Systematics, Distribution, And Host Specificity Of Edrabius Fauvel

13 Pages·1996·5.1 MB·

by  J S Ashe

PROCEEDINGS OFTHE BIOLOGICAL SOCIETY OF WASfflNGTON
109(4):731-743. 1996
Systematics, distribution, and host specificity of Edrabius Fauvel
(Insecta: Coleoptera: Staphylinidae)
James S. Ashe, Robert M. Timm, and Milton H. Gallardo
(JSA) Division of Entomology, Natural History Museum, Snow Hall, University of Kansas,
Lawrence, Kansas 66045, U.S.A.; (RJMT) Division of Mammals, Natural History Museum,
Dyche Hall, University of Kansas, Lawrence, Kansas 66045-2454, U.S.A.;
(MHG) Instituto de Ecologia y Evolucion, Universidad Austral de Chile,
Casilla 567, Valdivia, Chile
—
Abstract. Systematics, distribution, and host relations of the amblyopinine
genus Edrabius (Coleoptera: Staphylinidae) are reviewed. Herein, werecognize
11 species in the genus Edrabius, all of which are obligate associates ofSouth
American caviomorph rodents of the families Caviidae, Ctenomyidae, and Oc-
todontidae (Mammalia: Rodentia), and restricted to the southern cone of the
continent. Three new species are described: Edrabius grandis (host: Ctenomys
coyhaiquensis and C. haigi); Edrabiusaustralis (host: Ctenomysmaulinusmau-
linus); and Edrabius chilensiformis (host: Octodon degus). New distribution
and host records are given for E. alticolus Seevers, E. argentinus Seevers, E.
chilensis Scheerpeltz, E. peruanus Seevers, E. philippianus Fauvel, and E.
weiseri Seevers. Occurrence of Edrabius on octodontid rodents is reported for
the first time {E. chilensis from Aconaemys and E. chilensiformis from Octo-
don). The genus Edrabius was formerly known to occur in association with
various species of Ctenomys, with the exception of one species, E. kuscheli,
associated w—ith Galea musteloides (Caviidae).
Resumen. Se presenta una revision de la sistematica, la distribucion y las
relaciones de los hospederos de los amblyopininos del genero Edrabius (Co-
leoptera: Staphylinidae). Se reconocen 11 especies de Edrabius, todas parasitos
obligados de roedores caviomorfos sudamericanos de las familias Caviidae,
Ctenomyidae y Octodontidae (Mammalia: Rodentia). Se describen tres nuevas
especies: Edrabius grandis, hospedador: Ctenomys haigi); Edrabius australis,
hospedador: Ctenomys maulinus maulinus); y Edrabius chilensiformis, hospe-
dador: Octodon degus). Se entregan nuevos registros distribucionales y de hos-
pederos para E. alticolus Seevers, E. argentinus Seevers, E. chilensis Scheer-
peltz, E. peruanus Seevers, E. philippianus Fauvel y E. weiseri Seevers. Por
primera vez se reporta la presencia de Edrabius en roedores octodontidos {E.
chilensis en Aconaemys y E. chilensiformis en Octodon). El genero Edrabius
anteriormente se conocia solamente asociado a diferentes especies de Cteno-
mys, con laexcepcion de unaespecie, E. kuscheli, asociadaa Galeamusteloides
(Caviidae).
Perhaps the most interesting and enig- are unique members of the family Staphy-
matic of all insect-vertebrate interactions linidae because oftheir obligate association
are those of rove beetles of the tribe Am- with mammals; most of the 40,000 de-
blyopinini (Coleoptera: Staphylinidae) and scribed species of staphylinids are free-liv-
their mammal hosts. Amblyopinine beetles ing predators (Ashe & Timm 1987b). All
732 PROCEEDINGS OFTHE BIOLOGICAL SOCIETY OFWASHINGTON
known species of amblyopinines have been blyopinine genera is Edrabius. Currently,
most often found attached to the fur of eight species of Edrabius are known from
mammahan hosts or in the hosts' nests. Six southern Peru, Argentina, and Chile. These
genera and more than 55 species have been are: E. alticolus Seevers; E. argentinus
described in the tribe Amblyopinini; five Seevers; E. chilensis Scheerpeltz; E. kus-
genera are restricted to the Neotropical re- cheli Scheerpeltz; E. pearsoni Seevers; E.
