Agyrtodes Portevin

Seago, Ainsley E., 2009, Revision Of Agyrtodes Portevin (Coleoptera: Leiodidae), The Coleopterists Bulletin (mo 7) 63, pp. 1-73 : 3-11

publication ID	https://doi.org/ 10.1649/0010-065x-63.sp7.1
publication LSID	lsid:zoobank.org:pub:B58B2216-0CFA-41C6-8141-7024E65ECF85
persistent identifier	https://treatment.plazi.org/id/039887BA-FFE5-C047-9280-8188ED9F917A
treatment provided by	Carolina
scientific name	Agyrtodes Portevin
status

Treatment

Agyrtodes Portevin View in CoL

Agyrtodes Portevin 1907: 75 View in CoL ; type species: A. ovatus Portevin, 1917 View in CoL . Jeannel (1936: 103); Szymczakowski (1966: 9, 1973: 94); Zwick (1979: 5); Newton (1998: 78); Seago (2005: 2).

Ragytes Portevin 1914: 196 View in CoL ; type species: R. luteipes Portevin 1914 View in CoL (by monotypy). Jeannel (1936: 107) [synonymy with Agyrtodes View in CoL ].

Etymology. In his description of the genus, Portevin did not explain his choice of name for the genus; it is likely intended to reflect this group’s similarity to Agyrtes Frölich , a broadly distributed holarctic genus in the family Agyrtidae . Jeannel (1936) states that Portevin believed that the specimens he described as Agyrtodes belonged to the tribe Agyrtini , which was then considered one of two tribes in the silphid subfamily Agyrtinae . Newton (1997) removed these two tribes from the Silphidae and placed them in a separate family, Agyrtidae .

Taxonomic History. Agyrtodes has been at least partially reviewed by Jeannel (1936), Szymczakowski (1966), and Zwick (1979). Jeannel (1936) synonymized several New Zealand species described by Broun and moved several Broun and Blackburn species (from Mesocolon and Cholevomorpha , respectively) to Agyrtodes . Szymczakowski (1966) redescribed the Australian and New Zealand species and provided a key. Zwick (1979) reviewed the southeastern Australian Agyrtodes (including only species from Victoria, Tasmania, and portions of the ACT), and described two new species. Jeannel’s synonomies were rebutted by Newton (1998), who also synonymized A. varius (Jeannel) with A. nebulosus (Broun) and noted the existence of several undescribed species from New Zealand and Australia.

Diagnostic Characteristics. Portevin (1907) distinguished Agyrtodes (then monotypic) by the following characters: dorsum pubescent, elytra transversely striolate, mesosternum carinate, antennal club interrupted, and male anterior tarsus with first segment expanded. The first three characters supplied by Portevin remain effectively diagnostic of Agyrtodes as it is defined here; the lack of an occipital carina on the head distinguishes Agyrtodes and all other camiarines from the similarly pubescent and often transversely striolate members of Cholevinae . Most Agyrtodes may also be recognized by the presence of a ‘‘spore-brush’’ on the lacinia ( Fig. 30 View Figs , sb), a distinct antennal club with segment 8 subquadrate (rarely wider than long), and a compact, ovoid body shape in dorsal view. In addition to these characters, all species of Agyrtodes that bear color patterns have a parallel pattern of dorsal vestiture, with dark brown setae over darker regions of the integument and light gold to silver setae on lighter regions. This type of setal coloration also occurs in the agyrtodine genera Chiliopelates and Zearagytodes , which can be distinguished from Agyrtodes by their narrower body shapes and (in the latter) extremely long, slender antennae and a narrow, muzzle-like frons and clypeus. Setal coloration is critical to recognition of color patterns in teneral individuals and older dried specimens of Agyrtodes , which tend to fade; several species also exhibit considerable variation in the darkness of the integument.

The following characters are most useful in distinguishing between species of Agyrtodes : color pattern defined by integument color and/or dorsal vestiture; shape of the male genitalia (median lobe, parameres, and genital capsule); coloration, shape and relative proportions of the antennal segments; proportions of the maxillary palpomeres; punctation of the head and pronotum; and the presence or absence of an epistomal suture.

Absence of the epistomal suture was used as a diagnostic character for Agyrtodes by Jeannel (1936) and Sczymczakowski (1966); however, the epistomal suture is present (albeit sometimes indistinct in uncleared specimens) in the majority of species.

Adult Description. Body size small to medium-sized among Agyrtodini (1.6– 3.5 mm), with hind wings and eyes always present. Body shape somewhat variable, ovate or ovoid, always convex, dorsum with long, abundant pubescence. Integument brown, elytra sometimes patterned with lighter spots or transverse fasciae, which seem to fade in older individuals. Color patterns (when present) of varying shades of brown, emphasized by correspondingly colored dorsal pubescence. Head covered with fine punctures, punctation of pronotum extremely fine, nearly imperceptible in certain species.

