Paraplea frontalis (Fieber, 1844)

Cook, Jerry L., Sites, Robert W. & Vitheepradit, Akekawat, 2020, The Pleidae (Hemiptera, Heteroptera) of Thailand, with the descriptions of two new species and a discussion of species from Southeast Asia, ZooKeys 973, pp. 35-68 : 35

Paraplea frontalis (Fieber, 1844) Figures 1 , 2 , 3 , 4-5 , 24A

= Ploa frontalis Fieber, 1844: Entomol. Monogr. p. 18.

= Plea frontalis : (Kirkaldy, 1898): Wien. Entomol. Zeit. 17: 141.

= Plea pelopea Distant, 1911: Fauna Brit. India 5: 336-337 (synonymized by Lundblad 1933: 138).

= Plea quinquemaculata Lundblad, 1933: Arch Hydrobiol. 12: 135-138 (synonymized by Nieser 2004: 82).

Plea (Paraplea) frontalis : Esaki and China 1928: Rev. Esp. Entomol. 4: 166 (subgenus description).

Paraplea frontalis : Drake and Maldonado-Capriles 1956 (elevation to genus) 51: 53.

Remarks.

Paraplea frontalis was described as Ploa frontalis by Fieber (1844) for specimens collected in the East Indies. The original description was not extensive and relied heavily on coloration, which has proven to be a somewhat variable character in pleids. However, this description included a documentation of the distinctive markings of the face and vertex that is found in most specimens of this species. The figures provided with the original description are not very helpful in distinguishing P. frontalis from other pleid species. No types were designated by Fieber; however, the distinctive markings of the head made associations with subsequent collections possible with a relatively high degree of certainty. Kirkaldy (1898) reported on a specimen from Rangoon (now Yangon) in present day Myanmar (Burma), and in this and his later publication ( Kirkaldy 1904), he followed Leach (1817) in putting all of Pleinae into the genus Plea , thus changing the name of this species to Plea frontalis . Kirkaldy (1904) also included a range extension of the species into Bengal, which is now in Bangladesh, although it is possible that he did not distinguish between West Bengal and East Bengal, leaving uncertainty to the exact region, which would now be in either India or Bangladesh, respectively. Kirkaldy also reported specimens from Pondicherry (India) and Cochin, China, which is now in Vietnam. Kirkaldy did not provide a description of the specimens he included in P. frontalis . Distant (1906) provided an English translation of the original description by Fieber but stated that he was unable to view any specimens of the species. Distant (1910) described a species from Calcutta and Madupur, West Bengal, India as Plea pelopea based primarily on coloration, including having a head with four dark spots and commented that he thought this could be an "extreme variety" of Plea pallescens . Plea (Paraplea) pelopea was considered by Lundblad (1933) to be the same as P. frontalis , although there was no type available for comparison. Lundblad (1933) determined that all previous treatments of P. frontalis did not allow for precise identifications. He commented on the most common head marking of having five dark markings and provided drawings of the head, antenna, legs, pronotum, sternal crest and parameres, but he did not provide a complete re-description. Lundblad (1933) also described a new species, Plea (Paraplea) quinquemaculata , which is now considered a synonym of P. frontalis ( Nieser 2004). Benzie (1989) redescribed the species using specimens from Sri Lanka, including many of the characters used for modern descriptions in this family. Although all of these forms are now included as P. frontalis , it is possible that this represents a species complex. Below is a supplemental description of the species, based primarily on specimens from Thailand that fit within P. frontalis as it is currently defined.

Type information.

No holotype is designated. Fieber (1844) reported that the description was made from specimens collected by Dr. Helfer in the East Indies, although the exact location in this region of Southeast Asia is not documented in the literature. A specimen of Pleidae collected by Dr. Helfer is deposited the National Museum in Prague (NMPC) that could give an indication about the area where the original P. frontalis was collected (Nico Nieser communication). This specimen could become a neotype if it is determined to be P. frontalis , however this specimen has not yet been evaluated.

Supplementary description.

All measurements are given in millimeters from 456 adult specimens from throughout Thailand as reported in the distribution portion of this paper. Specimens used for this description are deposited at SEMC, SHSU, and UMC. Other specimens from Thailand and areas outside Thailand were surveyed but were not included in measurements due to condition or availability.

