A new genus and three new species of Neotropical Tanyproctini (Coleoptera: Scarabaeidae: Melolonthinae)
Author
Neita, Jhon Cesar
Author
Ocampo, Federico C.
text
Zootaxa
2012
3281
41
55
journal article
10.5281/zenodo.213516
fc75f873-c6d6-48eb-9dcd-383eb9ae8e23
1175-5326
213516
Eideria
Neita & Ocampo
, new genus
(
Figs. 1–29
)
Type
species
.
Eideria pentaphylla
Neita & Ocampo
,
new species
, here designated.
Description of male
.
Head
(
Fig. 1
): clypeus with apex round, margin reflexed. Labrum poorly developed, conical, not visible beyond clypeal margin (in dorsal view). Labium poorly developed, pentagonal; labial palpus with 2 palpomeres, palpomere 1 membranous, palpomere 2 sclerotized (
Fig. 5
). Maxilla with galea poorly developed, palpus long, with 4 palpomeres; palpomere 4 as long as 1–3 combined (
Fig. 6
). Mandible poorly developed (
Fig. 7
). Eye canthus strongly produced laterally, outer edge expanded in large, rounded projection. Antenna with 9 antennomeres, club large, subequal in length to antennomeres 2–4 combined (
Fig. 9a
).
Pronotum
(
Fig. 1
): convex, wider than long. Margins slightly rounded, with lateral bead; bead extended to lateral half of posterior margin. Anterior angles acute; posterior angles broadly rounded.
Elytra
(
Fig. 1
): convex, elongate, subparallel, completely covering dorsal surface of abdomen. Elytra with 4–8 striae.
Hind
wing
(
Fig. 8
): subcostal and radial vein well sclerotized, not reaching radial sector vein at wing apex; radial sector vein forked at apex; medial vein well developed; medial loop short; cubital vein slightly sclerotized apically from medial loop connection; anal veins 1, 2 not connected, not forming a basal cell.
Ve n te r
: prosternal process absent, coxae transverse. Mesosternum with sulcus on middle, surface punctate, setose; punctures small, dense, ocellate. Metasternum with the apex divergent, punctures ocellate, densely setose. Abdomen with 6 ventrites exposed; ventrite V longer than ventrite I-IV combined. Pygidium wider than long, concave, recumbent toward metacoxae. Surface with punctures strongly impressed, ocellate, setose.
Legs
: protibia with 3 teeth (
Fig. 10
a), protibial spur absent (
Fig. 10
b). Mesotibia with spine-like setae on external margin, mesotibial apex with 1 spur on inner margin (
Fig. 11
a–b). Metatibia with 2 spurs; spurs subcontiguous, on the inner edge (
Fig. 12
a–b). Protarsomeres, mesotarsomeres, and metatarsomeres 1.85 times longer than tibiae (
Figs. 10
a, 11a, and 12a). Tarsomeres 1 and 5 twice as long as 2–4 combined; tarsomeres 2–4 subequal; all tarsi with long, apical setae (
Figs. 10
a–12b). Tarsal claws bifurcated, symmetrical (
Fig. 13
).
Genitalia
(
Figs.14
a–b): parameres with a small carina on outer surface, outer surface setose; phallobase slender, with basal tegmen developed. spiculum gastrale developed (
Fig. 15
).
Description of female
. Most New World
Tanyproctini
present strong sexual dimorphism. Differences can be expressed in body length and width, color, size of antennae (smaller in females), and eyes (reduced in females). Female specimens are known for the following New World
Tanyproctini
genera:
Burmeisteriellus
Berg, 1868
;
Castanochilus
Ohaus, 1909
;
Lichniops
Gutiérrez, 1946
;
Lichniopsoides
Martínez, 1953
;
Myloxena
Berg, 1881
;
Myloxenoides
Martínez, 1975
, and
Ptyophis
Redtenbacher 1868
.
Eideria
females are larger than males; have lighter dorsal coloration of clypeus, pronotum, and elytra; and have reddish brown legs (
Figs. 2
,
4
).
Head
: color black; punctures setose, larger than on male (
Fig. 16
). Clypeus slightly parabolic (
Fig. 16
). Eye canthus well developed, with few setae; setae long, slender. Eyes poorly developed. Frontoclypeal suture well defined, complete, convex at middle.
Pronotum
: convex, wider than long at middle. Surface moderately punctate, punctures ocellate, moderate in size. Anterior angles rounded; posterior angles broadly rounded (
Fig. 17
).
Scutellum
: surface opaque, punctures moderately dense.
Elytra
: convex, elongate. Surface shiny, setose, densely punctate.
Hind
wings
: poorly developed, nonfunctional, reduced to a small lobe. Propygidium and pygidium not covered by elytra.
Pygidium
: not recumbent.
Venter
: prosternal process absent, slightly concave on sides. Abdomen, with 6 ventrites exposed medially, ventrite VI longer than ventrites III–V combined.
Legs
: protibia with 3 teeth; basal tooth small, dorsal surface with a line of setae from base to apex; protibial spur not developed (
Fig. 18
). Mesotibia with one spur (
Fig. 19
). Metatibia with two subcontiguous spurs (
Fig. 20
). Tarsi as long as tibiae (
Fig. 18–20
). Tarsal claws simple (
Fig. 21
).
Classification
. Neotropical
Tanyproctini
were reviewed by
Martínez (1975)
, who also provided a genus-level key to the tribe. Based on external morphology and male genitalia, we consider that
Eideria
belongs to the tribe
Tanyproctini
as it is currently defined.
