Two new species of Asyndetus Loew, and notes on the identity of A. interruptus Loew (Diptera: Dolichopodidae)

6 Pages·1997·2.7 MB·

by  H Robinson

PROC. ENTOMOL. SOC. WASH.
99(3), 1997, pp. 477-482
TWO NEW SPECIES OF ASYNDETUS LOEW, AND NOTES ON THE
IDENTITY OF A. INTERRUPTUS LOEW (DIPTERA: DOLICHOPODIDAE)
Harold Robinson and Mark Deyrup
(HR) Department of Botany, National Museum of Natural History, Smithsonian Insti-
tution, MRC 166, Washington, DC 20560, U.S.A.; (MD) Archbold Biological Station,
RO. Box 2057, Lake Placid, I^ 33862, U.S.A.
—
Abstract. Asyndetus archboldi is described as new from the sand hills of peninsular
Florida; A. wirthi is described from Jamaican and Antiguan material previously deter-
mined as A. interruptus. Observations are given on the type specimen of A. interruptus
Loew in Havana, Cuba.
Key Words: Asyndetus, new species, Dolichopodidae, Florida, West Indies
Two new species of Asyndetus Loew Asyndetus archboldi Robinson and
are described, the first based on collec- Deyrup, new species
tions from the xeric uplands of Florida, (Figs. 1-3)
and the second based on West Indian ma- —
Holotype male. Length 1.9 mm; wing
terial previously identified as A. interrup- 1.6 mm by 0.6 mm. Face 1.4 times longer
tus Loew.
than wide, sides parallel; face and front
The Florida Asyndetus is described and
with dense silvery pollen. Palpus black,
discussed as part of an effort to catalog the
with several stout black setae; proboscis
species of arthropods found in the Florida
black; upper postocular setae black, lower
Scrub habitat. Florida scrub is a fire-main- postocular setae white. Antenna black,
tained habitat that occurs on xeric sand
scape widened apically, without hairs or se-
ridges in scattered localities in Florida. The
tae; pedicel about twice as long dorsally as
scrub habitat supports a number of species
ventrally in external lateral view, with a
of plants and animals found nowhere else, dorsal apical enlarged black seta; 1st fla-
and the rapid disappearance and degrada-
gellomere with a long, dorsal, sub-basal
tion of the remaining areas lends an urgen- arista, encircled by a deep groove just dis-
cy to the project ofcataloguing the resident tad of arista, so flagellomere appears divid-
arthropods. For more detailed descriptions ed into 2 parts.
of Florida scrub, see Myers (1990) and Thorax dark gray with light gray pollen,
Abrahamson et al. (1984); for more infor- with extremely faint greenish and coppery
mation on Florida scrub arthropods, see reflections when viewed in fluorescent
Deyrup (1990) and Deyrup and Eisner light, with both green and coppery reflec-
(1993). tions conspicuous in incandescent light; all
All specimens are presently deposited setae black; only 4 acrostichals in single ir-
at either the National Museum of Natural regular row, 4 pairs of dorsocentrals; 2
History, Smithsonian Institution, (USNM) large scutellarbristles; 1 blackproepistemal
or the Archbold Biological Station (ABS). seta above fore coxa.
478 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Coxa black, front and middle coxa with lector as holotype, 30 Apr. 1989, road 6,
an anterolateral irregular row of bristles, scrubby flatwoods; 2 ? same locality, col-
:
hind coxa with an external basal bristle; lector as holotype, 23 June 1989, white
femora black with conspicuous green re- sand trail, scrub; 1 $: same locality, collec-
flections and yellowish apices; front and tor as holotype, 29 June 1989, white sand
middle tibiae yellowish, hind tibia and all fire lane; 1 6,1 9; 4 cJ, 15 9, same lo-
tarsi black; hairs and setae on legs black; cality, collector as holotype, 16 June 1992,
middle and front tibiae with small seriate inopina scrub, line road; 1 c?, 8 9: same
setae and single enlarged apical seta, hind locality, collector as holotype, 18 June
tibia with paired anterodorsals and poster- 1992; 3 (?, 3 9: same locality, collector as
odorsals at basal fifth, at two-thirds and holotype, 19 June 1992; 1 6: same locality,
subapically; an unpaired anterodorsal at ba- collector, habitat as holotype, 18 Apr. 1996;
sal third. Front basitarsus with a subapical 3 6,1 9: same locality, collector, habitat
external cluster of small thick setae; 2nd, as holotype, 23 Apr. 1996; 2 6, \ 9: same
3rd and 4th segments compressed, 5th seg- locality, collector, habitat as holotype, 24
ment depressed; pulvilli about as long as Apr. 1996; 1 6: Lake Placid, Placid Lakes
rest of 5th segment, claws about half as Development, 15 June 1992, M. Deyrup;
long as pulvilli, shorter than 3 apical bris- same locality as holotype, 26 June 1989, R.