Body size. Total length, 1.89-2.32 (average 2.07) in Thailand specimens. Fieber (1844) reported total length of 2, but Lundblad (1933) reported that the species could reach 2.3 to 2.5. Greatest body width in Thailand specimens, 0.92-1.28 (average 1.04); BSI, 50-58.

Color. Color may vary among individuals (Fig. 1A, D ). Base color of body ranges from light brown to almost cream-colored, some with light honeycomb pattern, especially on pronotum; punctures throughout body usually with dark center; scutellum usually golden-tan; legs light brown; sternum and venter darker brown; eyes red to golden to silver in dried specimens, dark blotches seen in various places on some specimens, distinctive dark spots on face and vertex (Fig. 1C ).

Head. Head (Fig. 1C ) generally light brown to cream colored with dark brown markings, mouthparts dark brown. Face and vertex normally with distinctive markings consisting of pair of spots near vertex, pair of spots between top margin of eyes and vertical line along midline of face, between middle of eyes; markings can differ between individuals; 64% with dark bar and four spots, 25% with light brown bar and four spots, 10% with light brown bar and two spots, 1% with either dark or light brown bar only (see Benzie 1989, Fig. 12 for diagram showing differences). Antenna three-segmented, usually hidden from view below eye. Head size similar among Thailand specimens, head width at widest point including eyes 0.92-1.04, head width at narrowest point between eyes, 0.47-0.56, OI 49-55.

Pronotum. Base color ranging from cream to light brown, honeycombing apparent in some specimens; most have visible central lighter colored vertical band without punctures (Fig. 1B ); slight humeral bulge present laterally; posterior margin with thick sclerotized border; punctures relatively large, 0.03-0.05, with dark centers; pronotum 1.01-1.17; length 0.62-0.79; PI 61-75 (Fig. 1B ).

Wings. Complete to posterior; punctures generally in irregular rows (0.02 in diameter) (Fig. 1A ); underlying honeycomb structure sometimes present; claval suture distinct, complete; scutellum with distinct, dark punctures, more widely spaced than other punctures (Fig. 1B ); scutellum base color often golden compared to tan base of hemelytra (Fig. 1B ), although sometimes both cream colored (Fig. 1D ); yellowish-brown spot at terminal angles of corium often present as reported in original description, but not always readily apparent, posterior half rarely brownish as in original description; lateral view shows distinct dorsal horizontal shape and posterior near vertical aspects with a transition of nearly 90° (Fig. 1A, C ); scutellum slightly wider than long (Fig. 1B ), scutellum length 0.46-0.57; scutellum width 0.54-0.66; SI 104-120. Hind wings membranous, fully developed, completely concealed by hemelytra.

Legs. Typical leg measurements: prothoracic leg coxa 0.07, trochanter 0.11, femur 0.45, tibia 0.34, first tarsomere 0.02, second tarsomere 0.16,pretarsal claw 0.10; mesothoracic leg coxa 0.04, trochanter 0.18, femur 0.39, tibia 0.25, first tarsomere 0.02, second tarsomere 0.16, pretarsal claw 0.08; metathoracic leg coxa 0.04, trochanter 0.17, femur 0.47, tibia 0.53, first tarsomere 0.04, second tarsomere 0.18, third tarsomere 0.19, pretarsal claw 0.13 (see Benzie 1989, Fig. 9 for leg shapes).

Median ventral keel. Thoracic portions distinct from each other; prosternal keel rounded with posterior blunt tooth; mesothoracic keel almost rectangular; metathoracic keel irregularly shaped, somewhat in lobes, including posterior projecting small tooth, closely associated with abdominal keel, appearing almost fused; thoracic segments relatively similar between specimens. Abdominal keel variable, usually partially fused between segments, usually with four distinct teeth corresponding with first four abdominal segments. Figure of typical Thailand specimen in Fig. 2 , but also see drawing by Lundblad (1933, fig. 44H).

