Rudolfina cavernicola, a new species of cave-associated Sphaeroceridae (Diptera) from Colorado and Arizona

4 Pages·1997·1.8 MB·

by  S A Marshall

PROC. ENTOMOL. SOC. WASH.
99(4), 1997, pp. 641-644
RUDOLFINA CAVERNICOLA, A NEW SPECIES OF CAVE-ASSOCIATED
SPHAEROCERIDAE (DIPTERA) FROM COLORADO AND ARIZONA
S. A. Marshall and S. Fitzgerald
(S.A.M) Department ofEnvironmental Biology, University ofGuelph, Guelph, Ontario,
Canada NIG 2W1; (S.F) Department of Entomology, Colorado State University, Fort
CO
Collins, 80523, U.S.A.
—
Abstract. Rudolfina cavernicola, new species, is described from several collections
from Kremmer's Cave, Colorado, and a single specimen from Arizona. Characters are
given to separate the two western North American Rudolfina. Six species of Sphaerocer-
idae are listed from Kremmer's Cave, and the cave habitat is described.
Key Words: Sphaeroceridae, Rudolfina, caves
The genus Rudolfina Rohacek can be rec- ries of the new species described here, Ru-
ognized on the basis of the stout, upturned dolfina cavernicola, is from Kremmer's
female cerci that are fused with the epiproct Cave, Colorado. Spelobia pseudosetaria
and middle part of tergite 8; the long co- (Duda), Spelobia tuberculosa Marshall,
stagial bristle; and the characteristic dark Spelobia maculipennis (Spuler), Xe-
lobes of male sternite 5. There is one de- nolimosina sicula Marshall and Limomyza
scribed Nearctic species, Rudolfina digitata cavernicola Marshall were collected in
Marshall, and one described Palearctic spe- Kremmer's Cave with Rudolfina caverni-
cies, R. rozkosnyi (Rohacek), both ofwhich cola.
exhibit disjunct arctic-alpine distributions Key to Western North American
(Marshall 1991). Rudolfina includes several Rudolfina
undescribed southeastern Nearctic and Neo-
- Eye height ca. 1.8x genal height. Secondcos-
tropical species, but Rudolfina cavernicola, tal sector longer than third. Male sternite 5
new species, is closely related to the west- with 3 posteromedial lobes, outer 2 small,
em North American R. digitata and the Eu- equal to one another (Fig. 4). Distal lobe of
ropean R. rozkosnyi. surstylus setose, rounded (Fig. 1). Gonostylus
expanded preapically (Fig. 3)
The cave-inhabiting Sphaeroceridae of Rudolfina cavernicola, new species
eastern North America were discussed by - Eye height ca. 1.4x genal height. Second cos-
Marshall and Peck (1984), who recorded 10 tal sector shorter than third. Male sternite 5
species of which at least one (Spelobia te- with two posteromedial lobes, one bifid and
one single. Distal lobe of surstylus elongate,
nebrarum (Aldrich)), is a true troglobite, bare, with multiple translucent lobes. Gono-
and at least one, (Terrilimosina racovitzai stylus narrow, tapered apically
(Bezzi)), is a troglophile. Little is known Rudolfina digitata Marshall
about cave Sphaeroceridae in western North
America, although one troglophilic species, Rudolfina cavernicola Marshall and
Limomyza cavernicola Marshall, was re- Fitzgerald, New Species
cently described from in or near caves in (Figs. 1-6)
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Missouri, Kentucky, Oklahoma, and Colo- Description. Body uniformly pale
rado (Marshall 1997). Most of the type se- brown; length ca. 2.0mm. Interfrontal plate
642 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Figs. 1-6. Rudolfina cavernicola. 1-4, Male abdominal structures. 1, Terminalia, left lateral. 2, Terminalia,
posterior. 3, Aedeagus and associated structures. 4, Sternites 5-7. 5-6, Female abdominal structures. 5, Tergites
7-9 and cerci. 6, Spermathecae.
equal in depth and width, bordered by 3 anteroventrally with a row of short, stout
interfrontal bristles, the lower pair cruciate bristles on distal two thirds; mid tibia of
over lunule. Eye height 1.8 times genal female with a single small anteroventral
height. Mid tibia of male slightly curved. bristle near middle. Dorsocentral bristles in
VOLUME 99, NUMBER 4 643
a single large prescutellar pair; 2 pairs of very similar in structure. Both species have
prescutellar acrostichal bristles, middle pair a divided tergite 8, with the anterior part of
very long. Wing with costagial bristle long, tergite 9 separate from the main part ofter-
longer than dorsocentral bristle; second cos- gite 9 and between the halves of tergite 8.
tal sector slightly longer than third, costa However, tergite 8 of R. cavernicola is not
ending 2—3 vein widths beyond apex of strongly wrinkled like that of R. digitata,
R4+5 and the spermathecae are longer. The biol-
Male abdomen: Sternite 5 with 3 ogy of R. digitata is unknown, but since it
posteromedial lobes (Fig. 4). Surstylus with has smaller eyes than those of R. caverni-
a broad, subquadrate basal part and a nar- cola it is assumed that both ofthese species