tles of 5th segment; lengths of tarsal seg- Shumate, Malaise trap, Ceratiola area.
ments from base: tarsus I, 0.30, 0.09, 0.06, (ABS): 9 6,1 9: same locality, collector,
0.04, 0.05 mm, pulvilU 0.05 mm; tarsus II, habitat as holo—type, 1 May 1996.
0.35, 0.16, 0.11, 0.08, 0.08 mm, pulvilh Etymology. Named for the Archbold
0.03 mm; tarsus III, 0.25, 0.18, 0.12, 0.08, Biological Station, where most of the type
0.08 mm, pulvilli 0.02 mm. material was—collected.
Wings appearing rather smoky due to Diagnosis. Because ofthe pale fore tib-
dense, uniform microtrichae; veins dark ia, black hind tibia, and the male face that
brown; costa ending at apex of 3rd vein; is higher than wide, Asyndetus archboldi
4th vein discontinuous, the "broken" ends keys in Robinson (1964) to couplet 6, but
apparently overlapping, at least as folds; ca- differs from all the species in that part of
lypter, its setae, and knob of halter, ivory. the key by the small first flagellomere of
Abdomen dark gray with thin gray pol- the antenna. Relationship might be closest
len, with greenish and coppery reflections to some western species, particularly A. la-
that are almost imperceptible in fluorescent tus Van Duzee, from Bill Williams Fork,
light, conspicuous in incandescent light. Arizona, having a similar densely silvery
Tergal setae black, suberect, apical band on pollinose face and black palpi. The latter
mm
each tergite larger; genital capsule with 4 species is distinctly larger, ca. 3.5 long,
large equal setae. — is evidently from near water, and resembles
Allotype female. Length 2.2 mm; wing other possibly related western species in
2.0 mm by 0.7 mm. Coloration, pollinosity, having all the tibiae partly or wholly yellow
wing venation, tibial setae similar to male. (Van Duzee 1—916, 1919).
Front tarsi not modified, setae of tergites Discussion. Florida scrub habitat is the
shorter and more decumbent. antithesis ofhabitats preferred by most Dol-
Holotype.—Male: FLORIDA: Highlands ichopodidae: it is comparatively sterile, xer-
Co., Archbold Biological Station, 26 April ic, without nearby permanent water, with
1996, M. Deyrup. On open sand at edge of clumps of sclerophyllous, drought-adapted \
fire lane, Florida scrub habitat (USNM). plants, and patches of bare, white sand.
—
Paratypes. (USNM): 6 6,39 (includ- Other species of Asyndetus are usually
ing allotype): same locality, date, collector, found on the seacoast or around permanent
habitat as holotype; 1 9: same locality, col- fresh water (Cole 1969). However, A. arch-
VOLUME 99, NUMBER 3 479
boldi shares a habitat trait with some of its one time. We expect that, when dipterists
congeners: it is associated with sandy plac- begin to scan the surface of open sand for
es. This is somewhat parallel to the situa- these tiny flies, that this species or similar
tion in pygmy mole crickets (Tridactylidae) species will be found in scrub elsewhere in
which live on algae growing in wet, sandy Florida, and perhaps outside of the state as
areas, except for a newly described species well.
