Ischalia Pascoe, 1860

Kazantsev, Sergey V. & Telnov, Dmitry, 2019, New species of Ischalia Pascoe, 1860 (Coleoptera: Ischaliidae), with a key to aposematically coloured species from continental Asia, and new notes on their mimicry, Zootaxa 4555 (3), pp. 441-450 : 448-449

Key to the extant Ischalia Pascoe, 1860 species with aposematic coloration from continental Asia

No keys are available for the entire genus of Ischalia . The first attempt to key the Oriental Ischalia made by Saitô (2003) omitted some species. Later on, Young (2011) keyed the extant blue elytra Ischalia . Two informal groups, Ischalia (s. str.) patagiata group and I. (s. str.) luteolineata group, were established and keyed by Saitô & Young (2015). Since these species groups were based only on elytral colour pattern ( Saitô & Young 2015: 180), while other important morphological features were ignored (see the key below), we are not referring to these species groups in our key.

This is an original key to extant species of Ischalia with pale (yellow or ochre coloured) elytra, which in most species is supplemented with a more or less distinct, longitudinal dark sutural marking. Only species hitherto reported from Asian mainland are considered (e.g., endemics of the Greater Sunda Islands, Japanese Archipelago, Kuril Islands, the Philippines, and Taiwan are not included to the present key). Different previous authors often used different characters for descriptions of Ischalia species. Therefore, some of previous descriptions are rather incomplete and don’t include certain important morphological features. Since not all species were available for this study (and there was no such goal as to revise all species), this key is partly based on a combination of various characters used by other authors.

1 Elytral humeral carinae absent; metathoracic wings absent......................2 [subgenus Eupleurida LeConte, 1862 ]

- Elytral humeral carinae present; metathoracic wings present, in most cases fully developed (rarely reduced)................................................................................... 3 [subgenus Ischalia s. str. Pascoe, 1860]

2 Black area of elytra subopaque; pronotum with lateral margins emarginate near posterior angles; scutellum broader, triangular, slightly longer than wide; female with subparallel elytra......................... I. (E.) aptera Gusakov et Telnov, 2007

- Black area of elytra glossy; pronotum with lateral margins straight, not emarginate near posterior angles; scutellum more slen- der, distinctly longer than wide; female with suboval elytra............................ I. (E.) sichuanensis Young, 2008

3 Elytral sutural carinae dark coloured for much of all their length................................................ 4

- Elytral sutural carinae pale for much of all their length....................................................... 10

4 Vertex dorsally with two more or less distinct longitudinal ridges................................................ 5

- Vertex dorsally without longitudinal ridges................................................................. 6

5 Brachypterous; anterior portion of pronotum distinctly gibbous in lateral view; elytral apices black and sinuate...................................................................................... I. (I.) brachyptera Nikitsky, 1994

- Metathoracic wings fully developed; anterior portion of pronotum concave, flat or slightly gibbous in lateral view; elytral apices pale, not sinuate.............................................................. I. (I.) martensi Paulus, 1971

6 Anterior portion of pronotum strongly gibbous in lateral view............................. I. (I.) fischeri Young, 2008

- Anterior portion of pronotum not or indistinctly gibbous in lateral view........................................... 7

7 Scutellum strongly emarginate posteriorly................................ I. (I.) anhuiensis Kazantsev et Young, 2010

- Scutellum truncate or rounded posteriorly, not emarginate..................................................... 8

8 Lateral pronotal margins slightly projected (angulate widened) laterally midway along their length; anterior margin of pronotum deeply sinuate mesally......................................................... I. (I.) suturalis Blair, 1912

- Lateral pronotal margins evenly rounded from front to back; anterior margin of pronotum not or shallowly sinuate mesally.. 9

9 Mesothoracic episterna widely separated............................................ I. (I.) gialaiensis Young, 2008

- Mesothoracic episterna nearly contiguous anteriorly............................. I. (I.) lama Kazantsev et Young, 2010

10 Elytra entirely pale................................................................................... 11

- Elytra with dark longitudinal vitta at least in part of their length................................................ 12

11 Vertex dorsally with two more or less distinct longitudinal ridges............................. I. (I.) holzschuhi sp. nov.

- Vertex dorsally without longitudinal ridges........................................... I. (I.) chinensis Young, 1976

12 Dark longitudinal vittae of elytra developed in apical half of elytra, dark coloration covering elytral apices.................................................................................................... I. (I.) blairi Pic, 1912

- Elytral apices pale; dark longitudinal vittae of elytra present in basal half or all along elytral length.................... 13

13 Dark longitudinal vittae of elytra narrow, less prominent...................................................... 14

- Dark longitudinal vittae of elytra broad, well developed and prominent (in I. acco dark colouration of elytra is broad but less contrast and not prominent)............................................................................. 16

14 Scutellum very shallowly emarginate posteriorly, almost truncate................... I. (I.) sasajii Satô et Ohbayashi, 2001

- Scutellum strongly emarginate posteriorly................................................................. 15

15 Parameres with median lobe longer; parameral blade rounded distally............................ I. (I.) ancora sp. nov.

- Parameres with median lobe comparatively shorter; parameral blade emarginate distally........... I. (I.) laosensis sp. nov.

16 Anterior portion of pronotum gibbous in lateral view........................................................ 17

- Anterior portion of pronotum not or indistinctly gibbous in lateral view.......................................... 18

17 Dark longitudinal coloration extensive, covering at least half of elytron’s width; dark elytral vittae longer, reaching the lateral discal elytral carinae in their apical area.............................................. I. (I.) patagiata Lewis, 1887 - Dark longitudinal coloration less extensive, covering about third of elytron’s width; dark elytral vittae shorter, not reaching the lateral discal elytral carinae in their apical area....................................... I. (I.) nepalensis Paulus, 1971

18 Dark longitudinal coloration extensive, covering more than half of elytron’s width; total body length 5.0–7.0 mm........ 19

- Dark longitudinal coloration less extensive, covering less than half elytron’s width; total body length about 5.0 mm; pronotum broader transverse................................................................ I. (I.) nigrovittata Pic, 1940

19 Smaller, total body length about 5.0– 5.5 mm; pronotum broadly emarginate at anterior margin................................................................................................. I. (I.) acco Satô et Ohbayashi, 2001

- Larger, total body length 6.5–7.0 mm; lateral discal elytral carinae curving inwardly toward sutural carinae in apical part of each elytron and connected with them; pronotum straight at anterior margin...... I. (I.) tsuyukii Ohbayashi et Toyama, 1994