gion and one is found in the Austrahan re- peruanus Seevers; E. philippianus Fauvel;
gion (Ashe & Timm 1988). Those restricted and E. weiseri Seevers. Of the species of
to the Neotropical region include: Ambly- Edrabius currently recognized, most occur
opinodes Seevers, Amblyopinus Solsky, on species of Ctenomys (Rodentia: Cteno-
Chilamblyopinus Ashe and Timm, Edrabius myidae), the tuco-tucos. However, in this
Fauvel, and Megamblyopinus Seevers; a paper we also report their occurrence on
single monotypic genus, Myotyphlus Fau- two additional genera of rodents, Aconae-
vel, is restricted to Australia and Tasmania mys and Octodon (Octodontidae). Cteno-
(Ashe & Timm 1988, 1995; Seevers 1944, myids and octodontids are caviomorph ro-
1955). dents that are found throughout southern
Amblyopinines were, until recently, be- South America. They occur in Argentina,
lieved to be obligate, blood-feeding ecto- Chile, southern Bolivia, and Peru and range
m
parasites. However, the Central American in elevation from sea level to 4700
&
Amblyopinus have a mutualistic relation- (Mares Ojeda 1982).
ship with their hosts rather than a parasitic Little information is available about the
one, and the conclusion that other ambly- life history or habits of the species of Ed-
opinines are parasitic is not supported by rabius, or about the nature of the beetle-
available evidence. Beetles living on vari- mammal interaction. Fauvel (1900) report-
ous rodents that have different nesting bi- ed the observations of Philippi that adults
ologies show significantly different behav- and larvae of Edrabius philippianus were
iors, and nesting biology of the hosts un- found around the anus ofa species of Cten-
doubtedly played a major role in the evo- omys and caused damage to the skin. Fau-
lution of this mutualistic relationship (Ashe vel received adult beetles that he subse-
& Timm 1987a, 1987b, 1988; Timm & quently described, but he did not mention
Ashe 1987, 1988, 1989). the larvae in his description, and he may
Hosts ofamblyopinines are primarily cri- not have actually receivedthem. Therehave
cetine and caviomorph rodents and South been no subsequent reports of amblyopi-
American marsupials. The evolution ofthis nine larvae on any host, although hundreds
association is exceptionally interesting, of mammals carrying adult amblyopinines
both in terms of the ecology, evolution and have been examined. Timm & Ashe (1989)
biogeography of the beetles themselves, described larval Edrabius that were found
and also of the mammals with which they in the nest of Ctenomys in Chile.
are associated. Members ofeach amblyopi- In this paper we: describe three new spe-
nine species are host specific, and members cies of Edrabius; review previously pub-
of the genera and intergeneric higher taxa lished information aboutEdrabius; andpro-
have a tendency to be associated with apar- vide new information on host and geo-
ticular group of mammals. Our concerted graphic distributions of Edrabius.
field efforts in recent years have uncovered
a high degree of host specificity in these Materials and Methods
rather large, active beetles (Ashe & Timm
1987a, 1995; Timm & Ashe 1987, and see Recent field work in Chile by one of us
below). (MHG) as part of his ongoing research on
One ofthe mostpoorly known ofthe am- the systematics and biogeography of Cten-
VOLUME 109, NUMBER4 733
omys, as well as that of other field workers University of California, Berkeley, Califor-
provide significant new information about, nia (MVZ).
and specimens of, Edrabius. The new ma-
terial prompted us to review the systematic Edrabius grandis, new species
status of all the species of Edrabius in Ar- Figs. 1-3
gentina, Bolivia, Chile, and Peru. —
In the course of this study, we examined Description. Length 9.0-10.5 mm.
