Limbodessus, Guignot, 1939

Michat, Mariano C., Alarie, Yves & Watts, Chris H. S., 2012, 3584, Zootaxa 3584 (1), pp. 1-110 : 98-100

Key to larvae of Limbodessus

The key presented here was prepared to distinguish both species and instars of the Limbodessus taxa known so far as larvae. However, as this genus is very speciose and diverse, and the larvae of many species are still unknown, the present key should be considered preliminary. The main purpose at this point is to recognize and evaluate the characters potentially useful to separate species and instars within the genus and to establish a template to which larvae described in the future can be incorporated.

1. Egg bursters present (e.g. Fig. 31 ); secondary setae on cephalic capsule absent (e.g. Figs 31–32 ) (instar I).............. 2

- Egg bursters absent (e.g. Fig. 8); secondary setae on cephalic capsule present (e.g. Fig. 8)......................... .. 13

2. Larger species (HL more than 0.65 mm); occipital foramen strongly reduced (HW/OCW more than 2.20) ( Figs 31–32 , 180– 181 , 238–239 )....................................................................................... 3

- Smaller species (HL less than 0.55 mm); occipital foramen not strongly reduced (HW/OCW less than 2.00) ( Figs 49–50 , 89– 90 , 115–116 , 134–135 , 148–149 , 162–163 , 194–195 , 216–217 , 252–253 )........................................ 5

3. Additional setae on urogomphus present ( Fig. 193 ); nasale with 12 lamellae clypeales ( Fig. 181 ).............................................................................................. L. palmulaoides Watts & Humphreys

- Additional setae on urogomphus absent (Figs 44, 251); nasale with 14 lamellae clypeales ( Figs 32 , 239 )................ 4

4. Nasale longer ( Fig. 31 ); ratio A3/A2 less than 1.40; ratio MP2/MP3 less than 2.50; ratio L3/HW more than 2.90................................................................................. L. bigbellensis (Watts & Humphreys)

- Nasale shorter ( Fig. 238 ); ratio A3/A2 more than 1.50; ratio MP2/MP3 more than 3.30; ratio L3/HW less than 2.70............................................................................ L. yarrabubbaensis Watts & Humphreys

5. Ratio HW/OCW 1.75–1.95............................................................................ 6

- Ratio HW/OCW less than 1.70......................................................................... 7

6. Nasale with 12 lamellae clypeales ( Fig. 217 ); ratio LP2/LP1 more than 1.45....... L. windarraensis (Watts & Humphreys)

- Nasale with 14 lamellae clypeales ( Fig. 135 ); ratio LP2/LP1 less than 1.30............. L. mirandaae Watts & Humphreys

7. Nasale with 14 lamellae clypeales ( Figs 116 , 195 ).......................................................... 8

- Nasale with 12 lamellae clypeales ( Figs 50 , 90 , 149 , 163 , 253 )................................................ 9

8. Nasale with a hole-like structure on ventrodistal surface; ratio A3/A1 more than 2.75.. L. millbilliensis Watts & Humphreys

- Nasale without a hole-like structure on ventrodistal surface; ratio A3/A1 less than 2.65..... L. pulpa (Watts & Humphreys)

9. Smaller species (HL less than 0.35 mm); ratio MP2/MP1 more than 2.10; ratio LP2/LP1 more than 2.40.......................................................................................... L. morgani (Watts & Humphreys)

- Larger species (HL more than 0.35 mm); ratio MP2/MP1 less than 1.90; ratio LP2/LP1 less than 2.00................ 10

10. Nasale with a strongly developed half-circle of dense spinulae on lateroventral margins ( Fig. 90 ) L. leysi Watts & Humphreys

- Nasale without a strongly developed half-circle of dense spinulae on lateroventral margins ( Figs. 50 , 163 , 253 )......... 11

11. Ratio HW/OCW more than 1.60; ratio LP2/LP1 less than 1.20..................... L. nambiensis Watts & Humphreys

- Ratio HW/OCW less than 1.45; ratio LP2/LP1 more than 1.40............................................... 12

12. Ratio A3/A1 more than 2.80; ratio MP2/MP3 = 1.80............................ L. challaensis (Watts & Humphreys)

- Ratio A3/A1 less than 2.70; ratio MP2/MP3 = 2.00........................... L. yuinmeryensis (Watts & Humphreys)