Characters of female. Ovipositor roughly triangular in shape, 0.25 in length, with wide side apically (gonapophysis 1) at end of rectangular shaft (gonapophysis 2) (Fig. 3 ); six distinct teeth along posterior border (apical row) plus two teeth on ventral border (ventral 1 and 2), three rows of small teeth away from apex, two primary, three secondary, and usually three tertiary, although there is variation in number of tertiary teeth; one long hair on ventral side where triangular apex of gonapophysis 1 and basal rectangle of gonapophysis 2 meet. Subgenital plate as in Fig. 4 ; wider than long; width ~ 0.67, length ~ 0.41; faintly rugose in basal one third; tufts of relatively long hairs on each side near apex; short inconspicuous hairs throughout genital plate darker v-shaped prominence in center, near apex.

Characters of male. Aedeagus bulbous and somewhat asymmetrical in the typical fashion of the family; operculum (subgenital plate) generally triangular, slightly wider than long (Fig. 5 ), width ~ 0.46, length ~ 0.41; lightly rugose throughout; with short hairs throughout.

Distribution.

Paraplea frontalis is a relatively widespread species in Thailand (Fig. 24A ) as well as other parts of Southeast Asia. This study adds the first records from Laos.

Material examined.

Hong Kong: New Territories, Yuen Long, 23 II 1971, P. & P. Spangler (5 specimens USNM). India: Pondicherry, Maindeon, 1901 (4 specimens USNM); India, Tanquebor (South India) 1951, P. S. Nathan (1 specimen USNM); Karikal, VII 1956, P. S. Nathan (5 specimens USNM). Laos: Vientaine, along Mekong River, 17°58'02.6"N, 102°36'17.6"E, 6 VIII 1997 Wolfgang G. Ulrich (1 specimens USNM). Malaysia: Penang, University of Sains Malay, 29 I 1983, H. C. Chapman (15 specimens USNM). Myanmar: Rangoon Burma (= Yangon, Myanmar) Kemmencline 10 I 1927 (2 specimens USNM); Rangoon Burma (= Yangon, Myanmar) Kemmencline 29 I 1927 (4 specimens USNM). Singapore: 1 IX 1955. Marshall Laird (8 specimens SEMC). Thailand: Ayutthaya Province: roadside pond ca. 5 km E of Ayutthaya, 2 VII 1997, L-126, R. W. Sites (2 specimens UMC). Bangkok Province: 9-10 V 1959, Manop, col., light (1 specimen USNM); Bangkok, 28 II 1971, P. & P. Spangler (10 specimens USNM). Chiang Mai Province: Amphur Hot, 18°09.930'N, 98°13.496'E, 870 m, pond, 18 V 2004, L-695 (69 specimens UMC); Chiang Mai, 10 III, 1952 m D. C. & E. B. Thurman (2 specimens SEMC). Chaiyaphum Province: Tad Tone National Park, Namtok Tad Tone, 15°58.796'N, 102°02.079'E, 210 m, 29 IV 2004, A. Vitheepradit, L-650 (1 specimens UMC); Amphur Chum Pae, 16°34.585'N, 102°01.668'E, 217 m, 3 V 2004, A. Vitheepradit, L-660, (4 specimens UMC). Chumphon Province: Amphur Sa Wi, Ban Kron, 10°14.542'N, 99°05.555'E, 6 m, 30 V 2004, L-729, Vitheepradit & Prommi (3 specimens UMC); Amphur Lamae, Ban Suan Som Boon, 09°43.311'N, 99°06.208'E, 13 m, 20 VI 2006, L-964, Vitheepradit & Prommi (1 specimen UMC). Khon Kaen Province: Amphur Chum Pae, Tumbon Noan Udom, 16°31.267'N, 102°11.323'E, 217 m, 15 IV 2009, vegetated pond, L-1039 (25 specimens UMC, 1 specimen SHSU); Khon Kaen, Khon Kaen, Bung Kaen Nakhon, 19 II 1994, William D. Shepard (1 specimen USNM); Khon Kaen City, 21 V 1954, R. E. Elbel (1 specimens USNM). Krabi Province: Amphur Mueang, Noppharat Thara Beach, 08°02.625'N, 98°48.517'E, 13 m, 8 I 2006, L-902 (8 specimens