the types and dissected aedeagi of all de- Uniformly light reddish-brown. Head shape
scribed species of Edrabius except E. phi- variable, small males and females with lat-
lippianus. According to Seevers (1955) the eral margins tapered uniformly from round-
holotype, and only known specimen, of E. ed posterior angles to front, heads of larger
philippianus is a female. He gives a de- males with lateral margins inflated and
tailed description of this specimen, includ- broadly rounded in posterior half (Fig. 1);
ing illustrations of distinctive pronotal fea- integument of head with dense, prominent,
tures. None of the species described here small-meshed, isodiametric microsculpture,
match the description of E. philippianus surface not strongly shining; withoutmicro-
given by Seevers. We also examined the punctures; microsetae on lateral margins
specimens that Scheerpeltz (1957) identi- behind eye very small and sparsely distrib-
fied as E. philippianus and that he used in uted. Antenna (Fig. 2) longer than head and
his comparisons with other species. We are pronotum together, article 2 slightly longer
convinced that these specimens are incor- than, or subequal to, article 3, article 4
rectly identified. They do not have the dis- slightly elongate; article 5 quadrate to
slightly elongate; articles 6-10 slightly to
tinctive pronotal shape that Seevers (1955)
described for E. philippianus, and other de- moderately elongate. Pronotum (Fig. 1),
moderately transverse, about 1.5-1.6 times
scribed features also do not fit Scheerpeltz's
as wide as long; without postero-lateral
specimens very well (though these are more
macroseta; microsetae on antero-lateral
qualitative and less distinctive). In addition,
margins very small and sparsely distributed,
all of Scheerpeltz's specimens are from Ar-
microsetae extended from near middle of
gentina, whereas the type ofE. philippianus
lateral margin ofpronotum to antero-lateral
is from Antofagasta, in the Atacama Desert
angles and very sparsely along lateral third
of Chile.
of anterior margin; integument with dense,
Specimens ofEdrabius examined are de-
prominent, small-meshed, isodiametric mi-
posited in: Instituto de Ecologia y Evolu- crosculpture, sculpticells more prominent
cion, Universidad Austral de Chile, Valdi-
laterally than medially, surface not strongly
via, Chile (lEEUACH); Field Museum of shining (except in specimens in which the
Natural History, Chicago, Illinois (FMNH); microsculpture has been eroded away due
Snow Entomological Museum, University to abrasion); surface without micropunctu-
of Kansas, Lawrence (KSEM); and Natur- res. Elytra with very fine, widely dispersed,
historisches Museum Wien, Vienna, Austria golden-yellow microsetae, punctures very
(NHMW). The mammal hosts are deposited small. Abdomen uniformly covered with
in: Instituto de Ecologia y Evolucion, Univ- silky vestiture of moderately dense, very
ersidad Austral de Chile, Valdivia, Chile fine, yell—owish microsetae.
(IEEUACH); American Museum ofNatural Male. Posterior margin tergum VIII
History, New York (AMNH); Field Muse- emarginate. Posterior margin of sternum
um of Natural History (FMNH); Museum VIII broadly and evenly emarginate, maxi-
of Southwestern Biology, University of mum depth ofemargination about 0.5 times
New Mexico, Albuquerque, New Mexico width of emargination.
—
(MSB); Museum of Vertebrate Zoology, Aedeagus. As in Fig. 3.
734 PROCEEDINGS OFTHE BIOLOGICAL SOCIETY OFWASHINGTON
1
Figs. 1-3. Edrabius grandis n. sp. L Head and prothorax, dorsal (scale = 1.0 mm); 2. Antenna (scale
1.0 mm); 3. Apex ofaedeagus, lateral (scale = 0.1 mm).
VOLUME 109, NUMBER4 735
—
Holotype. Male, with labels as follows: obsolete to absent postero-medially, sur-
"Argentina: Prov. Rio Negro; 13 km WSW face strongly shining; micropunctures ex-
Comallo, el. 1150 m, 15 Nov 1987, A. K. tremely fine and inconspicuous; microsetae
and O. P. Pearson #OPP 7435, ex. Cteno- on lateral margins of head behind eye
mys haigi (MVZ 175156)." "HOLOTYPE, sparse to moderate in size and number. An-
Edrabius grandis Ashe, Timm, & Gallardo, tenna (Fig. 5) longer than head and pro-
Designated J. S. Ashe, R. M. Timm, and thorax together; article 2 slightly shorter
M. L. Gallardo 1995." Deposited in the than, to subequal to, length of article 3,
Snow Entomological Museum, University article 4 quadrate to slightly elongate, ar-
of Kansas, La—wrence, Kansas. ticles 5-10 quadrate to slightly elongate.
Paratypes. 6, from the following local- Pronotum (Fig. 4) moderately transverse,
ities. Argentina: Rio Negro Prov., 3-V- about 1.4-1.5 times as wide as long; with-
1986, M. H. Gallardo #833, ex. Ctenomys out postero-lateral macroseta; microsetae
haigi (lEEUACH 1535) 9, 2 males 2 fe- on antero-lateral border variable from
males. Same locality, date, and collector, sparse and located in antero-lateral half, to
MHG
#837, ex. Ctenomys coyhaiquensis moderately dense and extended along lat-
(IEEUACH 1539), 1 male. Chile: Coyh- eral margin from near posterior third of
aique Prov.; 4.5 km SE Coyhaique Alto, pronotum to antero-lateral angles and
Fundo Los Flamencos, 750 m; M. H. Gal-
along lateral third of anterior margin; in-
lardo #1092, ex. Ctenomys coyhaiquensis 6 tegument with faint microsculpture, sculp-
(IEEUACH 4233), 1 male. Paratypes de- ticells isodiametric laterally but slightly
posited in IEE—UACH and KSEM. elongate medially, surface strongly shin-
Distribution. Known from the Rio Ne-
ing; micropunctures extremely fine and in-
gro Valley in Argentina and adjacentCoyh-
conspicuous. Elytra with moderate sized,
aique in—Chile. uniformly distributed, yellowish microse-
Hosts. Collected from Ctenomys coy- tae, punctures small. Abdomen uniformly
haiquensis in Coyhaique, Chile, and C. hai-
covered with silky vestiture of moderately
gi in Rio Negr—o Province, Argentina. dense yellowish microsetae.
Discussion. Specimens of this species —
Male. Posterior margin of tergum VIII
are among the largest ofany described spe-
broadly and moderately emarginate. Poste-
cies of Edrabius. They can be recognized
rior margin of sternum VIII broadly and
by: large size; relatively elongate antenna
deeply emarginate, emargination broadly
with elongate antennomeres; head and pro-
notum densely reticulate with isodiametric rounded internally, width of emargination
sculpticells; integument of head and pro- about 2.3 tim—es depth.
notum without micropunctures; microsetae Aedeagus.—As in Fig. 6.
on lateral margins of head and pronotum Holotype. Male, with labels as follows:
very small and sparsely distributed; and, the "Chile: Bio-Bio Prov.; LagunaLaja, 21-III-
distinctive aedeagus. 1987, M. H. Gallardo 1011 & 1012, ex.
Ctenomys maulinus maulinus (lEEUACH
1640 & 1641)." "HOLOTYPE, Edrabius
Edrabius australis, new species australis Ashe, Timm, & Gallardo, Desig-
Figs. 4-6
nated J. S. Ashe, R. M. Timm, and M. H.
—
Description. Length 7.0-9.0 mm. Uni- Gallardo 1995." Deposited in Zoological
formly light reddish-brown. Head shape Collections of the Universidad Austral de
(Fig. 4) with lateral margins uniformly ta- Chile, Valdivi—a, Chile.
pered from rounded posterior angles ante- Paratypes. 12, same data as holotype;
riorly; integument of head with faint, iso- 11, Chile: same locality, date, and collector,
MHG
diametric microsculpture, microsculpture #1017, ex. Ctenomys maulinus mau-
736 PROCEEDINGS OFTHE BIOLOGICAL SOCIETY OFWASHINGTON
Figs. 4-6. Edrabius australis n. sp. 4. Head and prothorax, dorsal (scale 1.0 mm); 5. Antenna (scale =
1.0 mm); 6. Apex ofaedeagus, lateral (scale = 0.1 mm).
—
linus (lEEUACH 1646). Paratypes depos- Host. Collected only from Ctenomys
ited in ffiEUA—CH and KSEM. maulinus maul—inus.