Current classification of
Melolonthinae
and, in particular, the concepts currently used to diagnose Neotropical
Tanyproctini
and Macrodactilini, make difficult to characterize and even separate these two tribes. As a consequence of this, it is sometimes difficult to place new genera within these tribes.
Katovich (2008)
cited three synapomorphies for
Macrodactylini
: Fifth visible ventrite longer than fourth visible ventrite; propygidium lacking a complete suture between the ventrite and tergite (these characters are also found in other tribes in
Melolonthinae
); and metatibiae with one or two closely placed apical spurs, inserted below the tarsal articulation, so that the metatarsus moves past them (occasionally spurs are secondarily absent). According to
Katovich (2008)
, while none of these characters are unique, together they are unique to
Macrodactylini
.
According to our observations,
Macrodactylini
has the basal articulation condyle of the first metatarsomeres well developed, projecting above of the inner cuticle of metatibia (
Ancistrosoma
Curtis, 1835
;
Barybas
Blanchard, 1850
;
Ceraspis
LePeletier & Serville, 1828
;
Chariodema
Blanchard, 1850
;
Clavipalpus
Laporte, 1832
;
Dicrania
LePeletier & Serville, 1828
;
Gama
Blanchard, 1850
;
Isonychus
Mannerheim, 1829
;
Macrodactylus
Dejean, 1821
; and
Plectris
LePeletier & Serville, 1828
). In Neotropical
Tanyproctini
, the condyle is poorly developed.
Macrodactylini
species also have the metatibae with two adjacent spurs (or no spurs), a characters commonly used to diagnose this tribe. Some
Tanyproctini
genera also have two adjacent spurs on the external edge of metatibia (some species in
Acylochilus
Ohaus, 1909
;
Leuretra
Erichson, 1847
;
Myloxena
Berg, 1881
;
Myloxenoides
Martínez, 1975
; and
Puelchesia
Ocampo & Smith, 2006
), while other
Tanyproctini
genera such as;
Anahi
Martínez, 1958
;
Luispenaia
Martínez, 1972
; and
Burmeisteriellus
Berg, 1898
have the inner spur in the metatarsal apical notch and the outer spur on the external edge of metatibia; or
Diaphylla
Erichson, 1847
without spurs in the metatibia. The pygidium is strongly recumbent in Neotropical
Tanyproctini
and not strongly recumbent in
Macrodactylini
genera.
Sexual dimorphism in
Macrodactylini
is less evident than in most Neotropical
Tanyproctini
.
Macrodactylini
sexual dimorphism is generally expressed in the length and shape of antennal club, the form of the pygidium, and sometimes coloration, but these characters never reach the extreme morphological differences found in most Neotropical Tanyprocyini species. Sexual dimorphism in
Tanyproctini
is strongly expressed in characters such as body length and width, color, size of antennae (much smaller in females), eyes (reduced in females), and hind wings (reduced and nonfuctional in females).
Based on the above, we feel more confident placing
Eideria
within the tribe
Tanyproctini
.
Eideria
shares with other New World
Tanyproctini
genera the following character states: body elongate, slen- der, elytral margins subparallel; clypeus broadly rounded, recumbent; frontoclypeal suture developed and evident; mouthparts (labrum, mandibles, maxillae, labium) strongly reduced; pronotum convex, wider than long; legs long slender; protibia with three teeth; mesotibiae and metatibiae with transverse carinae developed. Six ventrites exposed medially; V ventrite longer than ventrites I–IV combined; males with pygidium strongly recumbent; male genitalia symmetrical, parameres slender.
Diagnosis
. Males of the genus
Eideria
are distinguished from all other Neotropical
Melolonthinae
by the following combination of characters: clypeus broadly rounded; labrum reduced, conical, not visible beyond clypeal margin (in dorsal view); antennae with 9 antennomeres, antennal club with 4–5 antennomeres (
Fig. 9a
); venter lacking prosternal process; metaesternum with apex divergent; pygidium recumbent toward metacoxae; protibial spur absent, mesotibia with 1 spur, metatibia with 2 spurs (
Figs.11
a–12b); spurs subcontiguous, both set below tarsal articulation; protarsomeres, mesotarsomeres, and metatarsomeres 1 and 5 subequal in length (1.8 times longer than wide) (
Figs. 10
a, 11a, 12a).
Eideria
is similar to
Luispenaia
and
Puelchesia
.
Luispenaia
has a prosternal process, but this is absent in
Puelchesia
and
Eideria
.
Luispenaia
has tubercles on dorsal tibial surface, but this surface is smooth in
Puelchesia
and
Eideria
.
Luispenaia
and
Puelchesia
have tibiae with spurs, one on protibia and two on mesotibia and metatibiae, while
Eideria
has no spur on protibia, one spur on mesotibia, and two spurs on metatibia.
Puelchesia
and
Eideria
have two adjacent spurs on the on the apex of the metatibia;
Luispenaia
has two separated spurs, one spur on the lateral margin and one within the apical notch of the metatibia (the notch that allows mobility of the tarsus back and forth). Tarsal claws are simple in
Puelchesia
,
but they are bifurcated in
Luispenaia
and
Eideria
.
The apex of metasternum is bifurcated in
Luispenaia
, and simple in
Puelchesia
and
Eideria
.
Puelchesia
has the hind wing with anal veins
V1 and V2
connected and forming a basal cell, in
Luispenaia
and
Eideria
anal veins
V1 and V2
are not connected and the basal cell is not present (
Fig. 8
).
Etymology
.
Eideria
is feminine in gender. We are pleased to name this genus after our friend and colleague Eider Ruiz-Manzanos, who unexpectedly passed away at a young age and who devoted her last years of research to the study of Neotropical
Tanyproctini
.