Table Of ContentPROC. ENTOMOL. SOC. WASH.
109(3), 2007, pp. 696-699
MORIBAETIS MIMBRESAURUS, NEW SPECIES (EPHEMEROPTERA:
BAETIDAE): FIRSTREPRESENTATIVEOFTHEGENUSNORTHOFMEXICO
W. P. McCafferty
Department ofEntomology, Purdue University, West Lafayette, IN 47907, U.S.A.
(e-mail: [email protected])
—
Abstract. Unusually large baetid mayfly adults from Coconino County, Arizona,
USA are described as Moribaetis mimbresaurus, new species. The new species
represents the first known occurrence ofthe genus Moribaetis Waltz and McCafferty
north of the Neotropical Region. It is distinguished from Central American
congeners by having double cubito-anal intercalary veins and limited pigmentation
in the forewings, and a non-forked second longitudinal vein in the hindwing.
Key Words: mayflies, new species, new USA generic record, Baetidae
While working on the identification of eye, and small terminal segment of the
an extensive collection of alate mayflies genital forceps indicated that the may-
made by M. S. Sanderson in parts of flies in question represented a new spe-
Arizona during the 1980s and kindly cies with an obvious affinity with Central
donated by him to the Purdue Entomo- American species ofthe genus Moribaetis
logical Research Collection, I came upon Waltz and McCafferty.
highly unusual Baetidae adults that were Moribaetis has been known as a West-
not readily identifiable to any known ern Hemisphere group ranging from
genus from the USA. Their relatively tropical South America to southern
large size was not known for any Mexico, with three well-described nom-
Nearctic small minnow mayflies (Baeti- inal species common to Central America
dae) other than some Callibaetis Eaton, (Waltz and McCafferty 1985, Lugo-Ortiz
and they clearly did not belong to that and McCafferty 1996). Nominal South
group (e.g., they lacked both crossvena- American species are poorly known and
tion in the hindwings and body speck- dubius (see below). Moribaetis represents
ling). The largest non-Ca/Iibaetis baetids a relatively plesiotypic genus among the
in the USA have included Baetis magnus Baetodes complex of genera (Lugo-Ortiz
McCafferty and Waltz (throughout and McCafferty 1996, McCafferty and
much of the western USA) and the Baumgardner 2003), a distinctive clade
little-known B. palisadi Mayo (only from of Baetidae restricted to the Western
California), but the Arizona mayflies in Hemisphere and of Neotropical origin
question were considerably larger than (McCafferty 1998).
those species. The combination of large The purpose of this paper is to de-
size, membrane pigmentation in the scribe the newly discovered species of
forewing, the basally margined, distally Moribaetis. This discovery is significant
oriented, sharp costal process of the because the new species represents a dis-
hindwing, short stalk of the turbinate junct country record for the genus, is
—
VOLUME NUMBER
109, 3 697
USA
exceptionally large for baetines, with terga 7-10 somewhat darker, and
and is possibly rare because presumably with some dark brown infuscation dis-
it would be difficult to overlook such tally on tergum 10. Sterna pale cream;
a mayfly if it were common in Arizona, sterna 2 7 submedially with pair of
a state whose mayfly fauna has been short, oblique, light brown dashes fol-
relatively well studied (see Lugo-Ortiz lowed posteriorly by pair of small, light
and McCafferty 1995). brown dots. Genitalia as in Fig. 5:
forceps bases very well demarcated and
Moribaetis tnintbresaurus McCafferty, with some distomedial development;
new species apical forceps segment short and set off
(Figs. 1-5) by lateral indentation only; subgenital
— plate prominent and with straight distal
Male adult. Body length 9.3-
border for entire distance between for-
9.5 mm. Forewing length 9.6 10.0 mm.
ceps. Cercus uniformly light brown.
Hindwing length 1.2 mm. Cercus length Female adult.—Body length 10.1 mm.
19.0 mm. General coloration light to Forewing length 10.1 mm. Hindwing
medium brown. Head with turbinate length 1.2 mm. Cercus length unknown.
eyes ovoid, yellow, and approximate
Coloration as per male, except markings
(Fig. 1); stalk of turbinate eye relatively not as apparent in some. Wing venation
short and yellow (Fig. 2). Scape and as described for male, although in some,
pedicel somewhat darkened basally. basal margin of hindwing costal process
Thorax with all nota medium brown not as distinct as in male and marginal
(pronotum somewhat darker). Mesono- intercalary veins of hindwing not as
tum with some highlights posteriorly.
distinctive. —
Mesopleurum pale with profuse medium Material examined. Holotype: S
and dark brown markings. Forefemur adult, Arizona, Coconino Co, Oak Cr
light brown with medium brown cloud at pumphouse wash (floating on water),
apically on both surfaces. Foretibia and 3-III-1984, M. W. Sanderson (deposited
foretarsus somewhat darker than fore- in the Purdue Entomological Research
femur and with distinct markings. Mid- Collection, West Lafayette, Indiana).
and hindlegs pale throughout except Other material: 1 S adult (some parts
femora with brown cloud apically as dissected, in microvial and on slide), and
per foreleg. Forewing (Fig. 3) with tan 2 ? adults (some parts dissected on
infuscation limited to distal halfofcostal slide), same locale and depostion data
and subcostal areas; costal crossveins as holotype.