Distribution. Known only from Petron- Discussion. This species can be distin-
quines, Laguna Laja, Bio-Bio Province, guished by the relatively faint reticulation
Chile. of the head and prothorax with extremely
VOLUME 109, NUMBER4 737
Figs. 7-9. Edrabius chilensiformis n. sp. 7. Headandprothorax, dorsal (scale =1.0mm); 8. Antenna(scale
1.0 mm); 9. Apex ofaedeagus, lateral (scale = 0.1 mm).
fine and inconspicuous micropunctures, and and tapered from broadly-rounded posterior
the distinctive aedeagus. angles to anterior margins; integument with
moderate, elongate, irregularly wavy mi-
Edrabius chilensiformis, new species
crosculpture, sculpticells obsolete to absent
—Figs. 7-9 medially, integument strongly shining; mi-
Description. Length 5.0-6.0 mm. Red- cropunctures numerous, very minute; mi-
dish-brown. Head shape (Fig. 7) rounded crosetae on lateral margins behind eye
—
738 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
moderately dense. Antenna (Fig. 8) about within Edrabius characterized by the syna-
as long as head and pronotum together; ar- pomorphous condition of an upturned and
ticle 2 subequal in length to article 3, arti- apically pointed aedeagus (see Fig. 9, and
cles 4-10 quadrate to subquadrate. Prono- fig. 2C in Scheerpeltz 1957). In contrast,
tum (Fig. 7) moderately transverse, about these two species appear to retain several
1.4 times as wide as long; with postero-lat- plesiomorphic characteristics not found
eral macroseta; microsetae on antero-lateral among other known Edrabius. These ap-
margin prominent and more or less densely parent plesiomorphies include: presence of
distributed in anterior half of lateral mar- a postero-lateral seta on the pronotum (also
gins and along anterior third of anterior found among many free-living quediines, as
margins, integument with faint, irregular well as the amblyopinines Amblyopino-
wavy microsculpture, sculpticells obsolete des, Amblyopinus, Megamblyopinus, and
to absent medially, surface strongly shining; Myotyphlus, but notpresenton otherknown
micropunctures numerous, very minute. El- Edrabius), and the very weakly developed
ytra with moderately dense, yellowish mi- cluster of long aciculate setae on the apex
crosetae, punctures moderate in size. Ab- of the lateral plates of abdominal segment
domen uniformly covered with silky vesti- 9 (very strongly developed among other
—
ture of very densely distributed, yellowish known Edrabius see Seevers 1955, fig.
microseta—e. 44G). This suggests that these two species
Male. Posterior margin of tergum VIII occupy a relatively basal position in the
very shallowly and broadly emarginate.
phylogeny of Edrabius.
Posterior margin of sternum VIII broadly
It is also interesting that both of these
and deeply emarginate, emarginationbroad- species are known from caviomorph ro-
ly rounded; width of emargination about dents otherthan Ctenomys in the family Oc-
2.0 times depth.
— todontidae: Edrabius chilensis from the
Aedeagus.—As in Fig. 9. rock rat, Aconaemysfuscus and E. chilen-
Holotype. male, with labels as follows:
"Chile: Coquimbo Prov.; 10 km N Puente siformis from the degu, Octodon degus. In
contrast, most other Edrabius are known
Los Molles, 32°09'S, 71°3rw, 26-VII-
from Ctenomys (the only exception is E.
1976, R. E. Martin #1470, ex. Octodon de-
gus 9 (FMNH 119659)." "HOLOTYPE, kuscheli from the nest of a cui. Galea mus-
Edrabius chilensiformis Ashe, Timm, & teloides (Caviidae), but see below).
Gallardo, Designated J. S. Ashe, R. M.
