A review of the genus Chrysotus (Diptera: Dolichopodidae) from Bermuda

9 Pages·1996·6.7 MB·

by  N E Woodley

PROC. ENTOMOL. SOC. WASH.
98(2), 1996, pp. 199-207
A REVIEW OF THE GENUS CHRYSOTUS (DIPTERA: DOLICHOPODIDAE)
FROM BERMUDA
NORMAN E. WOODLEY
Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Depart-
ment of Agriculture, %National Museum of Natural History, MRC 168, Washington, DC
20560, U.S.A.
Abstract.(cid:8212)The four species of the genus Chrysotus (Diptera: Dolichopodidae) found
in Bermuda are taxonomically reviewed. Chrysotus hilburni, new species is described,
males of C. bermudensis Johnson are described for the first time, and C. magnipalpus
Van Duzee, 1927 is a new synonym of C. crosbyi Van Duzee, 1924.
Key Words: Diptera, Dolichopodidae, Chrysotus, Bermuda
In a survey of the Diptera of Bermuda tropical Region. The taxonomy of the genus
(Woodley and Hilburn 1994), species as- has been based mainly on easily visible ex-
sociated with aquatic and marine littoral ternal morphology, without critical study of
habitats were a significant component of the the male genitalia, which are largely retract-
fly fauna, an observation not surprising for ed within the abdomen.
a small oceanic island archipelago with lit- The excellent key to Nearctic genera of
tle topography. The Dolichopodidae, with Dolichopodidae in Volume 1 of the Man-
the vast majority of its species being asso- ual of Nearctic Diptera (Robinson and
ciated with water habitats, were the fifth Vockeroth 1981) works well for the known
most speciose family of flies in Bermuda, Bermudan fauna. Most of the non-Chry-
with 12 genera and 15 species recorded. sotus dolichopodid species can easily be
Four of these belonged to the genus Chry- identified using Robinson(cid:8217)s (1964) synop-
sis of the fauna of southeastern North
sotus Meigen. Two are believed to be en-
demic, one of which is undescribed. The America.
other, Chrysotus bermudensis Johnson, was
KEY TO SPECIES OF CHRYSOTUS IN BERMUDA
known only from females prior to this
1. All coxae pale yellow, concolorous with femora
study. Thus, a brief review of the genus for
and tibiae; females with katepisternum and meron
Bermuda seems warranted to characterize
largely yellow; male antenna with basal flagel-
taxonomically the poorly known species lomere with deep apical notch in which the arista
that occur there. is inserted (Fig. 5) ...... C. hilburni, new species
(cid:8212) Middle and hind coxae dark, contrasting with
Chrysotus is a large genus of at least 270
pale yellow femora; females with katepister-
species found worldwide. Because individ-
num and meron dark; male antenna with at
uals are small in size and usually rather most a shallow apical notch (Fig. 3)
plain morphologically compared to many 2. Middle tibia with only a single anterodorsal
other dolichopodids (especially the fe- bristle near basal fourth; abdominal tergites
dark brown to black, sometimes with faint blu-
males), the genus has been relatively ne-
ish metallic reflections; male palpi greatly en-
glected. There are certain to be many un-
larged, flap-like, bright silvery white (Fig. 4)
described species, especially in the Neo- BPEL AURA ae oa Seed ceed tere C. crosbyi Van Duzee
200 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Ii ' y
Figs. 1-8. Male antennae of Chrysotus spp., lateral views. 1, C. bermudensis. 3, C. crosbyi. 5, C. hilburni.
7, C. picticornis. Male palpi of Chrysotus spp., lateral views. 2, C. bermudensis. 4, C. crosbyi. 6, C. hilburni.
8, C. picticornis.
Middle tibia with one anterodorsal and/or one posterior face, at most one or two enlarged
posterodorsal bristle near middle; abdominal setae near apex; male palpus with long, par-
tergites distinctly metallic green to bronzy; allel-sided apex more than twice as long as
male palpi not greatly enlarged, at most with a wide (Fig. 2); scutum and abdomen dark me-
projecting apex, white to yellowish, not silvery tallic green, less tomentose (more shiny) than
C. picticornis ....... C. bermudensis Johnson
. First antennal segment yellow; male fore femur
with row of uniform, ventrally directed setae
on posterior face, much longer than general Chrysotus bermudensis Johnson
vestiture; male palpus small, rounded, about as (Figs. 1, 2, 9)
wide as long (Fig. 8); scutum and abdomen
Chrysotus bermudensis Johnson, 1913: 446.
generally with distinct coppery reflections,
more tomentose (less shiny) than C. bermuden- Holotype 2: Bermuda (MCZ, examined).
