Acrotrichis

Darby, Michael, 2014, Studies of Madagascan Ptiliidae (Coleoptera) 3: The genus Acrotrichis including twenty seven new species, Zootaxa 3866 (2), pp. 151-201 : 156-157

publication ID

https://doi.org/ 10.11646/zootaxa.3866.2.1

publication LSID

lsid:zoobank.org:pub:2165AC20-3607-4CF2-A1A6-DB4CA45D7E22

DOI

https://doi.org/10.5281/zenodo.6130997

persistent identifier

https://treatment.plazi.org/id/F3388D27-5129-3C23-E6EB-FEE34B366D13

treatment provided by

Plazi

scientific name

Acrotrichis
status

 

Key to the known species of Acrotrichis View in CoL from Madagascar

Note: dissection of genitalia is an essential prerequisite for most determinations (although it is sometimes possible to see the shape of the spermatheca in specimens in alcohol without the need for dissection).

1. Posterior margin of mesosternal collar strongly sloping at humeri (as Fig. 3 View FIGURE 3. A F), larger species (> 0.75 mm)............... 2

- Posterior margin of mesoventral collar barely sloping at humeri (as Fig. 10 View FIGURE 10. A G), smaller species (<0.75 mm)............. 25

2. Sides of pronotum and elytra with outstanding setae (note: if there is doubt as to whether these have become abraded, the ante- rior margin of the pygidium without setae)...................................................... A. discoloroides View in CoL

- Sides of pronotum and elytra without outstanding setae........................................................ 3

3. Mesoventral collar with a median pointed projection ( Fig. 6 View FIGURE 6. A F).................................................. 4

- Mesoventral collar without a median pointed projection....................................................... 5

4. Smaller species with a more pronounced curve to the pronotal margins ( Fig. 31 View FIGURE 31. A B)...................... A. superbioides View in CoL

- Larger, broader species with a less pronounced curve to the pronotal margins ( Fig. 6 View FIGURE 6. A B)....................... A barclayi View in CoL

5. Mesoventral collar with a clearly marked median keel ( Fig. 7 View FIGURE 7. A H)................................................. 6

- Mesoventral collar without a median keel.................................................................. 8

6. Sides of pronotum more rounded ( Fig. 35 View FIGURE 35. A B), antennomeres 3–8 longer ( Fig. 35 View FIGURE 35. A C).......................... A. tuberosa View in CoL

- Sides of pronotum less rounded and antennomeres 3–8 shorter.................................................. 7

7. Keel on mesoventral collar more pronounced ( Fig. 7 View FIGURE 7. A H), pronotal sides less curved ( Fig. 7 View FIGURE 7. A B), spermatheca distinctive ( Figs. 7 View FIGURE 7. A D)........................................................................................... A. bibula View in CoL

- Keel narrower and less pronounced, pronotal sides more curved ( Fig. 24 View FIGURE 24. A B), spermatheca distinctive ( Fig. 24 View FIGURE 24. A D).. A. malitiosa View in CoL

8. Submentum with 12+ setae.............................................................................. 9

- Submentum with less than 12 setae....................................................................... 13

9. Setae on submentum long (some as long as the mentum) and directed posteriorly ( Fig. 12 View FIGURE 12. A F), pronotum much broader than the elytra....................................................................................... A. cuspida View in CoL

- Setae on submentum shorter, width of pronotum not so pronounced............................................. 10

10. Mentum with 8 setae arranged 4.2.2 ( Fig. 4 View FIGURE 4. A E)....................................................... A. africana View in CoL

- Mentum with more than 8 setae arranged differently......................................................... 11

11. Smaller (<0.90 mm), reddish brown species, mentum setae arranged 3.4.10 + ( Fig. 5 View FIGURE 5. A I).................... A. africanoides View in CoL

- Larger (> 0.9 mm), blackish/dark brown species, mentum setae arranged differently................................ 12

12. Submentum with +/- 13 setae; mentum setae arranged 5.2.4........................................... A. impressa View in CoL

- Submentum with +/- 18 setae; mentum setae arranged 5.3.5......................................... A. subafricana View in CoL