row, setose distal part (Fig. 1). Epandrium are subterranean in habit.
with 3 long posterodorsal bristles on each Kremmer's Cave is a small solution cave
side (Fig. 2). Subanal plate large, broadly formed in Ingleside limestone along the
fused; cerci small, setose. Gonostylus api- east slope of the hogback in northern Col-
cally expanded, boot-shaped (Fig. 3). Dis- orado (Parris 1973). The cave is basically
tiphallus broad, complex, functional ventral one 100 ft. long room sloping downward at
surface with diverging arms, distal part of about 35°. The room is largest medially,
functional dorsal surface with crenulate about 20 ft. wide with a 7 ft. ceiling, and
plate on each side. narrowest near the entrance and low, ter-
Female abdomen: Tergite 9 (Fig. 5) pro- minal crawlway. The pit entrance is about
longed into a short, blunt lobe between the 2 ft. in diameter and 3 ft. deep, and al-
2 halves of tergite 8, lobe dark and sepa- though the cave is short, it becomes cave-
rated from rest of tergite 9 by pale area, like (dark, humid, and of a relatively con-
main part of tergite 9 with a longitudinal stant temperature) quickly, due to the small
pale strip. Sternite 7 large, dark, posterior opening to the outside. In August the am-
margin spinulose; sternite 8 reduced, with bient air temperature taken at 25 ft. in from
4 small, stout bristles. Sternite 9 postero- the bottom of the pit entrance was 42° F
medially thin and pale. Cercus distinctly Specimens of R. cavernicola were col-
upturned, with a stout spur at apex (Fig. 5). lected within the first 25 ft. from the bottom
Spermathecae round, tire-shaped; stem ofthe pit entrance, henceforth referred to as
long. the entrance-way, using an aspirator, and at
Holotype.—(?, COLORADO. Larimer 30 and 85 ft. from the bottom of the pit
Co., 3 April, 1992, S. Fitzgerald, Krem- entrance with pitfall traps baited with slices
mer's Cave, 6000', Rt 287,6 mi N of Jet. of ripe banana. Since R. cavernicola was
Rt. 14. (Cana—dian National Collection) collected in sympatry with several other
Paratypes. Colorado. Kremmer's Cave, species of sphaerocerids, field identification
5,8,22.viii.l996 (1(?,2$, 30.ix-27.x.l996; was not possible and thus, the following
9c?,3? in pit trap @85' from entrance; 1 9 general observations include all above men-
@
in pit trap 30' from entrance; none taken tioned species. In the entrance-way flies
in pit traps @ 9' from entrance during same were observed resting or running on pieces
period), Scott Fitzgerald (University of of moist wood, among broken rock, rock
Guelph and Colorado State University col- pillars (probably reminiscent of the cave's
lections). Arizona. Hospital Flat, Pinaleno discovery during a limestone mining oper-
Mts., 8950', 3.viii.l965, H. Leech (M, Cal- ation (Parris 1973)), and on cave walls.
ifornia Academy of Sciences). Flies jumped or ran when disturbed, but
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Comments. Although the male genita- were never observed to fly.
lia of R. cavernicola are strikingly different Rodent droppings, most covered with
from those of R. digitata, the female ter- various microfungi, seem to be the most
minalia of these closely related species are abundant food source in Kremmer's cave.
644 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
However, the nature of the pit entrance al- Literature Cited
lows rain water to wash in organic debris,
a minimal amount of bat guano exists near Marshall, S. A. 1997. Limomyza, a new genus of
the back ofthe cave, and a rodentjaw bone primitive Limosininae (Diptera: Sphaeroceridae),
with five new speciesfromUnitedStates,Mexico,
suggests at least an occasional carcass, all and Central America. Proceedings of the Ento-
of which may be possible larval food mological Society ofWashington 99:279-289.
sources. As most cave-associated sphaero- Marshall, S. A. 1991. Riidolfina digitata sp.nov., a
cerids utilize a wide range ofbreeding sub- new nearctic sphaerocerid with a disjunct alpine-
strates (Papp and Plachter 1976), and R. arctic distribution. Canadian Entomologist 123:
621-626.
cavernicola was apparently attracted to ba-
Marshall, S.A. and S.B. Peck. 1984. Distribution of
nana, it is probable that R. cavernicola is cave-dwelling Sphaeroceridae (Diptera) of North
not restricted to a single food source. America. Proceedings of the Entomological So-
ciety ofOntario: 115: 37-41.
Acknowledgments
Parris, Lloyd E. 1973. Caves of Colorado. Boulder,
Thanks to Rebecca Langstaff for prepar- Colorado, Pruett Publishing Co., 247 pp.
Papp, L. and Plachter, H. 1976. On cave dwelling
ing the illustrations, and to Alison Foley for
Sphaeroceridae from Hungary and Germany. An-
help with cave measurements and the col- nales Historico Naturales Musei Nationalis Hun-
lection of traps. garica 68: 195-207.