Head ( Fig. 22 View Figs ) without occipital carina; epistomal suture present or absent, with or without stem. Labrum short and transverse, subrectangular, slightly cleft apically. Antennae ( Figs. 22 View Figs , 38–57 View Figs View Figs ) with broad scape and pedicel, scape frequently arched, ‘‘stem’’ (segments 3–6) elongate and slender, with loose 5- segmented club. Club segments longer than wide in most species; in a few species antennal segments 8 and/or 10 transverse, with segment 8 frequently globular to subquadrate. Antennal segments 2–6, 8, and 9 each encircled by two irregularly transverse rows of long, erect setae projecting nearly perpendicularly to long axis of antenna; segments 1, 7, 10, and 11 with three such rows. Mandibles ( Fig. 29 View Figs ) stout, curving externally, dens blunt, mola broad, with loose membranous prostheca on internal face. Maxillae ( Fig. 30 View Figs ) elongate, galea slender, crowned with apical brush of fine setae; lacinia broad, with articulated, apical ‘‘spore-

Figs. 1–20. Agyrtodes spp. 1 ) A. ovatus ; 2) A. crassus ; 3) A. variegatus ; 4) A. decoratus ; 5) A. flaviceps , new sp.; 6) A. monteithi , new sp.; 7) A. newtoni , new sp.; 8) A. tasmanicus ; 9) A. eucalypti ; 10) A. globosus , new sp.; 11) A. atropos ; 12) A. koebelei ; 13) A. variabilis , new sp.; 14) A. bicolor ; 15) A. nebulosus ; 16) A. lescheni , new sp.; 17) A. labralis ; 18) A. monticola ; 19) A. nemoralis ; 20) A. hunuensis.

brush’’ of short, densely packed spines. Maxillary palpi slender and elongate, apical palpomere slender, tapering, longer than preceding segments (except A. crassus ). Labium with ligula ( Fig. 31 View Figs ) membranous, with varying numbers of digitiform sensillae on distal margin and small 3-segmented palpi bearing sensory

aa anterior apophysis of male genital segment

cx coxa

cxt coxite

dn dens

ds digitiform sensilla

ep endophallus

epln epipleuron

f furca

fst styli (of female genitalia)

gl galea

hp hypomeron

lc lacinia

lp labial palp

ma mola

mb membranous region of ovipositor

mc mesosternal carina

md mandible

ml median lobe

msepm mesepimeron

mseps mesepisternum

mt mentum

mtepm metepimeron

mteps metepisternum

mx maxilla

pg palpiger

pls pleurosternite 5 sternum IX

pm paramere

pn penis

pt prostheca

sb spore-brush

ssi sutural strial impression

st sternum

sty stylus

t tergum

ts terminal seta

setae or minute fingerlike sensillae. Mentum trapezoidal, narrowed distally, slightly wider than long; submentum large, bluntly triangular, punctate. Gula reduced to small triangular area adjacent to cervix, constricted between postgenae. Cervical region ventrally produced into short, collarlike rim; cervical sclerites present, slender, flattened and curving.

Pronotum generally transverse, widest toward posterior margin. Hind angles sometimes slightly acute and projecting, always blunt. Pronotal microsculpture consisting of shallow punctures, very fine shallow whorls, shining in some species. Elytra ( Fig. 21 View Figs ) with transverse strigae lined with small, stiff hairs, arranged in roughly parallel rows that slope towards the suture. Sutural stria present, effaced basally; longitudinal striae absent from disc or represented by very faint longitudinal impressions. Elytral apex bluntly pointed in both sexes. Epipleura concave, shining, laterally delimited by pronounced longitudinal bead; epipleural carinae armed with single row of long, erect setae projecting laterad. Flight wings ( Fig. 26 View Figs ) present, never reduced, with typical agyrtodine wing ‘‘venation’’ of weakly sclerotized vein remnants.

Prosternum ( Fig. 23 View Figs ) short and transverse, not extending beyond procoxae. Hypomeron broad, smooth, without visible glandular openings. Procoxal cavities narrowly separated by prosternal process and closed internally by blunt notal process. Mesepimeron bluntly rectangular, extending to lateral margins of mesocoxal cavities. Mesosternum ( Fig. 24 View Figs ) (including mesoventrite and mesepisternum) divided anteriorly by complete transverse suture. Mesepisterna small, triangular, separated from mesoventrite by two distinct, roughly perpendicular sutures, lateral regions of transverse suture, and sternopleural suture. Mesosternum with well-developed median carina, usually effaced in anterior quarter, dramatically elevated along median line at subanterior transverse suture, and highest between mesocoxae. Mesocoxal separation formed anteriorly by mesosternal process and posteriorly by non-carinate median metasternal projection. Mesosternal microsculpture of shallow, whorled strigulae, most pronounced laterally. Metepisterna extending from lateral margins of mesocoxal cavities to metacoxal cavities, elongate, approximately parallel-sided, separated from metasternum by suture; metepimera smaller, attenuate at both ends, articulating with metacoxal cavities but not with mesocoxae. Metasternum ( Fig. 24 View Figs ) broad, bulging, not carinate; covered with even array of deep punctures bearing minute setae, sometimes with raised isodiametric sculpticells. Metacoxal separation formed anteriorly by short posterior projection of metasternum (arising from base of metathoracic discrimen/ metakatepisternum), posteriorly by excavate sternum III (5 first visible abdominal ventrite).