13. Hind angles of pronotum rounded, not or barely angled....................................................... 14

- Hind angles of pronotum pointed or clearly angled.......................................................... 15

14. Smaller, very rounded species with a distinctive spermatheca ( Fig. 32 View FIGURE 32. A D)............................... A. tampoketsae View in CoL

- Larger, flatter species with short and broad elytra.................................................... A. truncata View in CoL

15. Elytra distinctly narrowed posteriorly, very large species (+/- 1.22 mm), mentum with a pair of long setae at each of the anterior corners ( Fig. 29 View FIGURE 29. A G).............................................................................. A. strenua View in CoL

- Elytra parallel sided or rounded, not narrowed posteriorly, smaller species........................................ 16

16. Sides of pronotum sinuate before the hind angle (often the sinuation is slight).................................... 17

- Sides of pronotum clearly rounded or straight before the hind angles, not sinuate.................................. 20

17. Metaventral posterior margin between metacoxae very short ( Fig. 22 View FIGURE 22. A F).................................. A. loganovi

- Metaventral posterior margin between metacoxae longer ( Fig. 16 View FIGURE 16. A J)............................................. 18

18. Sides of pronotum strongly curved before hind angles and only very slightly sinuate ( Fig. 23 View FIGURE 23. A B); male genitalia distinctive.............................................................................................. A. magnifica View in CoL

- Pronotal margin moderately curved...................................................................... 19

19. Male ventrites six and seven very distinctive ( Figs. 6 View FIGURE 6. A F,G)............................................ A. hammondi View in CoL

- Male ventrite six with a few narrow spines only ( Fig. 27 View FIGURE 27. A G) and seven without any distinctive features......... A. perexigua View in CoL

20. Mentum with 13 setae in +/- four rows and sides of pronotum feebly curved ( Figs. 9 View FIGURE 9. A B,H)..................... A. clareae View in CoL

- Mentum with fewer setae and more strongly curved pronotal sides.............................................. 21

21. Posterior margin of metaventrum between metacoxae short ( Fig. 17 View FIGURE 17. A H)..................................... A. heissi View in CoL

- Posterior margin of metaventrum between metacoxae broader ( Fig. 3 View FIGURE 3. A G)......................................... 22

22. Large blackish species (<0.95 mm)................................................................ A. absona View in CoL

- Smaller (> 0.9 mm) black or reddish brown species.......................................................... 23

23. Black very shining species, aedeagus with a pointed tip ( Fig. 21 View FIGURE 21. A D)......................................... A. lauta View in CoL

- Reddish brown, less shining species...................................................................... 24

24. Ventrite six of male with long fringe of spines, aedeagus distinctive ( Fig. 11 View FIGURE 11. A I)............................. A. cursitans View in CoL

- Ventrite six of male with 10 or less spines................................................................. 25

25. Ventrite six of male with one spine ( Fig. 20 View FIGURE 20. A G) aedeagus pear shaped ( Fig. 20 View FIGURE 20. A E)........................... A. lacrimosa View in CoL

- Ventrite six of male without a single spine................................................................ 26

26. Sides of pronotum evenly rounded to hind angle, not sinuate, yellow species ( Fig. 13 View FIGURE 13. A B)...................... A. difficilis View in CoL

- Sides of pronotum sinuate before the hind angle (in most cases the sinuation is slight).............................. 27

27. Larger species (> 0.76 mm)......................................................................... A.hova View in CoL

- Smaller species (> 0.74 mm)............................................................................ 28

28. Yellowish brown species with very sharply pointed pronotal hind angles ( Fig. 8 View FIGURE 8. A B)............................ A. boothi View in CoL

- darker species, hind angles of pronotum less pointed ( Fig. 24 View FIGURE 24. A D)................................................ 29

29. Very small paler species (0.53 mm). The sinuation in the pronotal sides barely detectable.................... A. terminalis View in CoL

- larger darker species> 0.58 mm ......................................................................... 30

30. The six small species in this category: colini View in CoL , exigua View in CoL , minuscula View in CoL , obscura View in CoL , and perfida View in CoL are very difficult to separate on external criteria particularly when specimens are teneral and are best determined by examination of the genitalia, see Figs in the species descriptions.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Ptiliidae

GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF