Larvae of the genus Eleodes (Coleoptera, Tenebrionidae): matrix-based descriptions, cladistic analysis, and key to late instars
Author
Smith, Aaron D.
Department of Biological Sciences, Northern Arizona University, PO Box 5640, Flagstaff, AZ, 86011 - 5640, USA
Author
Dornburg, Rebecca
School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ, 85287 - 4501, USA
Author
Wheeler, Quentin D.
SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210, USA
text
ZooKeys
2014
2014-06-12
415
217
268
http://dx.doi.org/10.3897/zookeys.415.5887
journal article
http://dx.doi.org/10.3897/zookeys.415.5887
1313-2970-415-217
287A4DC80EFC42C6AA55DBB4D7A3441B
6C204B3EFFF8FFF7FFE4FFF3FFC13468
578301
Eleodes Eschscholtz, 1829
Material examined.
Over 1,400 larval
Eleodes
specimens were examined for this study from 14
Eleodes
species. In addition, historical descriptions and
Eleodes
specimens for which the species could not be confirmed due to a lack of positive association between adults and larvae also conform to the generic description provided.
Description.
Integument strongly sclerotized, light tan to nearly black in color; setose, with hair-like setae throughout and spinose setae on legs and abdominal tergite IX. Thoracic and abdominal segments subcylindrical, surface coriaceous (
Figs 2A-D
,
3A-D
,
4A-C
,
5A-C
,
6A-C
).
Figure 2.
Dorsal habitus of four
Eleodes
species:
A
Eleodes (Caverneleodes) wheeleri
;
B
Eleodes (Eleodes) armatus
C
Eleodes (Eleodes) caudiferus
D
Eleodes (Eleodes) tribulus
. Scale bar = 5 mm.
Figure 3.
Dorsal habitus of four
Eleodes
species:
A
Eleodes (Litheleodes) extricatus
B
Eleodes (Melaneleodes) anthracinus
C
Eleodes (Melaneleodes) carbonarius
D
Eleodes (Tricheleodes) pilosus
. Scale bar = 5 mm.
Figure 4.
Lateral habitus of three
Eleodes
species:
A
Eleodes (Blapylis) nigropilosus
B
Eleodes (Caverneleodes) wheeleri
C
Eleodes (Eleodes) armatus
. Scale bar = 5 mm.
Figure 5.
Lateral habitus of three
Eleodes
species:
A
Eleodes (Eleodes) caudiferus
B
Eleodes (Eleodes) tribulus
C
Eleodes (Litheleodes) extricatus
. Scale bar = 5 mm.
Figure 6.
Lateral habitus of three
Eleodes
species:
A
Eleodes (Melaneleodes) anthracinus
B
Eleodes (Melaneleodes) carbonarius
C
Eleodes (Tricheleodes) pilosus
. Scale bar = 5 mm.
Head.
Prognathous or slightly declined (
Fig. 7A-C
), weakly dorsoventrally flattened, strongly constricted before occipital foramen. Epicranial stem one-fourth to one third head capsule length; frontal arms U-shaped or sinuate, occasionally obscured by sculpturing. Frons and dorsal portion of epicranial plates weakly to moderately rugose; punctate, punctures minute, lacking setae. Ventrolateral portions of epicranial plates setose; setae golden, erect; two stemmata present on each plate, pigmented spots often faded. Clypeus trapezoidal, often weakly transversely raised medially. Labrum with two transverse rows of six to fourteen erect setae present medially and subapically; anterior margin straight or weakly emarginate. Epipharynx (
Figs 8
,
9A-D
,
10A-D
) with stout spiniform setae along anterior margin, an anterior cluster of four to six variably arranged spinules, a subanterior transverse row of four small spinules subtended by two spinose setae and posterior cluster of six to eight small spinules; tormae symmetrical or asymmetrical. Mandible apex bidentate, mola concave. Ligula small, setation variable (
Fig. 11A-C
). Hypopharyngeal sclerome pentagonal or trapezoidal (
Fig. 12A-B
). Gula distinct, trapezoidal, widest in basal half. Antenna three segmented, cylindrical.
Figure 7.
