Key to species of Agrilus purpurifrons species-group

Agrilus extrarmatus Curletti, 2003 (see Fig. 14 in Curletti, 2003) is not included in the key, but it is tentatively assigned to this group until the male is available. The type was not studied but its published image displays a transverse pronotum and spinate elytral apices which indicate affinity to this species-group despite the vertex being wider and frons lacking a distinct medial impression.

1 Pygidium arcuate; pronotal lobe obvious................................................................... 2

- Pygidium spinate; pronotal lobe vestigial or absent........................................................... 4

2 Prehumerus carinal, arcuate; size 8.4–8.8 mm; Laos; (habitus Fig. 2B)......................... A. stoneae Baudon, 1968

- Prehumerus absent..................................................................................... 3

3 Prosternal process in male with obvious medial carina; size 9.6–10.5 mm; Malaysia (Pahang); (habitus Fig. 1A, aedeagus Fig. 2E)............................................................................... A. cameronius sp. nov.

- Prosternal process in male flat; size 8.3–10 mm; Peninsular Malaysia, Singapore, Borneo; (habitus Fig. 2C, aedeagus Fig. 2K)................................................................................... A. trito Deyrolle, 1864

4 Elytra without pairs of tomentose spots.................................................................... 5

- Elytra with 1–3 pairs of tomentose spots................................................................... 7

5 Body dorsally bicolor; head and pronotum purple, elytra blackish; pronotum without white tomentum in lateral impressions; size 8.5–12.2 mm; Vietnam (Vinh Phuc), Peninsular Malaysia, Singapore, Sumatra, Java, Borneo, Luzon; (habitus Fig. 1F aedeagus Fig. 2I).................................................................. A. raapi Kerremans, 1900

- Body dorsally concolor blue or black; pronotum with white narrow tomentum in lateral impressions.................... 6

6 Body blue; prosternal process subparallel; size 9.2–11 mm; New Guinea; (habitus Fig. 1B, aedeagus Fig. 2F)........................................................................................... A. indigaceus Deyrolle, 1864

- Body black with silky tinge; prosternal process dilated; size: 9–12.2 mm; Indonesia: Maluku; (habitus Fig. 2D, aedeagus Fig. 2L)................................................................................ A. vendibilis sp. nov.

7 Elytra with obvious humeral pair of tomentose spots; size 10.8–12.8 mm; Indonesia: Sulawesi; (habitus Fig. 1D)................................................................................................. A. puncak sp. nov.

- Elytra without humeral pair of tomentose spots.............................................................. 8

8 Top-most part of elytral apices glabrous; size 9.8–13.9 mm; Laos, Vietnam; (habitus Fig. 2A, aedeagus Fig. 2J).......................................................................................... A. rousselatae Baudon, 1968

- Top-most part of elytral apices with minute pubescent area..................................................... 9

9 Elytra brightly blue; size 9.5 mm; Papua New Guinea: North Solomons; (see Curletti, 2003, Fig. 16 as samuelsoni).................................................................................... A. samuelsonicus Curletti, 2006

- Elytra black......................................................................................... 10

10 Body smaller (6.6–10.6 mm); elytra with 1–2 pairs of unclear tomentose spots; head purple; exposed laterosternites without tomentose spots (dorsal view); Peninsular Malaysia, Sumatra, Borneo; (habitus Fig. 1E, aedeagus Fig. 2H)........................................................................................... A. purpurifrons Deyrolle, 1864

- Body larger (9–12.4 mm); elytra with 1–2 pairs of obvious tomentose spots; head dark-blue or black; exposed laterosternites with pair of tomentose spots (dorsal view); Bhutan, Northeastern India, Laos, Thailand, Vietnam; (habitus Fig. 1C, aedeagus Fig. 2G)......................................................................... A. morio Kerremans, 1895