Hebridosimulium, Grenier & Rageau, 1961

Craig, Douglas A., Currie, Douglas C., Hunter, Fiona F. & Spironello, Mike, 2006, A taxonomic revision of the southwestern Pacific subgenus Hebridosimulium (Diptera: Simuliidae: Simulium), Zootaxa 1380 (1), pp. 1-90 : 15-16

Key to later instar larvae of Hebridosimulium

Larvae of S. lucyae and S. anatolicum are unknown.

1. Posterior abdomen steatopygous (expanded posterolaterally and posteroventrally) ( Figs. 11h , 12b ), circlet of hooks directed posteriorly, more than 5,000 hooks ( Fig. 22b ) ........................................................................................................................ 2

- Posterior abdomen callipygous (not markedly expanded) ( Figs. 11a , 12a ), circlet of hooks directed more ventrally, less than 4,000 hooks ( Fig. 22a ) ....................... 3

2 (1). Head darkly pigmented … ( adsonense subgroup. Figs. 11m, n ; 14e, f ) ............... 7

- Head pattern with anterior apotome pale or lightly pigmented ( Fig. 13 ) ............... 8

3 (1). Abdomen with dorsolateral tubercles ( tuberculum subgroup. Figs. 11b–e ) .......... 4

- Abdomen lacking dorsolateral tubercles ( Fig. 11a ) ........................... S. callipygium

4 (3). Head lightly pigmented overall, posteromedial head spots not marked ( Fig. 13b ). .................................................................................................................... S. banksi

- Head pale anteriorly, pigmented posteriorly, head spots more distinct ................. 5

5 (4). Posteromedial head spots in distinct Eiffel Tower configuration, lateral head spots distinct ( Fig. 15a . Tanna), or less so (Erromango) .............................. S. johnfrumi

- Head spot not as above, posterior apotome pigmented, posterolateral head spots pale ( Figs. 13 , g, h) ................................................................................................. 6

6 (5). Abdomen markedly pigmented and banded. Malekula ( Fig. 11d ). S. pankumuense

- Abdomen paler. Efate ( Fig. 11e )......................................................... S. tuberculum

7 (2). Ecdysial lines markedly pale and straight, posterior inflexion sharper (Santo) ( Fig. 14e ) ...................................................................................................... S. adsonense

- Ecdysial lines markedly pale but curved, posterior inflexion more rounded (Malekula) ( Fig. 14f )............................................................................................. S. spiroi

8 (2). Head pale with well-developed posteromedial head spots in Eiffel Tower configuration ....................................................................................................................... 9

- Head pale without distinct head spots, or more evenly, heavily pigmented......... 12

9 (8). Lacking posterolateral pigmentation on apotome ( Fig. 13f ) ......................... S. jolyi

- With posterolateral pigmentation on apotome ( Figs. 14a, b )................................ 10

10 (9). Head evenly light brown, posterolateral pigmentation not markedly developed ( Fig. 14a ) ......................................................................................... S. steatopygium

- Head markedly pale with posterolateral pigmentation distinct ( Figs. 14b, d )...... 11

11 (10). Posteromedial head spots in Eiffel Tower configuration, posterior edge of apotome markedly emarginate ( Fig. 14d ) ................................................. S. undulatum

- Lacking Eiffel Tower configuration, posterior edge of apotome not emarginate ( Fig. 14b ) ...................................................................................... S. subparadisium

12 (8). Head evenly pigmented, but anterior apotome pale, muscle scars prominent...... 13

- Head evenly pale, muscle scars not markedly developed ( Fig. 14c ). Distinct dark line and spot above lateral stemmata ( Fig. 15c ) .............................. S. supercilium .

13 (12). Anterior genae pale ( Figs. 13g , 15b ; Fiji only) ................................... S. laciniatum

- Anterior genae heavily pigmented ( Fig. 13h ) .................................... S. paradisium

Figures

FIGURE 11. Left lateral views of Hebridosimulium species larvae. Last-instar larvae, except l & n, which are penultimate. Arrowheads indicate dorsal tubercles. Scale bar = 1.0 mm.

FIGURE 12. Posterior abdomens of larvae of Hebridosimulium. Dorsal views. Scale bar = 0.5 mm.

FIGURE 13. Dorsal views of larval heads of Hebridosimulium species. a–e. callipygium species group, f–h. part of steatopygium species group. Last instars, except f & h, which are penultimate instars. Arrows (b & e) indicate anterior palatal bar. Scale bar = 0.2 mm.

FIGURE 14. Dorsal views of larval heads of Hebridosimulium species. steatopygium species group. Last instars, except d & f, which are penultimate instars. Scale bar = 0.2 mm.

FIGURE 15. Left lateral views of larval heads of Hebridosimulium species. Left labral fan removed for clarity. Last instars except c, which is penultimate. Scale bar = 0.2 mm.

FIGURE 22. Anal sclerite and circlet of hooks of larvae of Hebridosimulium species. Last instar. Ca. 2800 and 7300 hooks, respectively. Scale bar = 0.2 mm.