Timm, and M. L. Gallardo 1995." Depos- New Records
ited in the Field Museum of Natural His-
tory, Chicago—, Illinois. Edrabius alticolus Seevers. Bolivia:
Paratypes. 3, same data as holotype. Dept. Oruro; 3.5 km E Huancaroma,
ParDaitsytpreisbudteipoons.i—tedKninoFwnMNoHnlyanfdrKomSECMo.- 69-,VINIKI-11918545,0e(x.MSCBte5n5o3m7y7s),o1pimmaules.oOpriumruos;
quimbo—Province, Chile. 2.5 km NE Huancaroma, 3720 m, 6-VINIIK-
Host. Collected from Octodon degus 1984, ex. Ctenomys opimus opimus 9,
(Octodontidae)—. 11566 (AMNHW260837), 2 males. Oruro; 1
Discussion. This species is closely re- km N, 5 km Pomata Ayte, Rio Barros,
lated to Edrabius chilensis Scheerpeltz 11-IX-1986, ex. Ctenomys opimus opimus
from which it can be distinguished by the S, NK 14549 (AMNH 263040), 1 male 1
denser abdominal setation and distinctive female. Oruro; Huancaroma, 2-X-1986, ex.
NK
aedeagus of E. chilensiformis. Edrabius Ctenomys opimus opimus 9, 14765
chilensis and E. chilensiformis appear to (MSB 57197), 2 males. Chile: Parinacota
form a distinctive monophyletic group Prov.; D. Reise #2710, ex. Ctenomys opi-
.
VOLUME 109, NUMBER 4 739
mus (lEEUACH 4332), 2 males 2 females nacota Prov.; ex. Ctenomys opimus, 3 males
(KSEM and lEEUACH). 4 females (lEEUACH and KSEM).
Edrabius argentinus Seevers. Argentina: Edrabius philippianus Fauvel. Fauvel
Mendoza Prov.; 5.7 km NW Villavicencio, (1900) described E. philippianus from
2800 m, 31 December 1981, Richard D. Ctenomys sp. from Antofagasta, Chile. We
Sage #10656, ex. Ctenomys haigi (MVZ herein correct the type host identification to
162936), 1 male (KSEM). Seevers (1955: be C. fulvus as that is the only species of
258) described E. argentinus from "ex nido tuco-tuco occurring in Antofagasta (Gallar-
de Ctenomys" from Argentina: Catamarca; do 1991).
Hualfin (near Tucuman). On the basis ofthe Edrabius weiseri Seevers. Bolivia: Dept.
locality, we believe the hostto be Ctenomys Oruro; 7 km S, 4 kmE Cruce Ventilla, 3450
tucumanu—s. m, 30-IX-1986, ex. Ctenomys opimus opi-
Notes. This specimen differs from the mus ?, NK 14748 (MSB 57194), 1 male.
type series of Edrabius argentinus in hav- Dept. Potosi; 2 km E ENDE Camp, Laguna
ing a slightly longer antenna with longer Colorado, 4280 m, 16-IX-1986, ex. Cteno-
articles 4-10, more uniformly rounded lat- mys opimus opimus 9, NK 14571 (AMNH
eral margins of the pronotum and mostly 263051), 1 male. Potosi; 2 km E ENDE
isodiametric microsculpture on pronotum Camp, Laguna Colorado, 4278 m, 16-IX-
(more wavy on specimens in type series). 1986, ex. Ctenomys opimus opimus 9, NK
However, the aedeagus is highly distinctive 14572 (MSB 57204), 7 males 20 females
and cannot be distinguished from the ae- (KSEM).
deagus of the holotype of E. argentinus.
Therefore, we have chosen to assign the
Discussion
specimen from Mendoza Province to E. ar-
gentinus in spite of the minor differences Two major groups of Edrabius are ap-
noted above. It is possible that a new sub- parent. One, represented by E. chilensis and
species should be established for the Men- E. chilensiformis, is found on Aconaemys
doza population; however, until more spec- and Octodon respectively, both in the fam-
imens ofE. argentinus are known from the ily Octodontidae (Table 1). These two small
original population, the Mendoza Province species of Edrabius share the synapomor-
population, and other intervening popula- phy of a sharply pointed and upturned apex
tions, it would be premature to describe to the aedeagus. However, they share a
such a subspecies. numberofplesiomorphic features notfound
Edrabius chilensis Scheerpeltz. Chile: in other Edrabius (see discussion under E.
