Pilophorini, Douglas & Scott, 1865

Yasunaga, Tomohide, Duwal, Ram Keshari & Nakatani, Yukinobu, 2020, Reclassification of the plant bug genus Pilophorus in Japan and key to the genera and species of Japanese Pilophorini (Hemiptera: Heteroptera: Miridae Phylinae), Zootaxa 4942 (1), pp. 1-40 : 4-6

Key to genera and species of Pilophorini in Japan

1. Body ovoid, elongate-oval (rather conventional mirid shape) or rounded, sometimes disk-like or tortoise-shaped; silvery scalelike setae on hemelytron (if any) not clustered, sparsely or uniformly distributed, or forming broad band at middle (as in Pherolepis fasciatus and Pilophorus tagoi , cf. Fig. 6C, H)..................................................... 2

– Body elongate, more or less myrmecomorphic (or if body oblong-ovoid and not particularly antlike then hemelytron always with a continuous median band of silvery scale-like setae as in Fig. 6A); silvery scale-like setae on hemelytron linearly and/or roundly clustered; silvery setae on scutellum partly clustered or roundly bundled....................... Pilophorus – 11

2. Antennal segment II remarkably enlarged, terete or boxlike................................... Druthmalus miyamotoi

– Antennal segment II not strongly enlarged or almost linear, or slightly incrassate towards apex (apical part less than twice as thick as base)........................................................................................ 3

3. Pronotum darkened, shiny, only with sparsely distributed silvery setae........................................... 4

– Pronotum either less shining (sometimes matte) or more or less (sometimes densely) covered with silvery scale-like setae.. 7

4. Total body length <2.8 mm; antennal segment II somewhat clavate (apical part about twice as thick as base); hemelytron matte, brick-red or reddish brown; restricted to a Japanese cedar, Cryptomeria japonica ....................... Pilophorus tagoi

– Total body length Ẑ 3.1 mm; antennal segment II almost linear; hemelytron shiny brown to fuscous; associated with deciduous broadleaf trees............................................................................ Pherolepis – 5

5. Head glabrous; antennal segment II longer than head width across eyes; scale-like setae on hemelytra forming a broad band at middle..................................................................................... Ph. fasciatus

– Head more or less setose; antennal segment II about as long as or shorter than head width across eyes; scale-like setae of hemelytra sparsely and uniformly distributed............................................................... 6

6. Pronotum with sparsely distributed, short, simple setae and anteriorly with silvery setae; all femora somber yellowish brown.......................................................................................... Ph. hizenicus

– Pronotum with uniformly distributed, long, simple setae, lacking silvery setae; all femora reddish brown.... Ph. kiritshenkoi

7. Body short-ovoid or tortoise-shaped; thoracic pleurites with anterior and posterior glands (cf. Yasunaga & Duwal, 2019); tibia with clear dark annulations, or rings.......................................................... Hypseloecus – 8

– Body ovoid or elongate oval; thoracic pleurites without such glandular structure; tibia lacking dark annulation........... 9

8. Base and apical 1/4 of antennal segment II darkened; known from cold temperate zone in mountain areas of Honshu................................................................................................ H. nakagawai

– Antennal segment II with pale basal half and darkened apical half; thermophilic species inhabiting Yaeyama Islands of Ryukyus.................................................................................. H. takahashii

9. Dorsal surface matte, weakly shining; antennal segment II obviously thicker than labial segments II–IV; pretarsus with setiform parempodia; arboreal species associated only with Ficus trees.................................. Lasiolabops cirratus

– Dorsal surface more or less shining; antennal segment II about as thick as labial segments II–IV; parempodia fleshy; inhabiting graminoid grasses or sedges................................................................ Sthenaridea – 10

10. Dorsum generally reddish brown; profemur uniformly creamy yellow.................................... S. rufescens

– Dorsum dark brown, sometimes partly yellow, not tinged with red; at least basal half of profemur reddish brown or dark brown.................................................................................... S. piceonigra

11. Pronotum and hemelytron with uniformly distributed, short setae, mixed with long, stiff, upright setae (easily confirmed in lateral view) (cf. Figs 5F, 17B, 18J)...................................................................... 12

– Pronotum and/or hemelytron almost glabrous, or only with uniformly or sparsely distributed, short, reclining or semierect setae, lacking distinct upright vestiture........................................................................ 13

12. Antennal segment II <1.4 mm, usually shorter than mesotibia; dark upright setae on hemelytra sparsely distributed........................................................................................... P. setulosellus n. sp.

