Key to species of Hemerodromia occurring in Thailand

In using the key it is important to recognise that while colouration provides useful characters to discriminate certain species, it can be variable. For example, species with thorax entirely black may appear brownish or reddish brown in teneral specimens and intraspecific variation in the strength of colour patterns sometimes occurs in species with a predominantly yellow thorax. The user is urged to confirm all determinations by reference to the detailed descriptions and using characters of the terminalia of males. In many cases, females are extremely difficult or impossible to identify with confidence. Caution is also needed as there are certainly other species occurring in Thailand that remain undescribed.

1 Wing with R2+3 terminating in R4 and strong black mark on membrane about R4 (Figs 3, 4). Head with posterodorsal margin strongly quadrate in lateral view. Upper occiput shallowly concave (Fig. 5). Anterodorsal margin of thorax very distinctly quadrate in lateral view...................................................... Hemerodromia anomala sp. nov.

- Wing with R2+3 terminating in C, membrane about R4 hyaline (Figs 1, 6–8). Head with posterodorsal margin more rounded in lateral view (usually distinctly so). Upper occiput convex, at most somewhat flattened. Anterodorsal margin of thorax usually narrowing gradually towards front viewed in profile (Figs 6–8)................................................ 2

2 Wing (Figs 1, 7) with M1+2 fork present (vein M2 present); halter whitish, blackish or dusky (usually without marked contrast between anterior and posterior faces of knob). T1 with 1 or 2 rows of minute denticles ventrally (rows often subequal in strength)........................................................................................... 4

- Wing (Fig. 6) with M1+2 fork absent (vein M2 absent); halter with anterior face of knob black, posterior face pale (division between the two usually very distinct). T1 with a single row of minute denticles ventrally........................... 3

3 Male terminalia with cercus strongly curved dorsally on distal part (Fig. 18); surstylus very broad, its tip strongly reflexed dorsally.................................................................... Hemerodromia attenuata sp. nov.

- Male terminalia with cercus elongate, linear on distal part (Fig. 29); surstylus with tip slightly spatulate........................................................................................... Hemerodromia deminuta sp. nov.

4 Ground colour of anepisternum and katepisternum yellow or brownish yellow, sometimes heavily suffused brown or blackish but never distinctly black (underlying ground colour always yellowish) (Figs 1, 7, 8)............................... 5

- Ground colour of anepisternum and katepisternum black or brown (underlying ground colour always black or brownish, sometimes variably suffused reddish, never distinctly yellow) (Figs 3, 5, 6)......................................... 20

5 Halter with knob black or at least distinctly darkened; wing distinctly and evenly dark greyish on distal 0.9...................................................................... Hemerodromia furcata Grootaert, Yang & Saigusa, 2000

- Halter with knob whitish, yellowish or pale brownish yellow; wing usually less darkened or almost hyaline on distal 0.9 or with strong darkening restricted to area around apices of basal cells............................................. 6

6 Scutum entirely yellow, at most a faint narrow median dark area in prescutellar area and/or more or less distinct darker lateral stripes on posterior 0.5 (males only)..................................................................... 11

- Scutum entirely brownish or black or with dark markings otherwise and more extensive............................. 7

7 Scutum with anterior 0.5 clear yellow, posterior 0.5 blackish (Fig. 8)........................................................................................................................ Hemerodromia songsee sp. nov.

- Scutum entirely brownish or black or with dark markings otherwise............................................ 8

8 Scutum entirely black or dark brown, even laterally, at most postpronotal area somewhat yellowish (Fig. 1); laterotergite and meron black, hardly paler than scutum.............................. Hemerodromia flaviventris Yang & Yang, 1991

- Scutum yellowish laterally, even if narrowly so, postpronotal area often yellow; laterotergite yellow or sometimes suffused brownish black but never uniformly and intensely black..................................................... 9

9 Scutum narrowly yellowish laterally (Fig. 7), postpronotal area usually yellowish; pleura yellowish, often partly suffused brownish. Cell bm+dm long, ending distinctly beyond level of R1................... Hemerodromia systoechon sp. nov.

- Scutum with broad lateral yellow markings more extensive, especially anteriorly; often with a more or less well defined dark median stripe, narrowing anteriorly. Cell bm+dm short ending at level of R1, or if ending distinctly beyond end of R1 then a short stub of CuA2 present............................................................................. 10

10 Scutellum entirely black; scutum with median dark stripe broad; prothoracic ‘collar’ broadly black dorsally. Wing with a short stub of vein CuA2 present; length of C between ends of R2+3 and R4 long, ~1.8X long as R4; cell bm+dm long, ending distinctly beyond level of R1. Male cercus with complex process situated along inner face with convoluted tip bearing 4 blunt spines orientated internally (Fig. 52).................................................... Hemerodromia isochita sp. nov.

- Scutellum yellow or yellowish, at least posteriorly; scutum with dark median stripe narrower; prothoracic ‘collar’ with dorsal surface yellow, black only very narrowly at middle. Wing with no trace of vein CuA2; length of C between ends of R2+3 and R4 short, ~1.0–1.2X long as R4; cell bm+dm short, ending at about level of R1. Male cercus (Figs 9, 10) elongate, with only short small strong setae on inner face apically..................... Hemerodromia acutata Grootaert, Yang & Saigusa, 2000

11 Cell bm+dm long, ending beyond tip of R1; sct present, distinct if small (if bm+dm short and sct present see Hemerodromia namtokhinpoon sp. nov.)............................................................................. 12

- Cell bm+dm short, ending near tip of R1; sct absent, at most a few fine hairs on disc.............................. 17

12 F1 with ~3 spines of pv row between 0.2 and 0.7 from base obviously longer than limb is deep................................................................................................. Hemerodromia alphalutea sp. nov.