13. Spiracles on mesothorax and abdominal segments I-VII absent (instar II)....................................... 14

- Spiracles on mesothorax and abdominal segments I-VII present (instar III)...................................... 27

14. Stemmata present; two rows of secondary hair-like setae present on ventral surface of parietal; epigean species........ 15

- Stemmata absent; two rows of secondary hair-like setae on ventral surface of parietal absent; stygobitic species........ 16

15. Legs longer (L3 1.15–1.30 mm); secondary setae on protarsus present; metatibia and metatarsus with more than 5 secondary setae................................................................................ L. amabilis (Clark)

- Legs shorter (L3 0.95–1.05 mm); secondary setae on protarsus absent; metatibia and metatarsus with less than 4 secondary setae............................................................................... L. shuckardii (Clark)

16. Secondary setae on urogomphus present................................................................. 17

- Secondary setae on urogomphus absent.................................................................. 20 18. Occipital foramen not strongly reduced (HW/OCW 1.90–2.00) ( Fig. 27 ).......... L. barwidgeeensis Watts & Humphreys

- Occipital foramen strongly reduced (HW/OCW more than 2.60) (Fig. 107)..................................... 19

19. Occipital suture absent (Fig. 107); nasale with more than 200 lamellae clypeales; ratio A3/A1 more than 2.50................................................................................... L. macrohinkleri Watts & Humphreys

- Occipital suture present; nasale with less than 100 lamellae clypeales; ratio A3/A1 less than 2.20.............................................................................................. L. raesideensis (Watts & Humphreys)

20. Protibia without secondary setae....................................................................... 21

- Protibia with 1–3 secondary setae...................................................................... 24

21. Seta AN2 absent; ratio HW/OCW more than 1.75................................. L. hinkleri (Watts & Humphreys)

- Seta AN2 present; ratio HW/OCW less than 1.75.......................................................... 22

22. Nasale with a hole-like structure on ventrodistal surface; lateral margins of nasale inflated in dorsal view....................................................................................... L. millbilliensis Watts & Humphreys

- Nasale without a hole-like structure on ventrodistal surface; lateral margins of nasale not inflated in dorsal view........ 23

23. Smaller species (HL less than 0.45 mm); nasale with less than 25 lamellae clypeales; ratio MP2/MP3 less than 2.20; ratio LP2/ LP1 more than 1.60........................................................ L. morgani (Watts & Humphreys)

- Larger species (HL more than 0.45 mm); nasale with more than 25 lamellae clypeales; ratio MP2/MP3 more than 2.70; ratio LP2/LP1 less than 1.30........................................................ L. pulpa (Watts & Humphreys)

24. Protarsus with 1 secondary seta; protibia with 3 secondary setae.................. L. windarraensis (Watts & Humphreys)

- Protarsus without secondary setae; protibia with 1 secondary seta............................................. 25

25. Ratio MP2/MP1 less than 1.05; ratio U/HW less than 2.15.......................... L. ordinarius Watts & Humphreys

- Ratio MP2/MP1 more than 1.10; ratio U/HW more than 2.20................................................ 26

26. Ratio A3/A1 more than 2.20; ratio MP2/MP3 more than 2.40; ratio L3/HW more than 2.45.................................................................................................. L. masonensis (Watts & Humphreys)

- Ratio A3/A1 less than 2.20; ratio MP2/MP3 less than 2.40; ratio L3/HW less than 2.45.... L. yuinmeryensis (Watts & Humphreys)

27. Stemmata present (Figs 8, 12, 14, 18, 22); two rows of secondary hair-like setae present on ventral surface of parietal ( Fig. 23 ); epigean species..................................................................................... 28

- Stemmata absent (Figs 45, 63, 67, 69, 73, 77, 81, 85, 103, 111, 129, 176, 208, 212, 230, 234, 266); two rows of secondary hairlike setae on ventral surface of parietal absent; stygobitic species............................................. 32

28. Secondary setae on urogomphus absent (Figs 11, 13, 26).................................................... 29

- Secondary setae on urogomphus present (Figs 17, 21)...................................................... 31

29. Smaller species (HL less than 0.62 mm)................................................... L. compactus (Clark)

- Larger species (HL more than 0.62 mm)................................................................. 30