– Antennal segment II> 1.5 mm, as long as or longer than mesotibia; dark upright setae on hemelytra almost uniformly distributed................................................................................... P. setulosus

13. Hemelytra with almost continuous and nearly straight median transverse stripe of silvery scale-like setae (across exocorium, corium and clavus as in Figs 1C, 2A, C, E, 6 A–B).......................................................... 14

– Hemelytral scale-like setae scattered, partly clustered; median stripe of scale-like setae (if present) partly notched, zigzag, arched, slipped or interrupted (e.g., Figs 1A, 5A, D)......................................................... 19

14. Antennal segment II clavate, with its apical part more than 1.7 times as thick as base; inhabiting conifers in temperate and/or cold temperate zones................................................................................. 15

– Antennal segment II almost linear or weakly incrassate towards apex (its apical part less than 1.5 times as thick as base); inhabiting broadleaf trees or sometimes herbs (assumed conifer inhabitant, P. nakatanii ( Fig. 2E) known only from subtropical Ryukyu Islands)..................................................................................... 16

15. Apical part of antennal segment II 1.2–1.3 times as thick as metatibia; pronotum somewhat matte, less shining; each angle of scutellum with clustered scale-like setae ( Fig. 6A).................................................. P. miyamotoi

– Antennal segment II remarkably clavate, with its apical part nearly twice as thick as metatibia; pronotum shining; scutellum with scattered silvery scale-like setae from lateral margin to apex ( Fig. 6B)............................. P. validicornis

16. Body largest among Japanese congeners, more than 4.0 mm (³)/ 4.6 mm (♀) in total length; hemelytra almost uniformly black or blackish brown; pronotal width Ẑ 1.34 mm; anterior inner part of cuneus with a circularly clustered scale-like setae ( Fig. 1C)........................................................................................... P. niger

– Body less than 3.9 mm (³)/ 4.4 mm (♀) in total length; hemelytra, at least anterior to median stripe of scale-like setae, brown or reddish brown; pronotal width <1.3 mm; cuneal scale-like setae scattered or forming an irregular band.............. 17

17. Antennal segment II almost uniformly darkened; pronotum polished, very shiny, with sparsely distributed, short setae ( Fig. 2E); thermophilic, known only from Ryukyu Islands..................................................... P. nakatanii

– More than basal half of antennal segment II yellowish or reddish brown; pronotum somewhat matte, with uniformly distributed, short setae; inhabiting temperate or cold temperate climate zone, north of Kyushu (or N31° latitude).................. 18

18. Vertex in both sexes 0.47–0.49 times as wide as head including eyes; antennal segment II slightly clavate; metatibia somewhat curved ( Fig. 2 A–B)............................................................................ P. erraticus

– Vertex narrower, 0.38–0.44 (male)/0.43–0.45 (female) times as wide as head including eyes; antennal segment II and metatibia almost linear ( Fig. 2 C–D)................................................................. P. pseudoperplexus

19. Small-sized species, with total body length ± 3.0 mm........................................................ 20

– Body larger, more than 3.4 mm in total length.............................................................. 23

20. Dorsum (except for silvery setae) uniformly dark brown to fuscous............................................. 21

– At least hemelytra brown or reddish brown................................................................ 22

21. HCR larger (0.66–0.75 in male/ 0.66–0.74 in female); in male, antennal segment II usually greater than twice as long as III and left paramere smaller, weakly expanded left-laterally ( Figs 9L, 15 N–O); in female, vertex narrower (± 0.39 mm; vertex/head width across eyes = 0.50) and interramal lobe with 2–3 rows of spines along margin ( Fig. 16 K–L).............. P. typicus

– HCR smaller (0.62–0.67 in male/ 0.62–0.66 in female); in male, antennal segment II usually twice as long as III and left paramere more strongly expanded left-laterally, spatula-shaped ( Figs 9I, 15G); in female, vertex wider (Ẑ 0.40 mm; vertex/head width = 0.53–0.57) and interramal lobe with 4–5 rows of spines along margin ( Fig. 16 N–O)............... P. hyotan n. sp.

22. Head width across eyes about 1.2 times as long as its height, narrower than pronotal width; HCR> 0.81 ( Fig. 1B); northern Honshu.................................................................................... P. maeharai

– Head width across eyes less than 1.1 times as long as its height, almost equal to pronotal width; HCR <0.77 ( Fig. 1F); Ryukyus (Amami-Oshima Is.) and Taiwan.................................................................. P. pullulus

23. Pronotum weakly shining, with uniformly distributed, brown, short setae; usually associated with herbaceous vegetation ( Artemisia spp.) or shrubs ( Lespedeza spp.)................................................................ 24

– Pronotum polished, only with sparsely distributed, short setae or almost glabrous; arboreal species restricted to Fagaceae oaks .................................................................................................. 25

24. Antennal segment II usually longer than maximum width of hemelytra; median stripe of scale-like setae on corium almost continuous across M-vein (media) ( Fig. 5 C–D)...................................................... P. okamotoi

– Antennal segment II about as long as or shorter than maximum width of hemelytra; median stripe of scale-like setae on corium shifted or interrupted at M-vein( Fig. 5 A–B)................................................ P. satoyamanus n. sp.

25. Antennal segment II as long as or slightly longer than basal width of pronotum; apex of scutellum with silvery scale-like setae; cuneus lacking scale-like setae ( Fig. 2F)............................................................ P. lucidus

– Antennal segment II shorter than pronotal width; apex of scutellum without silvery scale-like setae; anterior inner corner of cuneus with scale-like setae ( Fig. 1A)................................................................ P. choii