Cautin Prov.; Quetropillan; P. Mondaca chilensiformis)
#439, ex. Aconaemys porteri (lEEUACH The second major Edrabius lineage is
4119), 1 male 1 female. Malleco Prov.; made up ofthose species that have the apo-
Parque Nacional Nahuelbuta, 10-1-1976, morphic conditions of the following char-
Robert E. Martin #1339, ex. Aconaemys acteristics: that is, pronotum without a pos-
fuscus, 1 —male (lEEUACH and KSEM). tero-lateral macroseta, and a very distinct
Notes. The specimen from Malleco and prominent "pencil" of aciculate setae
Province has an aedeagus that is slightly on the apices of the lateral styli of abdom-
more robust apically than that of the spec- inal tergum IX. This lineage includes all the
imens from Cautin and that shown in other known species ofEdrabius. Members
Scheerpeltz's (1957) figure. However, this of this second lineage are found primarily
slight difference does not seem sufficient to on various species of the genus Ctenomys,
assign this specimen to a new species. the sole genus in the family Ctenomyidae,
Edrabius peruanus Seevers. Chile: Pari- though all known specimens ofE. kuscheli
'
740 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASfflNGTON
—
Table 1. Summary ofknown general distribution and hosts ofEdrabius species (Staphylinidae, Amblyopi-
nini).
Generaldistribution
E. alticolus Seevers
Peru: Tacna Prov. Ctenomysfulvus Seevers, 1955
Bolivia: Oruro Prov. Ctenomys opimus this paper
Chile: Parinacota Ctenomys opimus this paper
E. argentinus Seevers
Argentina: Catamarca "nest of Ctenomys'" [Ctenomys tucumanus] Seevers, 1955
Argentina: Mendoza Prov. Ctenomys mendocinus this paper
E. australis Ashe, Timm, & Gallardo
Chile: Bio-Bio Prov. Ctenomys maulinus maulinus this paper
E. chilensiformis Ashe, Timm, & Gallardo
Chile: Coquimbo Prov. Octodon degus this paper
E. chilensis Scheerpeltz
Chile: Curico "An Ratten" Scheerpeltz, 1957
Chile: Malleco Prov. Aconaemysfuscus this paper
Chile: Cautin Prov. Aconaemysporteri this paper
E. grandis Ashe, Timm, & Gallardo
Argentina: Rio Negro Prov. Ctenomys haigi this paper
Chile: Coyhaique Prov. Ctenomys coyhaiquensis this paper
E. kuscheli Scheerpeltz
Chile: Arica-Lipiche ''nest ofGalea musteloides' Scheerpeltz, 1957
E. pearsoni Seevers
Peru: Puno Prov. Ctenomys opimus nigriceps Seevers, 1955
E. peruanus Seevers
Peru: Puno Prov. Ctenomysperuanus Seevers, 1955
Chile: ParinacotaProv. Ctenomys opimus this paper
E. philippianus Fauvel
Chile: Antofagasta Ctenomysfulvus Seevers, 1955
E. weiseri Seevers
Argentina: Jujuy host unknown Seevers, 1955
Bolivia: Dept. Oruro Ctenomys opimus opimus this paper
Bolivia: Dept. Potosi Ctenomys opimus opimus this paper
were found in the nest ofa cui. Galea mus- whereas all three specimens ofthe type se-
teloides (but see below) (Table 1). ries of E. chilensis have such setae.
Scheerpeltz (1957), illustrated specimens Furthermore, Seevers (1955), in a quote
of Edrabius kuscheli, E. philippianus, and from O. P. Pearson (page 254), notes that
E. chilensis showing aposterolateral setaon Galea musteloides frequently use old Cten-
the pronotum. However, our examination of omys burrows. If true, then movement of
the holotype of E. chilensis, all paratypes individuals of Galea into Ctenomys bur-
of E. kuscheli, and specimens labeled E. rows that already had a population of Ed-
philippianus (almost certainly misidenti- rabius could account for this unusual host
fied, see above) from Scheerpeltz's collec- record.
tion clearly show that specimens of both Members of the genus Ctenomys, the
species lack posterolateral pronotal setae. tuco-tucos, are small to mid-sized (100-