- F1 with spines of pv row obviously shorter than limb is deep (excepting 1–2 near base longer)...................... 13

13 Scutum with more or less distinct dark lateral stripes posteriorly. Epandrium with small quadrate process apically bearing close ciliation of fine hairs (Fig. 20)................................................ Hemerodromia betalutea sp. nov.

- Scutum plain yellow, any dark markings very obscure. Male terminalia otherwise................................ 14

14 Mediotergite clear yellow (if somewhat vaguely obscured brownish see Hemerodromia deltalutea sp. nov.)............ 15

- Mediotergite black or brownish, sometimes with posterior or lateral margins yellow.............................. 16

15 Wing membrane brownish; veins brownish yellow, rather darker about junction of R1 with C, base of R2+3 and R4+5 and cell bm+dm posteriorly. Abdomen with tergite 2 blackish (as are 3–5). Hypandrium and epandrium clear yellow....................................................................................... Hemerodromia epsilutea sp. nov.

- Wing membrane yellowish; veins yellow, not obviously darker about basal forks. Abdomen with tergite 2 yellow (sometimes narrowly darker medially) and 3–5 blackish. Hypandrium and epandrium black.......... Hemerodromia etalutea sp. nov.

16 Epandrium very strongly concave on dorsal margin (Fig. 26). Tergites 2–6 mostly blackish. R4+5 fork distal to M1+2 fork by same or slightly greater than length of R4....................................... Hemerodromia deltalutea sp. nov.

- Epandrium convex on dorsal margin (Fig. 48). Tergites 2–5 mostly blackish; R4+5 fork distal to M1+2 fork by less than length of R4.................................................................... Hemerodromia gammalutea sp. nov.

17 Sct absent; posterior margin of scutum with clearly defined black ‘scutoscutellar eye’ marking; prothoracic collar dorsally with narrow dark median mark. Wing with veins blackish, membrane browner, both only slightly darkened at about level of cell bm+dm. Epandrium broad, if elongate then lacking very strong apical bristle.................................... 18

- Sct present; posterior margin of scutum entirely yellow, lacking dark ‘scutoscutellar eye’; prothoracic collar dorsally entirely yellow. Wing veins yellowish grey, membrane yellowish brown, both darkened conspicuously at about level of cell bm+dm. Epandrium very elongate with strong apical bristle........................... Hemerodromia namtokhinpoon sp. nov.

18 Anterior spiracle narrowly (usually strongly) emarginated above with small linear diagonal black mark. Epandrium narrowly elongate in lateral view (Fig. 71)............................................... Hemerodromia zetalutea sp. nov.

- Anterior spiracle lacking strong linear diagonal mark, at most with a small dark spot present. Epandrium subovate or subrectangular in lateral view (Figs 14, 55)..................................................................... 19

19 Epandrium truncate apically; narrow process (lower lobe of surstylus?) emerging beyond tip of epandrium below surstylus bent at 90° with 2 small leaf-shaped setae apically (Fig 14)....................... Hemerodromia anisoserrata sp. nov.

- Epandrium less truncate apically (Fig. 55); narrow process (lower lobe of surstylus?) emerging beyond tip of epandrium below surstylus more or less linear with 2 large leaf-shaped setae apically (Fig. 57)............ Hemerodromia ocellata sp. nov.

20 Head with 4–5 pairs of distinct vtl distinguishable from other fine setulae on vertex and upper occiput. Male terminalia (Figs 23–25) small and compact; cercus rather broad and simple in lateral view............. Hemerodromia conspecta sp. nov.

- Head with 1–2 pairs of indistinct vtl, not much stronger than other fine setulae on vertex and upper occiput. Male terminalia larger; cercus narrowed in lateral view or if broad, with complex apical processes................................ 21

21 Male cercus broad in lateral view with prominent apical downwardly directed process (Figs 32, 33)............................................................................................... Hemerodromia demissa sp. nov.

- Male cercus elongate in lateral view (Figs 46, 58, 60, 68), sometimes with shorter dorsal lobe at about 0.5 from base (Fig. 46).................................................................................................. 22

22 Male cercus moderately elongate in lateral view (Fig. 46), extending beyond tip of epandrium, a shorter dorsal lobe originating ~0.5 from base (sometimes twisted internally and inconspicuous in lateral view); surstylus large and conspicuous, broadly Tshaped apically (Fig 46)............................................... Hemerodromia fusca Yang & Yang, 1986

- Male cercus long and narrow in lateral view (Figs 58, 60, 68), without dorsal lobe; surstylus shorter or if elongate then a different shape apically................................................................................... 23

23 Epandrium rather narrow in lateral view, apically pointed (Figs 58, 59); surstylus small, narrow, apically spatulate, incurved distally..................................................................... Hemerodromia oriens sp. nov.

- Epandrium broader, bluntly pointed ovoid or subcircular in lateral view; surstylus otherwise........................ 24

24 Two processes projecting beyond tip of epandrium (Fig. 68), upper one (surstylus) conspicuously inflated and broadly Lshaped apically; lower process elongate hook-shaped apically (Fig. 70).... Hemerodromia yunnanensis Yang & Yang, 1988

- Two processes projecting beyond tip of epandrium (Fig. 60); upper one narrow, apically spatulate with minute peg-like tubercles apically on inner face (Fig. 62); lower one rather digitiform, with dense brush of fine almost coalescent hairs apically................................................................... Hemerodromia phahompokensis sp. nov.