—
profuse and somewhat anastomose; mar- Etymology. The specific epithet is
ginal intercalary veins double through- a compound noun in apposition and an
out (very difficult to see in anal region). allusion to the lizard shape typified in
Hindwing (Fig. 4) with distally pointed, drawings ofthe ancient Mimbres culture
sharp costal process with basal margin- of the Southwest.
ation, and with three longitudinal veins; Discussion. Moribaetis mimbresaurus
second longitudinal vein not forked; one represents the sixth currently recognized
marginal intercalary vein between first species ofthe genus Moribaetis, although
and second longitudinal veins; two mar- the two recognized South American
ginal intercalary veins following second species, M. aneto (Traver) and M. comes
longitudinal vein and ending in distal (Navas), remain poorly known and pro-
margin; third longitudinal vein shorter visional at this time (Lugo-Ortiz and
and ending in anal margin. Abdomen McCafferty 1999, McCafferty 2000).
with terga light brown and unmarked, The only other South American name
PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
698
Figs. 1-5. Moribaetis mimbresaurus, male adult. 1, Head (dorsal). 2, Head (lateral). 3, Forewing. 4,
Hindwing. 5, Genitalia (ventral).
VOLUME NUMBER
109, 3 699
referred to Moribaetis, M. socius (Need- species of Moribaetis, whereas the anas-
hamand Murphy), is anomen diibiiim and tomose distal costal crossvenation could
not counted among the six recognized be viewed as autapomorphic within the
species. group. This could suggest that M.
The new species differs from the other mimbresaurus is a basal lineage among
species of Moribaetis in having the the Central-North American species, and
pigmented infuscation of the membrane furthermore based on its geographic
of the forewing hmited to the distal distribution that it is relictual in Arizona,
costal and subcostal area, and cross- possibly having been much more wide-
ventation in the distal costal area some- spread in Mexico and Central America
what anastomose. Central American at one time. Future discovery of the
species are known to have various larval stage of the species should shed
degrees of patterned pigmentation in considerable light on these possibilities.
the forewing. The two recognized South
Literature Cited
American species are devoid of wing
pigmentation except perhaps at the wing Eaton, A. E. 1883-88. A revisional monograph of
base, and they differ also from the recent Ephemeridae or mayflies. Transactions
of the Linnaean Society of London, Second
North-Central American forms in that Series in Zoology 3: 1-352.
they have a less distinct costal process of Flowers, R. W. 1979. A newspecies ofBaetis from
the hindwing that is not set offor distally Panama (Ephemeroptera: Baetidae). Pan-Pa-
oriented, and are considerably smaller in cific Entomologist 55: 187-191.
body size. The new species also differs Lugo-Ortiz, C. R. and W. P. McCafferty. 1995.
Annotated inventory of the mayflies (Ephe-
from the other Moribaetis adults, except meroptera) of Arizona. Entomological News
for the South American M. aneto (Tra- 106: 131-140.
ver), in not having the second longitudi- . 1996. Phylogeny and classification of the
nal vein of the hindwing forked, al- Baetodes complex (Ephemeroptera: Baetidae),
with description ofa newgenus. Journalofthe
though otherwise the hindwing venation
North American Benthological Society 15:
is quite similar. In addition, although it 367-380.
is common for the Central American . 1999. Revision ofSouth American species
species to have triple marginal intercal- ofBaetidae(Ephemeroptera) previouslyplaced
aries in the cubito-anal cells of the in Baetis and Pseudocloeon Klapalek. Annales
forewing, these veins are double in M. de Limnologie 35: 257-262.
McCafferty, W. P. 1998. Ephemeroptera and the
mimbresaurus. This character is not re- great American interchange. Journal of the
solved for the two South American North American Benthological Society 17:
species. For comparisons, the other 1-20.
pertinent adult descriptions of Central . 2000. Notations on South American
Baetidae (Ephemeroptera). Entomological
American Moribaetis species, including News 111: 375-397.
figures of the wings, are as follows: M. McCafferty, W. P. and D. E. Baumgardner. 2003.
salvini (Eaton): Eaton (1885, plate 16, Lugiops maya, a new genus and species of
fig. 29a); M. maculipennis (MFlowers): Ephemeroptera(Baetidae) fromCentralAmer-
Flowers (1979, figs. 15); and maca- ica. Proceedings of the Entomological Society
ofWashington 105: 397-406.
ferti Waltz: McCafferty and Lugo-Ortiz McCafferty, V^. P. and C. R. Lugo-Ortiz. 1998.
(1998, figs. 1-8). The adult of Moribaetis macaferti (Ephemer-
The venational traits of M. mimbre- optera: Baetidae). Entomological News 109:
saurus (double marginal intercalaries in 117-121.
the cubito-anal cells of the forewing and WaltzM,oribRa.etiDs.: aanndewWg.enuPs. ofMcNCeaoftfreorptiyc.al1B9a8e5-.
non-forked main veins in the hindwing) tidae (Ephemeroptera). Proceedings of the
are apparently plesiomorphic with re- Entomological Society of Washington 87:
spect to the Central-North American 239-251.