UMC). Loei Province: Amphur Nong Hin, Tumbon Nong Hin, 17°05.658'N, 101°49.193'E, 328 m, 4 V 2004, L-662, A. Vitheepradit (2 specimens UMC); Amphur Nong Hin, Ban Huay Deur, 17°05.804'N, 101°49.823'E, 316 m, 4 V 2004, L-663, A. Vitheepradit (1 specimens UMC). Mae Hong Son Province: Tam Pla Resort at Tam Pla River, 19°25'34.2"N, 97°59'16.7"E, 21 X 1997, Wolfgang G. Ulrich (1 specimen USNM). Nakhon Ratchasima Province: Nakhon Ratchasima, 60 km S of Sakaerat Experimental Station, 30-600 m, 14°30'N, 101°55'E, 2-4 III 1972, P. & P. Spangler (18 specimens USNM). Nakhon Sawan Province: Tumbon Mae Poen, 15°39.054'N, 99°28.727'E, 119 m, 23 V 2004, L-708, Vitheepradit & Prommi (11 specimens UMC); Kamphaeng San, Kasetsart University Campus, 14°00.790'N, 99°59.359'E, 15 I 2012, L-1321, among Azolla pinnata in pond, A. Vitheepradit, T. O. Prommi & R. W. Sites (1 specimen SHSU). Phetchaburi Province: Amphur Nong Ya Plong, Tumbon Nong Ya Plong, 13°09'N, 99°41'E, 69 m, 15 V 2003, L-533, Vitheepradit & Ferro (10 specimens UMC); Amphur Tha Yang, Mae Nam Phetchaburi, on HWY 3499, 12°55'N, 99°51'E, 39 m, 19 IV 2002, Vitheepradit & Kirawanich, L-354 (1 specimen). Phuket Province: mtn. stream 3 III 1968, B. A. Harrison (15 specimens). Prachuap Khiri Khan Province: Amphur Hua Hin, Ban Nong Yai Oum, 12°35'N, 99°46'E, 83 m, 16 V 2003, Vitheepradit & Ferro, L-539 (12 specimens UMC); Amphur Thap Sakae, Ban Huay Yang, 11°36'N, 99°38'E, 25 m, 18 V 2003, Vitheepradit & Ferro, L-543 (2 specimens UMC). Sakon Nakhon Province: Sakonnakhora (sic) city reservoir, 3 II 1952, M. E. Griffith (16 specimens SEMC). Sara Buri Province: Amphur Sao Hal (2.7 km west), 14°33'N, 100°49'E, 11 III 1971, P. & P. Spangler (1 specimen USNM). Songkhla Province: Amphur Rataphum, Tumbon Kampangphet, 07°08.030'N, 100°18.437'E, 30 m, 2 VI 2004, Vitheepradit & Prommi, L-732 (38 specimens UMC, 1 specimen SHSU); Amphur Hat Yai, Prince of Songkla University, pond near reservoir, 07°00'N, 100°30'E, 58 m, 4 V 2002, Vitheepradit & Kirawanich, L-391 (1 specimen UMC). Surat Thani Province: Amphur Phuphin, Tumbon Khao Kwai, 09°03.773'N, 99°14.521'E, 17 m, 16 VI 2004, Sites, Vitheepradit, & Prommi, L-771 (2 specimens SHSU); Amphur Ban Na, Ban Huay Harng, 08°50.925'N, 99°18.215'E, 24 m, pond, 20 VI 2004, Vitheepradit & Prommi, L-781 (1 specimen, UMC); Amphur Ban Na, Ban Tha Rau Tai, 08°56.567'N, 99°15.130'E, 4 m, 20 VI 2004, L-782, Vitheepradit & Prommi (1 specimen SHSU); Amphur Ban Na San, Ban Poo Pea, 08°40.490'N, 99°20.092'E, 4 m, 19 VI 2006, L-962, Vitheepradit & Prommi (36 specimens UMC, 1 specimen SHSU). Tak Province: Amphur Meung, Tumbon Nhong Bua Tai, 16°49'N, 99°07'E, 106 m, 9 V 2003, L-514 (50 specimens UMC, 1 specimen SHSU). Trang Province: Amphur Sikao, pond at Chao Mai Beach, 07°26.842'N, 99°20.647'E, 3 m, 9 I 2003, Vitheepradit & Prommi, L-907 (28 specimens UMC); Prince of Songkla University, 7°31'N, 99°35'E, 55 m, 7 VI 2003, CMU and PSU teams, L-597 (13 specimens UMC, 1 specimen SHSU). Uthai Thani Province: Amphur Ban Rai, Tumbon Kang Roong, 15°14.121'N, 99°41.002'E, 69 m, 24 V 2004, L-712, Vitheepradit & Prommi, (3 specimens UMC); Amphur Mueang, Tumbon Nam Serm, 15°20.886'N, 100°02.120'E, 20 m, 24 V 2004, L-713, Vitheepradit & Prommi (1 specimen UMC). Northeast Thailand, 15 I 1953, M. E. Griffith (90 specimens SEMC, 5 specimens SHSU).