30. Legs longer (L3 1.67–1.69 mm); anterodorsal secondary setae on tarsus present (Fig. 9).............. L. amabilis (Clark)

- Legs shorter (L3 1.38–1.42 mm); anterodorsal secondary setae on tarsus absent ( Fig. 24 )............. L. shuckardii (Clark)

31. Legs longer (L3 1.94–2.01 mm); urogomphus longer (U 1.62–1.66 mm); metacoxa with more than 50 secondary setae.......................................................................................... L. inornatus (Sharp)

- Legs shorter (L3 1.73 mm); urogomphus shorter (U 1.35 mm); metacoxa with less than 50 secondary setae..... L. praelargus (Lea)

32. Occipital foramen reduced (HW/OCW more than 1.95) (Figs 45, 67, 69, 212, 234); secondary setae on urogomphus present (Figs 48, 68, 215, 237); metatarsus with more than 10 secondary setae......................................... 33

- Occipital foramen well developed (HW/OCW less than 1.90) (Figs 63, 73, 77, 81, 85, 103, 111, 129, 176, 208, 230, 266); secondary setae on urogomphus absent (Figs 66, 76, 80, 84, 88, 106, 114, 133, 179, 211, 233, 269); metatarsus with less than 6 secondary setae..................................................................................... 37

33. Nasale with less than 110 lamellae clypeales.............................................................. 34

- Nasale with more than 120 lamellae clypeales............................................................ 35

34. Nasale with 55–65 lamellae clypeales; lateral projections of nasale visible in dorsal view (Fig. 45); ratio HW/OCW more than 2.80.................................................................. L. bigbellensis (Watts & Humphreys)

- Nasale with 90–100 lamellae clypeales; lateral projections of nasale not visible in dorsal view (Fig. 67); ratio HW/OCW less than 2.10................................................................... L. cooperi Watts & Humphreys

35. Occipital suture absent (Fig. 234)............................................ L. yandalensis Watts & Humphreys

- Occipital suture present (Figs 69, 212).................................................................. 36

36. Nasale broad ( Fig. 212 ); femur with more than 30 secondary setae ( Figs 213–214 )... L. raesideensis (Watts & Humphreys)

- Nasale narrow (Fig. 69); femur with less than 20 secondary setae (Figs 70–71)........ L. eberhardi (Watts & Humphreys)

37. Lateral margins of nasale inflated in dorsal view (Figs 85, 103, 129)........................................... 38

- Lateral margins of nasale not inflated in dorsal view (Figs 77, 81, 176, 230, 266)................................. 40

38. Nasale with a half-circle of dense spinulae on lateroventral margins (Fig. 103); nasale without a hole-like structure on ventrodistal surface................................................................... L. leysi Watts & Humphreys

- Nasale without a half-circle of dense spinulae on lateroventral margins (Figs 85, 129); nasale with a hole-like structure on ventrodistal surface (Fig. 130)............................................................................ 39

39. Seta AN2 present; distal half of mandible narrow (Fig. 129); nasale with 50–60 lamellae clypeales............................................................................................ L. millbilliensis Watts & Humphreys

- Seta AN2 absent; distal half of mandible broad (Fig. 85); nasale with 30–40 lamellae clypeales.. L. hinkleri (Watts & Humphreys) .................................................................... L. fridaywellensis (Watts & Humphreys)

- Larger species (HL 0.67 mm); metathoracic claw 0.30–0.35 times as long as metatarsus................................................................................................... L. yuinmeryensis (Watts & Humphreys)

42. Nasale with more than 55 lamellae clypeales........................................ L. raeae Watts & Humphreys

- Nasale with less than 55 lamellae clypeales............................................................... 43

43. Mandible more than 5.00 times longer than broad.......................................................... 44

- Mandible less than 4.80 times longer than broad........................................................... 45

44. Anteroventral secondary setae on protibia absent (Fig. 64); secondary setae on protarsus absent (Figs 64–65).................................................................................... L. challaensis (Watts & Humphreys)

- Anteroventral secondary setae on protibia present (Fig. 231); secondary setae on protarsus present (Figs 231–232).............................................................................. L. windarraensis (Watts & Humphreys)

45. Secondary setae on protarsus present (Fig. 178).................................. L. ordinarius Watts & Humphreys

- Secondary setae on protarsus absent.................................................................... 46