from Florida scrub (Deyrup and Eisner
1996). This latter pygmy mole cricket feeds Asyndetus wirthi Robinson,
new species
on a recently discovered layer of algae that
grows about 3 mm below the surface ofthe (Fi—gs. 4-6)
bare sand, where light is easily transmitted Holotype male. Length 4.0 mm; wing
through the translucent grains and where at- 3.5 mm by 1.2 mm. Face ca. % to % as wide
mospheric drying is much reduced. The lar- as high, not recessed, white pollinose; front
vae are known for only one species of not noticeably wider than face at antennae,
Asyndetus (Williams 1938), that naturally metallic greenish color almost totally ob-
occurs at the entrances of crab holes on scured by grayish-white pollen. Palpus and
sandy beaches, and whose larvae have been proboscis black, the former with numerous
raised in vials where they were fed on dro- black setae. Antenna black; pedicel only
sophilid maggots. Almost all dolichopodid slightly produced above and on inner side,
larvae are similarly predacious, but the an- not longer above than below; first flagello-
imals on which they feed occur in a wide mere scarcely as long as high, with very
variety of habitats. At least some dolicho- short, blunt point below arista, arista borne
podid larvae are associated with algal mats at distal Va of upper edge, very near tip.
(Oldroyd 1964). Thus, we speculate that the Lower postocular setae white.
larvae of A. archboldi may be feeding in Thorax mostly metallic green obscured
the algal layer under the sand on which the with yellowish-gray pollen, with rather dis-
adults are found. The limited literature on tinct brown pollinose stripe dorsally be-
dolichopid larvae and pupae (Willams tween rows of dorsocentrals; acrostichals
1938; Smith 1952; Dyte 1959; Robinson distinctly biseriate; scutellum with small
and Vockeroth 1981) would be augmented hair on lateral margin; with series of 5 or 6
by discovery and description of the imma- small proepistemal setae above fore coxa of
ture stages ofA. archboldi. which those nearest the coxa are longer
Adults of Asyndetus archboldi occur on Legs dark, with some yellow at knees;
open sand at edges of fire lanes and in bare coxae and femora metallic green with gray-
patches between clumps of scrub plants. ish pollen. Setae on anterior surfaces of
These flies move quickly from place to coxae coarse, black. All femora with some-
place on the sand, seldom flying more than what irregular series of anteroventral and
a few mm above the surface. They may posteroventral setae, halfto three-fourths as
perch for a few minutes on debris, especial- long as widths of femora, a stouter antero-
ly the small dead leaves of scrub oaks. ventral seta at tip ofhind femur, 2 or 3 lon-
When individuals meet, they usually per- ger setae anterodorsally near tip ofhind fe-
form a rapid gyrating flight around each mur Fore tibia with 2 or 3 anterodorsals,
A
other, then separate. fly can be captured third and largest anterodorsal near middle,
by quickly placing a plastic bag over it, 1 distinct posterodorsal near middle, 2
then chasing it up into the bag, where it can small apicals above and below; middle tibia
be sucked up with an aspirator. We have with 2 large anterior bristles near '/<; and %,
collected one specimen in a Malaise trap, small anterodorsal near %, 3 rather small
but there seems to be no method for easily posterodorsals near '/j, -/^, and y^, 1 distinct
capturing large numbers of specimens at ventral near % and sometimes 1 smaller
—
480 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
near %, usually 5 large apicals; hind tibia Systematic Entomology Laboratory, Dip-
with 7 anterodorsdals of irregular lengths tera section of the U.S. Department of Ag-
staggered in 2 rows, basal in series very riculture.
small, the second, fourth and sixth in a Diagnosis. Asyndetus wirthi differs
more anterior row and slightly larger, with from A. interruptus by the face ofthe male
6 posterodorsals, the third and fifth large, being higher than wide, very gradually nar-
near % and %, with 5 large apicals. Tarsus rowed from the front rather than having a
with last segment slightly broadened, all slight but abrupt narrowing at the level of
pulvilli enlarged and longer than 5th seg- the antennae (Figs. 6, 7). The pedicel ofthe
ment, fore tarsus slightly felted ventrally, antenna has the upper edge scarcely longer
middle basitarsus with only a few ventral than the lower edge, the first flagellomere
spicules; lengths of tarsal segments from is scarcely as long as high with a very short
the base as: tarsus I, 0.52, 0.22, 0.17, 0.13, blunt point ventral to the arista, and the me-
0.17 mm, pulvilli 0.26 mm; tarsus II, 0.65, soscutum has brownish pollen between the
0.35, 0.22, 0.17, 0.13 mm, pulvilli 0.24 rows of dorsocentrals. Asyndetus interrup-
mm; tarsus III, 0.48, 0.43, 0.30, 0.17, 0.13 tus has the pedicel ofthe antenna distinctly
mm, pulvilli 0.20 mm. longer above than below, the first flagello-
Wings grayish with yellowish-brown mere is swollen at the base with the lower
veins; anal margin fully rounded. Vein 1 edge oblique to a short and sometimes
reaching costa near middle of wing; vein 3 sharp point, and the mesoscutum is evenly
distinctly curved backward near tip; last grayish or whit—ish pollinose above.
