Lichniini, Burmeister, 1844

Hawkins, Shauna Joy, 2006, A revision of the Chilean tribe Lichniini Burmeister, 1844 (Coleoptera: Scarabaeidae: Melolonthinae), Zootaxa 1266 (1), pp. 1-63 : 17

Key to genera and species of Lichniini

Males and females are distinguished in the following manner: In the genus Lichnia , the male protibia is slender ( Fig. 3a ), whereas the female protibia is broader for its entire length ( Fig. 3b ). In the genus Arctodium , the male tibial apex is modified into a long, pointed spine ( Figs. 8a–c ), whereas the female tibial apex forms only a short, blunt spine ( Fig. 8d ).

1. Galea at least 1/3 body length ( Figs. 5b , 7b ). Mandible rounded, without apical teeth ( Fig. 6b )......................................................................................... (5) Lichnia Erichson

1´. Galea length less than 1/3 body length ( Figs. 5a , 7a ). Mandible dentate, with 2 apical teeth ( Fig. 6a ) .........................................................................(2) Arctodium Burmeister

2. Eye canthus with fringe of long, pale setae ................... Arctodium planum (Blanchard)

2´. Eye canthus with fringe of long, dark setae .................................................................. 3

3. Body length from apex of pronotum to apex of pygidium 5.0– 6.5 mm. Male metatibia with apical spine shorter than adjacent metatibial spur ( Fig. 8b ).................................... ........................................................................ Arctodium mahdii Hawkins , new species

3´. Body length from apex of pronotum to apex of pygidium greater than 7.0 mm. Male metatibia with apical spine subequal to or longer than adjacent metatibial spur ( Figs. 8a, 8c ) ........................................................................................................................... 4

4. Elytra as long as wide. Setae of posterior leg dark brown or black, never pale.............. ........................................................................................ Arctodium discolor (Erichson)

4´. Elytra longer than wide. Setae of posterior leg variable, but never black....................... ....................................................................................... Arctodium vulpinum (Erichson)

5. Antennal club of males shorter than segments 1–6 ( Fig. 4b ). Occurs in Region IV (Coquimbo) ( Fig. 10 ) .......................................................... Lichnia gallardoi Gutiérrez

5´. Antennal club of males longer than segments 1–6 combined ( Fig. 4a ). Occurs in Region V (Valparaíso) to Region VII (Maule) ( Fig. 10 ) ........ Lichnia limbata Erichson

Figures

FIGURES 3a–b. Dorsal view of foreleg of Lichnia limbata showing sexual dimorphism in male (a) and female (b).

FIGURES 4a–c. Dorsal view of antenna showing length of club. a) Lichnia limbata male; b) L. limbata female; c) Arctodium mahdii male.

FIGURES 5a–b. Dorsal view of maxilla showing length of galea. a) Arctodium discolor; b) Lichnia limbata.

FIGURES 6a–b. Dorsal view of labrum and mandibles showing form of the mandibles (a) dentate, Arctodium vulpinum or (b) rounded, Lichnia limbata.

FIGURES 7a–b. Lateral view of beetles showing length of galea. a) Arctodium vulpinum; b) Lichnia limbata.

FIGURES 8a–d. Metatibial apex showing apical spine (arrow) and adjacent spur. a) Arctodium planum male; b) A. mahdii male; c) A. vulpinum male; d) A. vulpinum female.

FIGURE 10. Map of central Chile showing distribution of Lichnia gallardoi and L. limbata.