogaster sp., Pheidole sp. and Technomyrmex sp., visited the nymphs of P. bifoliata at the study site. A few attending ants touched the bodies of the nymphs with their antennae and legs. No marked behavioural response from the nymphs, such as movement of the tubular segment IX or secretion of honeydew, was observed in the presence of ants (Figure 3c–h). Ants did not attend any of the observed adult P. bifoliata. Two crab spiders (Thomisidae) were observed near the nymphs without any predatory attack on the two branches of P. umbellatum plants for a few days (Figure 3e). One of the crab spiders captured a visiting Technomyrmex ant.
Morphological description
No morphological variation was observed among nymphs collected from P. umbellatum and S. latibractea.
Last-instar nymph
Overall body. Colour green when alive, and yellowish when preserved. Cross section subtriangular, slightly compressed laterally. Chalazae densely covered throughout the entire body. Dorsal contour of abdomen linear in lateral view. Overall body in dorsal view elongate (longer than wide).
Head. Vertex with a pair of enlarged chalazae (Figure 4a). Chalazae consist of a tuberculate base with needle- or hair-like seta. A pair of round protuberances present anteriorly, and the chalazal setae on the protuberances longer (Figure 4a). Compound eye surface setae present. Frons not extended over central margin of eye.
Prothorax. Premetopidium with a pair of enlarged chalazae directed dorsalanteriorly (Figure 4a). Postmetopedium elevated and carinate. Metopidial sulcus weakly incised (Figure 4d). Posterior extension of pronotum narrowly convex, not surpassing anterior margin of metanotum. Dorsal pronotal single medial horn bud absent. Pronotal lateral margin emarginate carinate. Suprahumeral horn bud carinate apically (Figure 4b).
Mesothorax. Two pairs of large chalazae present near posterior extension of pronotum (Figure 4d). Forewing pad densely covered with short chalazae, chalazal setae short. Forewing pad costal chalazae only present on base of costal margin. Ventral margin of forewing pad emarginated anteriorly (where hind leg is placed).
Metathorax. Scoli absent. A pair of enlarged chalazae present dorsally (Figure 4b). Dorsal posterior margin with paired carinae (Figure 4c).
Legs. Chalazae of tibia on lateral margins and many on dorsal surface. Prothoracic tibia dorsally flattened, slightly extended anteriorly. Metathoracic tarsal length subequal to prothoracic and mesothoracic tarsal length. Prothoracic and mesothoracic first tarsomeres distinctly shorter than second tarsomeres. Metathoracic first tarsomere subequal to second tarsomere.
Abdomen (labelled abdominal segments). Tergum I with a pair of digitate tubercles protruding from metanotum carina (Figure 4c). Tergum II flat, forming a pair of triangular protuberances with a chalaza at the tip (Figure 4c). Terga III–VIII with ventrolateral lobe-like lamellae directed obliquely posterior-laterally. Lamellar chalazae dense marginally and dorsally, with only two short chalazae present ventrally (Figure 4f). Terga III–VIII dorsal scoli short, subequal in size. Tergum IV dorsal scoli directed obliquely dorsal-posteriorly. Terga III–VIII with large chalazae forming one lateral row on each side (Figure 4d).
Tubular segment IX. Chalazae densely covered. Shape of distal to pregenitalia in crosssection subcircular. Dorsal length subequal to combined length of segments V–VIII. Ventral extension subequal to dorsal extension.
Anal apparatus (segment X, XI). Segment X white, length subequal to segment XI. Segment XI black-white-black anterior-posteriorly, with hairs present near the white tip.
Material examined. 4 nymphs (specimen codes: L3 Cn 1, L3 Cn 3, L3 Cn 5, L3 Cn 6), Mount Makiling, Los Baños, Laguna Province, Philippines, 12. II. 2019, Chun-Yu Lin leg.; 2 nymphs (specimen codes: L3 Cn 2, L3 Cn 4), Mount Makiling, Los Baños, Laguna Province, Philippines, 30 January 2019, Chun-Yu Lin leg.
description: Published as part of Lin, Chun-Yu, Maruyama, Munetoshi, Yap, Sheryl A. & Lin, Chung-Ping, 2024, Host plants and nymph morphology of an endemic treehopper, Pyrgonota bifoliata, in the Mount Makiling Forest Reserve, Luzon, Philippines, pp. 270-284 in Journal of Natural History 58 (5 - 8) on pages 274-279, DOI: 10.1080/00222933.2024.2314965, http://zenodo.org/record/10818650