Acrotrichis

Darby, Michael, 2015, Studies of Bolivian Ptiliidae (Coleoptera) 2: The subfamily Acrotrichinae including two new genera Petrotrichis and Microtrichis, and eight new species of Acrotrichis, Zootaxa 3999 (2), pp. 190-210 : 192

Key to the known species of Acrotrichis from Bolivia

1. Elytral cells bearing microtrichiae giving a pruinose appearance ( Figs.2 G, 9I)...................................... 2

- Elytral cells without microtrichiae........................................................................ 3

2. Larger species> 1.1 mm, elytra with a humeral epipleuron ( Fig.9 H) and anterior border of pygidium with fringe of setae ( Fig. 4 J)........................................................................................ A. segmenta

- Smaller species <1.1 mm. Anterior border of pygidium without setae, elytra widest at middle................ A. armillata

3. Pygidium with several prominent longer setae and anterior border without a fringe of setae........................... 4

- Pygidium without any prominent setae and anterior border fringed with setae...................................... 5

4. Smaller species +/- 0.9 mm, length of antennomeres 4–7 3x width, elytra widest at middle, spermatheca with a single row of small coils ( Fig. 8 E), aedeagus distinctive ( Fig. 8 F)...................................................... A. nashi

- Larger species> 1.0 mm, length of antennomeres 4–7 4x width, elytra widest near shoulder, spermatheca with a large number of loose coils ( Fig. 3 G)......................................................................... A. cincinna

5. Metaventral separation of metacoxae very narrow ( Fig.4 G), aedeagus with a pointed tip ( Fig. 4 E) and male ventrite six with pairs of distinctive large and curved setae ( Fig. 4 H)................................................... A. cornuta

- Metacoxal separation much wider.........................................................................6

6. Dark species, pronotal margins when viewed at 45° evenly curved to hind angles without an insinuation ( Fig. 6 B), spermathca distinctive ( Fig.6 D).......................................................................... A. inlecebrosa

- Yellowish species, pronotal borders when viewed at 45° with a sinuation before the hind angles....................... 7

7. Proportionately narrower and longer species, metacoxal separation very wide ( Fig. 7 G), spermatheca with a very long folded duct ( Fig.7 D)................................................................................... A. linea

- Proportionately shorter and broader species, metacoxal separation narrower ( Fig. 5 G), spermatheca without a long folded duct ( Fig. 5 E).................................................................................. A. corpulenta

Figures

FIGURE 2. A. armillata. A, habitus; B, side of pronotum viewed at 45 °; C, mentum and submentum showing chaetotaxy; D, antennomeres 3 – 11; E. spermatheca; F, pygidium showing principal setae; G, pronotum and elytra showing cell structure x 2420; H, mesoventrum x 455; I, metaventral posterior margin and coxal plates x 455.

FIGURE 9. A. segmenta. A, habitus, large immature specimen; B, habitus, small mature specimen; C, antennomeres 3 – 11; D, side of pronotum viewed at 45 °; E, spermatheca, immature specimen; Fa & b, spermatheca mature specimen; G, mentum and submentum showing chaetotaxy x 820; H. elytron; I, elytral cells showing microtrichiae x 2960; J, metaventral posterior margin and coxal plates x 465; K, mesoventrum x 410; L, pygidium; M. sternite.

FIGURE 4. A. cornuta. A, habitus; B, side of pronotum viewed at 45 °; C, antennomeres 3 – 11; D, spermatheca; E, aedeagus; F, mesoventrum x 580; G, metaventral posterior margin and coxal plates x 635; H, male ventrites six and seven x 1820; I, mentum and submentum x 1220; J, pygidium.

FIGURE 8. A. nashi A, habitus; B, side of pronotum viewed at 45 °; C, antennomeres 3 – 11; D, pygidium showing principal setae; E, spermatheca; F, aedeagus; G, male ventrite seven; H, mentum and submentum x 1000; I, mesoventrum x 510; J, metaventral posterior margin and coxal plates x 510; K, male ventrite six x 1900.

FIGURE 3. A. cincinna. A, habitus; B, side of pronotum viewed at 45 °; C, antennomeres 3 – 11; D, aedeagus; E, mentum and submentum x 1320; F, pygidium, G, spermatheca; H, metaventral posterior margin and coxal plates x 455; I, mesoventrum x 470.

FIGURE 6. A. inlecebrosa. A, habitus; B, side of pronotum viewed at 45 °; C, antennomeres 3 – 11; D, spermatheca; E, mentum and submentum x 890; F, mesoventrum x 470; G, metaventral posterior margin and coxal plates x 460.

FIGURE 7. A. linea. A, habitus; B, side of pronotum viewed at 45 °; C, antennomeres 3 – 11; D, spermatheca; E, mentum and submentum showing chaetotaxy; F, mesoventrum x 465; G, metaventral posterior margin and coxal plates x 465.

FIGURE 5. A. corpulenta. A, habitus; B, side of pronotum viewed at 45 °; C, antennomeres 3 – 11; D, aedeagus; E, spermatheca; F, mentum and submentum x 960; G, mesoventrum x 465; H, metaventral posterior margin and coxal plates x 455; I, male ventrites six and seven x 1020; I, pygidium.