Discussion.

Because of the wide geographic distribution and variable characters, it is possible that what has previously been considered to be P. frontalis may include more than one species. Previously, it has not been possible to differentiate between species variation and species boundaries. However, after viewing hundreds of specimens, it appears that there are some reliable characters as long as there is a series of specimens in the sample to account for the variation. Lundblad (1933) noted that this is a species with variable characters, which is supported by the findings of this study. If a single specimen is used for identification, there may be some uncertainty in obtaining an accurate identification. The most apparent diagnostic character of P. frontalis is the facial marking found in most specimens, consisting of five dark marks, one vertical stripe on the center of the face and two pairs of horizontal stripes (Fig. 1C ). Nearly 90% of specimens examined had these markings (although with variation in how dark these markings appear); thus, with a series of specimens, the species as now defined is readily identified. The current data did not include the type specimens (because they were never designated); however, they did match this diagnostic characteristic given in the original description. Paraplea brunni (Kirkaldy) and P. halei (Lundblad) also commonly have facial markings but they are usually restricted to the center vertical stripe and are not known to have the full component in the pattern shown in Fig. 1C . The scutellum in most specimens of P. frontalis is a contrasting lighter color and is often golden-orange. The keel of these specimens is also usually diagnostic, having well-defined teeth on the abdominal segments that are relatively longer than in other species, but there is variation in this character. Some specimens have smaller teeth, which could have resulted from wear, and the shape of these teeth can vary from being relatively straight to curved. The drawings of the keel by Lundblad (1933) of specimens from Indonesia had smaller teeth on the abdominal keel than did the majority of those examined in this study, but without examining the Indonesian specimens, it is uncertain if this is typical of specimens from these islands. As with most species of Pleidae , the ovipositor and subgenital plates of both sexes are diagnostic of the species. The ovipositor of P. frontalis most commonly has the teeth as shown in Fig. 3 , but some specimens appear to be lacking inner teeth. This could be slight intraspecific variation or possibly interspecific differences if P. frontalis proves to be a species complex.

Figures

Figure 1. Paraplea frontalis specimens from Thailand. Male with most typical coloration in (A) lateral view, (B) dorsal view, and (C) frontal view. (D) Female showing an alternatively colored form in lateral view.

Figure 2. Ventral keel of Paraplea frontalis, anterior region to the left, ventral to the top.

Figure 3. Ovipositor of Paraplea frontalis with gonapophysis 1 to right and gonapophysis 2 to left. Scale bar: 0.1 mm.

Figure 9. Ovipositor of Paraplea lateromaculata sp. nov. Scale bar: 0.05 mm.

Figure 12. Paraplea liturata specimens from Thailand. A female in lateral view with typical coloration, B dorsal view in that shows dark banding and honeycombing. C frontal view of specimen in B. D mele showing an alternatively colored form in lateral view.

Figure 24. Distribution records in Thailand of A Paraplea frontalis B P. lateromaculata sp. nov., C P. liturata D P. melanodera sp. nov.

Figures 4 - 5. Genital plates of Paraplea frontalis. 4 female, 5 mele. Scale bar: 0.2 mm.