SIS) A. EV eis cates C. picticornis Loew
Diagnostic description.(cid:8212)Male: Head
First antennal segment black; male front fe-
with frons metallic green, in some speci-
mur without differentiated row of setae on
VOLUME 98, NUMBER 2 201
mens with faint bluish reflections, moder- little shorter than in male; palpus simple,
ately shiny; eyes contiguous on face; setae ovoid, grayish with indistinctly yellower
of head black, except postocular row yellow margins. Length 1.5(cid:8212)2.3 mm.
on lower two-thirds; antenna (Fig. 1) black, Distribution(cid:8212)Known only from Ber-
first flagellomere wider than long, apex muda.
sharply rounded, arista inserted slightly lat- Specimens examined.~BERMUDA: | 2
eral to and above apex; palpus (Fig. 2) (holotype), 26.vii.1905, T. K[incaid] (MCZ);
whitish yellow, apex slightly darker yellow, 2 2 (paratypes), 30.vi.1905, T. K[incaid]
sharply tapered near base to parallel-sided (MCZ); 4 5, 1 2, St. Georges, 1-3.11.1934,
apical region that is more than twice as long A. L. Melander (USNM); 2 6, Smith(cid:8217)s Par-
as wide, apex rounded. Thorax with scutum ish, Spittal Pond, Malaise trap, 7.viii.1987,
bright green, with slight coppery reflections D. J. Hilburn (BNHM); 1 3,3 2, same data
in some specimens, thinly tomentose, pleu- but 12.viii.1987 (BNHM); 2 2, Smith(cid:8217)s Par-
ra dark and more densely tomentose; scutal ish, Spittal Pond, sweeping pond edge,
setae black, acrostichals biserial; scutellum 18.x1.1987, D. J. Hilburn, N. E. Woodley
with one strong pair of marginal setae, with (USNM); 1 2, Hamilton Parish, Shelly Bay,
one hair-like pair lateral to these. Legs with sweeping at edge of mangroves, 20.xi.1987,
front coxae except extreme bases pale yel- D. J. Hilburn, N. E. Woodley (USNM); 1 3
low, with yellow setae, mid and hind coxae same data, 31.v.1991, N. E. Woodley
dark; remainder of legs pale yellow except (USNM); 1 2, Southampton Parish Horse-
apical third to fourth of hind femur black, shoe Bay, 15.xi.1987, D. J. Hilburn, N. E.
and all tarsi slightly darkened apically; Woodley (USNM); 1 6, Paget Parish, Mal-
front femur with two to four slightly en- aise trap, 15.x.1987, D. J. Hilburn (BNHM);
larged posteroventral setae near apex, oth- 1 6, Paget Parish, Paget Marsh, 15.xi.1987,
erwise with uniform vestiture, hind femur D. J. Hilburn, N. E. Woodley (USNM); 1 &,
with two or three enlarged anteroventral se- same data, 3.vi.1991, N. E. Woodley
tae near apex; midtibia with one anterodor- (USNM); 6 3, 11 2, Devonshire Parish, De-
sal seta near base and one anterodorsal and vonshire Marsh, sweeping near water,
one posterodorsal seta near middle (the an- 20.xi.1987, D. J. Hilburn, N. E. Woodley
terior of these usually larger); tarsi unmod- (BNHM, USNM); 2 6, 2 2, same data,
ified. Wing with costal border of cell r, 2.0 30.v.1991, N. E. Woodley (USNM); 5 6, 1
times length of costal border of cell c; anal 2, Warwick Parish, Warwick Pond,
lobe evenly rounded; vein A, faint, fold- 3.vi.1991, N. E. Woodley (USNM).
like; calypter pale with pale yellow setae; Biology.(cid:8212)This species has been collect-
halter pale yellow, stem vaguely darker. ed in typical wetland habitats that dolicho-
Abdomen green (concolorous with scutum), podids frequent, especially pond margins
shiny with almost imperceptible tomentum, and marshes. It was also collected in a man-
setae black. Male terminalia (Fig. 9) with grove swamp.
hypandrial lobe short, triangular; epandrial Remarks.(cid:8212)In citing the type material
lobe short, broad, rounded apically; surstyli Johnson (1913) stated that the dates of col-
robust, slightly arcuate, apices convergent, lection were (cid:8220)June 20, July 26.(cid:8217) The ho-
each with a strong, peg-like seta and sharp lotype label is dated July 26, but the two
internal angle, appearing bifurcate; cercus paratypes are dated June 30. This was prob-
small, nearly triangular in outline. Length ably a typographical error in Johnson(cid:8217)s pa-
1.3-1.9 mm. per as the types were clearly labeled by
Female: Differs from male as follows: Johnson.
