Attavicinus Philips and Bell, 2008

Philips, T. Keith & Bell, Karen L., 2008, Attavicinus, a New Generic Name for the Myrmecophilous Dung Beetle Liatongus monstrosus (Scarabaeidae: Scarabaeinae), The Coleopterists Bulletin 62 (1), pp. 67-81 : 67-81

Attavicinus Philips and Bell , new genus

( Figs. 1–16 )

Type species: Oniticellus montrosus Bates, 1887 .

Redescription. Habitus. Body robust ( Figs. 1–2 ), dark in color.

Head with clypeus broadly rounded; external genal margin broadly rounded, posteriorly abruptly angled inward at eye; eye small; female with more pronounced armature consisting of anterior transverse ridge and basal protuberances, male with only basal protuberance. Antennae ( Fig. 3 ) with eight segments, last three lamellate, vesicle or cavity present in antennomeres 7 and 8. Epipharynx ( Fig. 4 ) with apex truncate, anterior edge medially with distinct setal tuft, second tuft just posterior with relatively few coarse setae, lateral (setal) combs with setal insertion points forming a curved line, remaining ventral surface with relatively evenly scattered fine setae. Mandibles ( Fig. 5, 6 ) with apex relatively sharply acute. Maxillary palp ( Fig. 7 ) four-segmented, first palpomere shortest, fourth nearly as long as previous three segments combined; galea broad, wider than long, scoop-like, lacinia much smaller. Labial palp ( Fig. 8 ) threesegmented, second palpomere enlarged, third strongly reduced, barely visible; mentum transverse, anteriorly with shallow notch sharply emarginate medially, laterally with small notch, surface hirsute, medially smooth and impunctate; anterior declivous region broad, triangular. Eye completely divided by canthus.

Pronotum ( Figs. 1–2 ) laterally straight-edged, broadening anteriorly, protruding ridges on either side of middle, more pronounced sculpture on female compared to male. Depressed at middle, small slight oval depression at posterior margin opposite scutellum, laterally with shiny smooth depression at anterolateral angles. Scutellum ( Fig. 14 ) with visible portion triangular in shape, short and broad, apex narrowly rounded, parabolic in shape.

Elytra ( Fig. 9 ) with surface uneven, raised towards anterior on sides. Suture depressed anteriorly and raised posteriorly. Each elytron wih seven visible striae, each consisting of a single shallow groove. Hind wings ( Fig. 10 ) fully developed, pigmented throughout; AA vein lacking remnant cross vein proximally, MP vein present, long in length, pigment patch near apical 1/3 present and distal edge emarginated and not strongly defined, anal region large, well developed, lacking posterior notch, jugal and AP veins both present, MP vein near posterior margin of wing distinctly, strongly curved, RA vein greatly extended along apical margin, ending near posterior margin, AA vein posteriorly forming cell partially closed, extending on both sides at proximal apex near middle.

Legs robust and stout; tarsi distinct, strongly developed, each with five short tarsomeres. Protibiae with four teeth, apical three strongly developed, basal tooth distinct but weakly projecting. Meso- and metatibia gradually expanding in basal

L, greatly expanded at apical J, mesotibial apex with two spurs, pro- and metatibia each with a single spur.

Ventral surface with prosternum nearly equal in width to procoxal width, distinctly longer towards lateral margin; mesosternum ( Fig. 15 ) with small lanceshaped ventral projection on anterior margin at middle, hidden in intact specimens; metepisternum subtriangular, broad anteriorly, narrowing to a point posteriorly. Abdominal ventrites 3–5 similar in length, shorter in middle and longer laterally and curved; ventrite 2 is 1.5 times the length of ventrites 3–5 at the 70 middle, similar length laterally and straight; ventrite 1 longest. Propygidium ( Figs. 11, 12 ) indistinct from pygidium, shorter than ventrites 1–5, with slight transverse groove anteriorly; pygidium ( Figs. 11, 12 ) broadly pointed.

Male genitalia ( Fig. 13 ) broad; parameres less than half the length of basal piece, apex blunt, ventromedially with small tooth, paramere position relative to basal piece oblique.

Etymology. This new generic name is derived from the host ant genus Atta together with the Latin ‘‘vicini’’ that means neighboring or near, in reference to the association with the debris piles of leaf-cutter ants. The gender is masculine.

Comments. This genus includes a single species found only in Jalisco and Michoacán, Mexico ( Fig. 16 ). Adults and larvae can be found within or under attine ant nest debris piles where breeding occurs .

Figures

Fig. 1. Dorsal habitus of Attavicinus monstrosus, female.

Fig. 2. Dorsal habitus of Attavicinus monstrosus, male, anterior half.

Figs. 3–8. Attavicinus monstrosus head structures. Scale bars equal 0.5 mm. 3) Antenna; 4) Epipharynx, ventral; 5) Mandible, ventral; 6) Mandible, dorsal; 7) Maxillae, dorsal and ventral views (scale bar 5 0.5 mm); 8) Labium, ventral.

Figs. 9–10. Attavicinus monstrosus elytron and wing. Scale bars equal 2.0 mm. 9) Elytron; 10) Wing.

Figs. 11–15. Attavicinus monstrosus structural features. Scale bars equal 0.5 mm. 11) Pygidium and propygidium, male; 12) Pygidium and propygidium, female; 13) Male genitalia, lateral view; 14) Mesoscutum-scutellum; 15) Ventral surface of mesoventrite, metaventrite and leg bases with right metaleg removed.

Fig. 16. Distribution records of Attavicinus monstrosus.