Abdominal sterna ( Fig. 25 View Figs ) broad, strongly sclerotized, laterally inflexed, with carinate ‘‘corners’’. In males, sternum VII (5 fifth abdominal ventrite) with distal emargination of varying depth, male sternum VIII notched or cleft; both simple and distally convex in females. Female sternum VIII with small, internal median apophysis ventrally.

Abdomal terga narrow, transverse, weakly sclerotized; terga IV–VII with broad, oval, laterally situated patches of minute spines, presumably used in wing folding; tergum VII also with shallow strip of extremely small ‘‘combs’’ of short teeth along posterior margin (similar to those shown in Newton 1997, Fig. 26 View Figs ).

Procoxae globular to conical in shape, strongly projecting ventrally. Mesocoxae ovate, rounded but not projecting. Metacoxae flattened, elongate and triangular, tapering laterally. Legs ( Figs. 27–28 View Figs ) with apical armature of tibiae typical of Agyrtodini : two parallel, external spine rows along tibiae; protibiae with apical cluster of several large spines separated by ‘‘comb’’ of smaller spines; large apical spine of hind tibiae of variable length, never as long as first tarsomere. Anterior tibia shorter than other tibiae, straight, narrow basally, expanded apically; median tibiae straight or slightly arched, hind tibiae straight. All femora short, flattened, with paired apical flanges and posterioventral grooves for reception of tibiae. Tarsi 5-5-5. Protarsi of both sexes with segment 5 longer than segments 2–4 combined, except in A. koebelei , A. variabilis Seago , new species, and A. monteithi Seago , new species which have protarsomere 5 shorter than 2–4 combined. Tarsal claws simple in both sexes.

Male genitalia ( Figs. 32–34 View Figs ) with genital segment complete, sometimes elongate and laterally compressed but never tubular, formed by two apically setose pleurosternites and sparsely pubescent tergite. Pleurosternites of genital segment ( Figs. 33 View Figs , 58–77 View Figs View Figs ) fused basally to form anterior apophysis; sternum X, when present, appears as small, proximally attenuate diamond-shaped sclerite fused internally to ventral junction of pleurosternites. Aedeagus ( Figs. 34 View Figs , 78–97 View Figs View Figs ) simple, median lobe straight and symmetrical, penis shorter than or as long as parameres, sometimes curved or faintly lobed apically. Parameres large, flattened, rarely slender, armed on internal faces with many short or long setae and/or spinelike projections. Basal piece cylindrical, well-developed, as long or longer than penis (i.e., region of median lobe posterior to articulation of parameres). Endophallus with one or more longitudinal clusters of small spines in most species, sometimes with large, curving, fang-like sclerites (e.g., Figs. 89–90 View Figs ); small spine clusters absent in koebelei group of northern Queensland.

Female genitalia ( Figs. 35–37 View Figs ) with paired coxites and styli, each stylus bearing long terminal seta; coxite always well over twice as long as stylus. Internal portion of female reproductive tract consisting primarily of membranous, eversible ovipositor and large membranous bursa, apical portion of bursa sometimes weakly sclerotized into spermatheca-like structure ( Figs. 36, 37 View Figs ). Internal sclerite(s), when present, asymmetrical, bearing no resemblance to typical globular or tubular spermatheca present in many derived leiodids (e.g., Agathidiini , see Wheeler and Miller (2005), Fig. 36 View Figs ).

Non-genitalic sexual dimorphism apparent in protarsi ( Fig. 28 View Figs ) and abdominal sterna VII–VIII. Males with first three protarsomeres dilated to varying degrees. Mesotarsi simple in both sexes, with exception of expanded mesotarsal segments of male A. crassus , A. koebeli, and A. variabilis , and weakly bent first mesotarsomere of male A. nebulosus . Males of A. nebulosus (Broun) and A. lescheni Seago , new species with short, blunt tooth on mesofemora and long, stout subapical spur on metafemora. Male abdominal sternum VII clearly convex and slightly emarginate, VIII transverse and deeply notched; female sternum VII complete, weakly convex, sternum VIII transverse, arched, with complete margin.