46. Anteroventral secondary setae on protibia present (Fig. 74); posteroventral secondary setae on metatarsus present....................................................................................... L. exilis Watts & Humphreys

- Anteroventral secondary setae on protibia absent; posteroventral secondary setae on metatarsus absent............... 47

47. Mesofemur with 11 secondary setae; ratio MP/LP more than 1.50.................. L. masonensis (Watts & Humphreys)

- Mesofemur with 9 secondary setae; ratio MP/LP less than 1.50................... L. hillviewensis (Watts & Humphreys)

Figures

FIGURES 31–39. Limbodessus bigbellensis, first-instar larva. 31, cephalic capsule, dorsal aspect; 32, cephalic capsule, ventral aspect; 33, right antenna, dorsal aspect; 34, left antenna, ventral aspect; 35, right maxilla, dorsal aspect; 36, left maxilla, ventral

FIGURES 180–188. Limbodessus palmulaoides, first-instar larva. 180, cephalic capsule, dorsal aspect; 181, cephalic capsule,

FIGURES 238–246. Limbodessus yarrabubbaensis, first-instar larva. 238, cephalic capsule, dorsal aspect; 239, cephalic capsule, ventral aspect; 240, right antenna, dorsal aspect; 241, left antenna, ventral aspect; 242, right maxilla, dorsal aspect;

FIGURES 49–57. Limbodessus challaensis, first-instar larva. 49, cephalic capsule, dorsal aspect; 50, cephalic capsule, ventral aspect; 51, right antenna, dorsal aspect; 52, left antenna, ventral aspect; 53, right maxilla, dorsal aspect; 54, left maxilla, ventral

FIGURES 89–97. Limbodessus leysi, first-instar larva. 89, cephalic capsule, dorsal aspect; 90, cephalic capsule, ventral aspect;

FIGURES 115–123. Limbodessus millbilliensis, first-instar larva. 115, cephalic capsule, dorsal aspect; 116, cephalic capsule,

FIGURES 134–142. Limbodessus mirandaae, first-instar larva. 134, cephalic capsule, dorsal aspect; 135, cephalic capsule,

FIGURES 148–156. Limbodessus morgani, first-instar larva. 148, cephalic capsule, dorsal aspect; 149, cephalic capsule, ventral aspect; 150, right antenna, dorsal aspect; 151, left antenna, ventral aspect; 152, right maxilla, dorsal aspect; 153, left

FIGURES 162–170. Limbodessus nambiensis, first-instar larva. 162, cephalic capsule, dorsal aspect; 163, cephalic capsule,

FIGURES 194–202. Limbodessus pulpa, first-instar larva. 194, cephalic capsule, dorsal aspect; 195, cephalic capsule, ventral aspect; 196, right antenna, dorsal aspect; 197, left antenna, ventral aspect; 198, right maxilla, dorsal aspect; 199, left maxilla,

FIGURES 216–224. Limbodessus windarraensis, first-instar larva. 216, cephalic capsule, dorsal aspect; 217, cephalic capsule,

FIGURES 252–260. Limbodessus yuinmeryensis, first-instar larva. 252, cephalic capsule, dorsal aspect; 253, cephalic capsule,

FIGURES 189–193. Limbodessus palmulaoides, first-instar larva. 189, left metathoracic leg, anterior aspect; 190, right metathoracic leg, posterior aspect; 191, abdominal segment VIII, dorsal aspect; 192, abdominal segment VIII, ventral aspect; 193, right urogomphus, dorsal aspect. Scale bars = 0.10 mm.

FIGURES 27–30. Limbodessus barwidgeeensis, second-instar larva. 27, head, dorsal aspect; 28, left prothoracic leg, anterior aspect; 29, right prothoracic leg, posterior aspect; 30, abdominal segment VIII and urogomphi, dorsal aspect. Scale bars = 0.15 mm.

FIGURES 22–26. Limbodessus shuckardii, third-instar larva. 22, head, dorsal aspect; 23, head, ventral aspect; 24, left prothoracic leg, anterior aspect; 25, right prothoracic leg, posterior aspect; 26, abdominal segment VIII and urogomphi, dorsal aspect. Scale bars = 0.10 mm.

FIGURES 212–215. Limbodessus raesideensis, third-instar larva. 212, head, dorsal aspect; 213, left prothoracic leg, anterior