Cricotopus

Drayson, Nick, Cranston, Peter S. & Krosch, Matt N., 2015, Taxonomic review of the chironomid genus Cricotopus v. d. Wulp (Diptera: Chironomidae) from Australia: keys to males, females, pupae and larvae, description of ten new species and comments on Paratrichocladius Santos Abreu, Zootaxa 3919 (1), pp. 1-40 : 36

Key to larvae of Australian Cricotopus & Paratrichocladius

1 Outer edge of mandible strongly crenulate ( Fig. 10 A, B)....................................................... 2

- Outer edge of mandible smooth excepting notch or only subtly crenulate ( Fig. 10 C, D).............................. 7

2 Inner edge of mandible serrate ( Fig. 10 A)..................................................... C. acornis sp. n.

- Inner edge of mandible smooth ( Fig. 10 B).................................................................. 3

3 Darkening of mandible extending only as far as mola ( Fig. 10 B)......................... C. albitarsis Hergstrom sp. n.

- Darkening of mandible extending proximally towards base of mandible ( Figs. 11 C, 12C)............................. 4

4 Antennal blade not extending past 4th segment ( Fig. 11 C). Head mid-brown, with weak contrast to mandible and mentum......................................................................................... C. howensis sp. n.

- Antennal blade extending to apex of antenna or beyond (Fig. 12C). Head pale, with strong contrast to dark apical mandible and mentum............................................................................................. 5

5 Lauterborn organs small, less than 0.5 length of 3rd segment (Fig. 12C)................................ C. wangi sp. n.

- Lauterborn organs large, encompassing total 3rd antennal segment (Fig. 12B)...................................... 6

6 Mola broad and very flat; seta subdentalis narrow ending in simple point; apical mandible tooth 2x 1st inner, ‘kitchen knife’ shaped (Fig. 12B).............................................................. C. varicornis sp. n. (part, s.s.)

- Mola broad and squared off; seta subdentalis broad ending in hooked point; apical mandible tooth 1.5x length of 1st inner and similar in shape ( Fig. 11 B)................................................................. C. hillmani sp. n.

7 Inner edge of mandible serrate (Fig. 12A).................................................................. 8

- Inner edge of mandible smooth ( Fig. 11 A)................................................................. 12

8 Mentum golden-brown with median area paler (Fig. 12A)..................................................... 9

- Mentum evenly mid- to dark brown ( Fig. 10 A)............................................................. 11

9 Pigmented area of mandible and mentum in modest contrast to mid-brown head (Fig. 12A)........... C. tasmania sp. nov.

- Pigmented area of mandible and mentum in strong contrast to brown head ( Fig. 11 D)............................... 10

10 Pigmented area of mandible not extending basally past the mola/notch........................ ‘ divergent parbicinctus’

- Pigmented area of mandible extending at least to external seta ( Fig. 11 D)............... C. parbicinctus Hergstrom sp. n.

11 Mid-brown mandible pigment extends to external seta in strong contrast to pale head. Mola broad, rounded. Median mentum tooth narrow with 2nd lateral teeth clearly smaller than 1st ( Fig. 10 C).......................... C. annuliventris (Skuse)

- Dark brown-black mandible pigment extends to base and less strongly contrast to mid-brown head; mola narrow. Median men- tum tooth broad, rounded, with 2nd lateral teeth not smaller than 1st........................... ‘ divergent annuliventris’

12 Mandible pigment extending to base of mandible; apical mandible tooth subequal to 1st inner tooth, both near 2x 2nd inner tooth ( Fig. 11 A)........................................................................ C. conicornis sp. n.

- Mandible pigment extending to mola / external seta; apical mandible tooth 1.5x> 1st inner tooth; 1st inner tooth <1.5x size of 2nd inner tooth....................................................................................... 13

13 Lauterborn organs large, dilate, extending to apex of 3rd antennal segment; antennal segments 2–5 short, subequal (Fig. 12b)....................................................................... C. varicornis sp. n. (part, var. ‘ cooki’)

- Lauterborn organs moderately developed, tapering; 2nd antennal segment equal to 3+4, with short 5th................... 14

14 Apical mandible tooth flanged, giving ‘kitchen knife’ shape, inner teeth aligned with inner edge of apical tooth. Mandible dark pigment extends to external seta.................................................. Paratrichocladius ‘M1/FNQ1’

- Apical mandible tooth same shape as inner teeth. Mandible dark pigment extends distal to mola....................... 15

15 Lateral mental teeth bulbous basally and pointed apically. 1st inner mandible tooth equal in length to 2nd tooth. Antennal blade extends to apex of antenna........................................................ Paratrichocladius ‘SW QLD’

- Lateral mental teeth non-bulbous basally; 1st inner mandible tooth 1.5x longer than 2nd tooth; antennal blade extends to apex of 4th segment ( Fig. 10 D).................................................................. C. brevicornis sp. n.

Figures

FIGURE 10. Cricotopus larva, mentum, mandible, antenna. A. C. acornis, B. C. albitarsis, C. C. annuliventris, D. C. brevicornis.

FIGURE 11. Cricotopus larva, mentum, mandible, antenna. A. C. conicornis, B. C. hillmani, C. C. howensis, D. C. parbicinctus.