Fingulus angkorensis Yasunaga & Yamada

Yasunaga, Tomohide, Yamada, Kazutaka, Duangthisan, Jomsurang & Artchawakom, Taksin, 2016, Review of the plant bug genus Fingulus Distant in Indochina (Hemiptera: Heteroptera: Miridae: Deraeocorini), with descriptions of two new species, Zootaxa 4154 (5), pp. 581-588 : 583-584

Fingulus angkorensis Yasunaga & Yamada , n. sp.

( Figs. 1 , 3 A–C, 4A–B)

Diagnosis. Distinguished from any other congeners by a combination of the following characters: punctate pronotal collar; uniformly pale antennal segments II–IV; dark ostiolar peritreme; pale legs with darkened apex of each femur and base of each tibia. Most similar to F. porrectus (Bergroth) known from Hong Kong and India in general shape of body; distinguished by its uniformly fuscous dorsum; dark antennal segment I; shorter labium not exceeding apex of procoxa; darkened apices of femora and bases of tibiae; and endosoma with an elongate, slender spiculum and a sword-like lobal sclerite.

Description. Body generally dark brown, elongate in form; dorsal surface shining, with rather shallow and roughly arranged punctures. Head slightly shorter than or almost equal to width across eyes in dorsal view; vertex narrowly carinate at base; tylus vertically slanted; neck moderate, with postocular region a little constricted. Antenna uniformly pale brown except for shiny dark brown segment I. Labium shiny brown, short, not exceeding apex of procoxa; apex of segment IV narrowly infuscate. Pronotum including collar punctate; calli oily shiny, almost smooth; scutellum nearly flat; pleura fuscous; propleuron punctate; ostiolar peritreme tinged with gray, matte, not contrasting with surrounding areas. Hemelytron nearly parallel-sided, rather roughly punctate; cuneus impunctate; membrane pale brown, semitransparent, basally suffused with fuscous to level of apices of areolar cells. Coxa and leg pale brown; each coxa more or less tinged with brown; more than apical 1/3 of each femur and base of each tibia dark brown; extreme apex of protibia fuscous. Abdomen shiny fuscous. Male genitalia: Left paramere with roundly developed sensory lobe; hypophysis with weak, flattened apical process ( Fig. 4 A). Endosoma ( Fig. 4 B) with a slender, long spiculum and a sword-like lobal sclerite.

Measurements. ♂ / ♀: Total body length 3.6−3.8/ 4.1−4.5; length of head 0.56−0.62/ 0.61−0.63; width of head across eyes 0.63−0.64/ 0.61−0.62; width of vertex 0.09−0.12/ 0.12−0.13; lengths of antennal segments I −IV 0.41−0.43, 1.45−1.47, 0.91−0.94, 0.60−0.62/ 0.46−0.49, 1.46−1.60, 0.89−1.00, 0.56−0.59; length of labium 1.22−1.33/ 1.34−1.35; mesal length of pronotum including collar 0.96−0.98/ 0.85−1.03; basal width of pronotum 1.09−1.12/ 1.28−1.33; maximum width across hemelytron 1.12−1.17/ 1.34−1.49; and length of metafemur, tibia and tarsus 1.28−1.30, 1.82−1.85, 0.28−0.30/ 1.40−1.47, 1.82−1.90, 0.30−0.32.

Etymology. Named after the type locality, the Angkorian World Heritage site.

Biology. Adults of this new species were found on leaves ( Fig. 1 A) of Ficus microcarpa L.f. ( Moraceae ), and some of them in leaf curl galls ( Fig. 1 B) induced by a thrips, Gynaikothrips sp. ( Thysanoptera : Tubulifera), during recent observations at a college campus in Siem Reap, Cambodia. From the galls on one tree of Ficus microcarpa , both adults and immature forms of (undescribed) Montandoniola sp. ( Anthocoridae : Oriini ) ( Fig. 1 C, D) and a few adults of Cardiastethus exiguus Poppius ( Anthocoridae : Cardiastethini ) ( Fig. 1 D) were found. The new mirid, F. angkorensis , and these two anthocorids presumably predate on the thrips. As pointed out by Nakatani et al. (2000) and Yasunaga et al. (2001), the nymphs of some Fingulus members are presumed to mimic their hosts (thrips) (cf. Fig. 2 D). This phenomenon suggests close relationships between Fingulus species and the thrips, as implied by Yasunag a et al. (2015). In Japan Fingulus longicornis Miyamoto and Montandoniola thripodes Bergroth are known to co-occur in the gall of Ficus microcarpa made by their assumed prey, Gynaikothrips ficorum (Marchal) ( Yamada et al., 2010; Yasunaga et al., 2001; 2015).

Holotype: ♂, CAMBODIA: Siem Reap, PTTC [Provincial Teacher Training College] Campus , 3km S of Angkor Wat, 13º22'51.50" N 103º51'51.30" E, on Ficus microcarpa , 31 Mar 2014, T. Yasunaga ( AMNH _PBI 00380424) ( DOAT).

Paratypes. CAMBODIA: Same data as for holotype, 2♂ (00380425−00380426), 4♀ ( AMNH, TYCN) ; same data except for date 4 Apr 2014, 1♂ 1♀ ( TYCN) . THAILAND: Nakhon Nayok, Sarika , N14º17'16.35" E101º17'22.77", on Ficus microcarpa , 16 Dec 2011, T. Yasunaga, 2♀ (00380427−00380428) ( TYCN) ; Nakhon Ratchasima, Wang Nam Khieo, Sakaerat Environmental Research Station ( SERS), 24 Dec 2012, T. Yasunaga, B. Shishido, 1♀ (00380429) ( TYCN) .

Figures

FIGURE 1. Habitat and habitus images for Fingulus angkorensis, and minute pirate bugs, Montandoniola sp. and Cardiastethus exiguus Poppius associated with leaf-curl gall produced by Gynaikothrips sp. (Thysanoptera: Tubulifera) on Ficus microcarpa in Siem Reap, Cambodia. A. Leaf curl-galls (1) and F. angkorensis, adult female. B. F. angkorensis, adult male staying with gall-making thrips in a gall. C. F. angkorensis (right) and Montandoniola sp., adult females. D. Adults of Montandoniola sp. (upper right), Cardiastethus exiguus (upper left) and Gynaikothrips sp. E. F. angkorensis, female. F. Same, male, left lateral view.

FIGURE 2. Habitus images of Fingulus spp. (A − D) and Angerianus spp. (E − F) A − B. Fingulus rubricatus, holotype male. C. F. collaris Miyamoto, female adult from Ishigaki Island, Ryukyus, Japan. D. Same, final instar nymph from Iriomote Island, Ryukyus. E. Angerianus fractus Distant, male from SERS. F. A. maurus Distant, female from SERS. Images C & D courtesy of Mr. M. Takai.

FIGURE 3. Dorsal (A − B) and ventral (C − D) habitae of Fingulus spp. A. F. angkorensis, male. B − C. Same, female. D. F. rubricatus, holotype male.

FIGURE 4. Male genitalia of Fingulus angkorensis (A − B) and F. rubricatus (C), named on the figures.