part of vein 4 broken at bend, broken ends Discussion. The distinction between
apparently slightly overlapping. Crossvein Asyndetus wirthi and Asyndetus interruptus
Va as long as terminal section ofvein 5. Ca- Loew was first made by Robinson (1975).
lypter, its setae and knob of halter whitish. Unfortunately, at that time, A. wirthi was
Abdomen metallic green dulled with gray thought to be A. interruptus, and specimens
pollen; hairs mostly short, hairs on sides of A. interruptus were described as a new
and stemites longer, marginal setae 2 or 3 species, A. bredini. The confusion was the
times as long as dorsal hairs. Genital cap- direct result ofinadequate knowledge ofthe
sule dark brown, bearing 4 stout bristles type specimen ofA. interruptus, supposedly
posteriorly. — deposited in the Poey collection in Havana,
Allotype female. Length 4.0-4.5 mm; Cuba. The type was said to be in a sealed
wing 3.5-3.9 mm by 1.3 mm. Face slightly tray.
higher than in male, with narrow clypeus In 1990, this situation was resolved
visible; antenna as in male. Fore and middle through a correspondent in Cuba, Gabriel
coxae with setae less coarse anteriorly; fem- Garcea G., who sent photographs of the
ora without long setae or bristles below; type specimen. Garcea reported that the
hind tibia with small anteroventrals; last type was in the Gundlach collection of the
segments of tarsi not broader, pulvilli not Ecology-Systematics Institute, Academy of
enlarged. — Sciences, in Havana, not in the Poey col-
Holotype. Male, JAMAICA: Falmouth, lection. The specimen is a male, with the
bay shore, 1 March 1969, W. W. Wirth genital capsule nearly hidden within the tip
(USNM). of the abdomen. The antennae are now
—
Paratypes. 3 (5,3 9 (including alloty- missing from the type as depicted in the
pe): same locality, date, collector, habitat as photographs, and the colors were said to be
holotype; 1 S, ANTIGUA: Dutchman Bay, faded, but the head is present, and the fron-
1 March 1969,—W. W. Wirth (all USNM). tal and facial shapes can be seen. The face
Etymology. The speciesWis named for is square, not higher than wide, the form
the collector, the late Willis Wirth ofthe previously cited for A. bredini Robinson
VOLUME NUMBER
99, 3 481
Figs. 1-7. Asyndetiis. 1-3, A. archboldi. 1, Genital capsule. 2, Antenna. 3, Head showing face and front.
4-6, A. wirthi. 4, Genital capsule. 5, Antenna. 6, Head showing face and front. 7.A. interruptus. head showing
face and front. 1, 4, 50 ixm scale. 2-5, Upper0.5 mm scale. 6, Lower0.5 mm scale. 7, Drawn from photograph
oftype specimen, seen from slightly above.
(1975). Asyndetus bredini is a synonym of widely. A female, that may be this species,
A. interruptus, and the material describedas has been seen from Quintana Roo, Mexico.
A. interruptus in 1975 is described here as Asyndetus interruptus is known from Flor-
a new species. ida, Cuba and Dominica.
Both Asyndetus wirthi and A. interruptus
are found along seashores of the Gulf of Acknowledgment
Mexico and Caribbean area, a habitat that
is common in the genus. The new species Gabriel Garcea G., at the Centro Oriental
is described strictly from Jamaica and An- de Ecosistemas y Bioversidad in Santiago
tigua, but it is presumed to occur more de Cuba, is thanked for the photographs of
482 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
W
the type specimen ofAsyndetus interruptus Oldroyd, H. 1964. The natural history offlies. W.
in Havana. Norton and Company, New York. 324 pp.
Robinson, H. 1964. A synopsisoftheDolichopodidae
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