Lateral habitus of the head and thoracic segments of three
Eleodes
species:
A
Eleodes (Melaneleodes) anthracinus
B
Eleodes (Litheleodes) extricatus
C
Eleodes (Promus) subnitens
. Scale bar = 5 mm.
Figure 8.
Eleodes (Melaneleodes) anthracinus
, epipharnyx. asp = anterior spines, msp = medial spines, mst = microsetae, pap = sensory papillae, tor = tormae. Scale bar = 1 mm.
Figure 9.
Epipharynges of four
Eleodes
species:
A
Eleodes (Melaneleodes) carbonarius
B
Eleodes (Eleodes) armatus
C
Eleodes (Eleodes) hispilabris
D
Eleodes (Eleodes) tribulus
. Scale bars = 1 mm.
Figure 10.
Epipharynges of four
Eleodes
species:
A
Eleodes (Litheleodes) extricatus
B
Eleodes (Promus) goryi
C
Eleodes (Promus) subnitens
D
Eleodes (Tricheleodes) pilosus
. Scale bars = 1 mm.
Figure 11.
Ligulas of three
Eleodes
species:
A
Eleodes (Melaneleodes) carbonarius
B
Eleodes (Eleodes) armatus
C
Eleodes (Promus) goryi
. Scale bars = 200
µm
.
Figure 12.
Hypopharyngeal scleromes of two
Eleodes
species:
A
Eleodes (Melaneleodes) carbonarius
B
Eleodes (Litheleodes) extricatus
. Scale bars = 200
µm
.
Thorax
.
Prothoracic tergum 1.2
x
or more length of meso- or metaterga (
Figs 2A-D
,
3A-D
); anterior transverse striated band present, generally darker than protergal disc; lateral margins with granulated band either distinct or barely visible (
Fig. 7A-C
). Posterior transverse striated band present on all thoracic tergites. Meso- and metathoracic tergites wider than long. Mesothoracic spiracle simple, ovate, approximately 1.5
x
size of abdominal spiracles; reduced metathoracic spiracle visible, less than one-fourth size of mesothoracic spiracle. Legs. Prothoracic leg slightly longer, much thicker than meso- and metathoracic legs; prothoracic tarsungulus strongly sclerotized, sickle-shaped; dorsal surface of prothoracic femur with faintly indicated basal sclerotized band; dorsal surface of prothoracic tibia slightly more sclerotized than ventral surface.
Abdomen.
Abdominal tergites and sternites I-VIII with transverse striated bands present along posterior margins. Abdominal sternite I setose (
Fig. 13A-B
). Abdominal segment IX (pygidium) triangular in dorsal view, gradually reflexed to apex, urogomphi absent, apical tooth present or absent (
Fig. 14A-B
); marginal row of socketed spines present around posterior two-thirds to one half of segment. Abdominal segment X located ventrally; pygopods short, subconical, each with erect setae.
Figure 13.
Abdominal sternites I and II for two
Eleodes
species:
A
Eleodes (Eleodes) caudiferus
B
Eleodes (Litheleodes) extricatus
. Scale bars = 1 mm.
Figure 14.
Pygidia of two
Eleodes
species:
A
Eleodes (Eleodes) hispilabris
B
Eleodes (Tricheleodes) pilosus
. Scale bar = 1 mm.
Variation.
Eleodes
larvae can vary greatly in pigmentation, size, number of spines on the legs and pygidium, and the overall degree of sclerotization. Characters in the matrix relating to general integument coloration (6, 24, 45, 46, 47, 69) can vary greatly between specimens depending on age of specimen, length of time since last instar, and preservation method. There may also be genetic variation, though specimens from our populations were generally homogeneous.
Diagnosis.
All known
Eleodes
larvae share the following combination of characters: head capsule weakly dorsoventrally flattened, strongly constricted before occipital foramen; prothoracic tergum 1.2
x
or more length of meso- or metaterga, anterior transverse striated band present, lateral margins with granulated band either distinct or barely visible; prothoracic leg slightly longer and much thicker than meso- and metathoracic legs; 8-38 socketed spines on the pygidial margin, pygopods short, subconical, each with erect setae. However, the known
Eleodes
larvae cannot yet be separated from other
Amphidorini
larvae due to a lack of specimens.