Head with eyes separated by face which is Chrysotus bermudensis keys to C. an-
nearly parallel-sided, with dense gray to- nulatus Van Duzee (known from the eastern
mentum; antenna with basal flagellomere a seaboard of the U.S., from Connecticut
202 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Figs. 9-12. Male hypopygia of Chrysotus spp., lateral views. 9, C. bermudensis, with inset showing dorsal
view of surstylus. 10, C. crosbyi. 11, C. hilburni. 12, C. picticornis. Abbreviations: aed, aedeagus; c, cercus;
epl, epandrial lobe; hypf, hypopygial foramen; hypl, hypandrial lobe; sur, surstylus.
south to Florida) in Robinson(cid:8217)s (1964) key Chrysotus crosbyi Van Duzee
to species from eastern North America. (Figs. 3, 4, 10)
Males of C. annulatus have an ovoid palpus
Chrysotus crosbyi Van Duzee, 1924: 43.
with a single conspicuous apical seta, and
Holotype 5: USA, Missouri, (cid:8220)(cid:8220)Colum-
very different terminalia with elongate
bus(cid:8221)(cid:8217) [sic; label reads Columbia] (CORN,
thorn-like surstyli and elongate cerci.
examined).
This species usually has a bright, shiny
Chrysotus magnipalpus Van Duzee, 1927:
green appearance, but some specimens may
2. Holotype ¢: Cuba, Havana (AMNH,
have coppery reflections. As with metallic
examined). NEw SYNONYMY.
coloration in other insects, some variation
is probably the result of differences in con- Diagnostic description.(cid:8212)Male: Head
ditions as individual specimens dry after with frons dark metallic violet, with faint
death. Also, care must be taken in observ- greenish or bronzy reflections in some spec-
ing setal color, as pale setae often appear imens, moderately shiny; eyes nearly con-
black in certain lights. tiguous on face, face narrower medially
VOLUME 98, NUMBER 2 203
than the diameter of an adjacent ommatid- dense gray tomentum covering evident blu-
ium; setae of head black, except some of ish metallic coloration; antenna with basal
postocular row yellow on lower half; anten- flagellomere a little shorter than in male,
na (Fig. 3) black, first flagellomere broader much more shallowly notched; palpus
than long, apex slightly notched, arista in- much smaller than in male, simple, ovoid,
serted at base of notch; palpus (Fig. 4) en- dark. Front coxae sometimes more conspic-
larged, bright silvery white, nearly ovoid, uously yellow than in male. Length 1.3(cid:8212)1.7
margins broadly rounded. Thorax with scu- mm.
tum dark bronzy green, thinly tomentose, Distribution(cid:8212)Known from the Eastern
scutellum a little more bluish in most spec- United States (Georgia, Missouri, North
imens; pleura dark and more densely to- Carolina), Bermuda, Cuba, and Puerto
mentose; scutal setae black, acrostichals Rico. Robinson (1977) has seen specimens
biserial; scutellum with one strong pair of from Brazil that are possibly conspecific.
marginal setae, with one small, hair-like Specimens examined.mBERMUDA: 22
pair lateral to these. Legs with front coxae 6, 14 2, Devonshire Parish, Devonshire
yellowish with some irregular dark obfus- Marsh, sweeping near water, 20.x1.1987, D.
cation, usually contrasting to the more uni- J. Hilburn, N. E. Woodley (USNM); 8 6,
formly darkened mid and hind coxae, with same data, 30.v.1991, N. E. Woodley
mostly dark setae; remainder of legs yel- (USNM); 2 6, 13 2, Smith(cid:8217)s Parish, Spittal
lowish except dorsal surfaces of femora and Pond, sweeping pond edge, 18.x1.1987, D.
apex of hind femur may be nebulously J. Hilburn, N. E. Woodley (USNM); 6 ¢,
darkened in some specimens; front femur 7 2, Hamilton Parish, Shelly Bay Beach,
with one slightly enlarged posteroventral 31.v.1991, N. E. Woodley (USNM); 10 d,
seta near apex, otherwise with uniform ves- 3 2, Paget Parish, Paget Marsh, 3.vi.1991,
titure, hind femur with two or three en- N. E. Woodley (USNM); 1 6d, Hamilton
larged anteroventral setae near apex; middle Parish, Walsingham Bay, 31.vi.1991, W. N.
tibia with one anterodorsal seta near basal Mathis (USNM); 1 6, 1 2, Warwick Par-
third, none near middle; tarsi unmodified. ish, Warwick Pond, 3.vi.1991, N. E. Wood-
Wing with costal border of cell r, 1.9(cid:8212)2.0 ley (USNM). Additional specimens from
times length of costal border of cell c; anal Bermuda were examined from BNHM that
lobe evenly rounded; vein A, present only were previously recorded as C. magnipal-
near base as a faint fold; calypter dark with pus (Woodley and Hilburn 1994: 23). Also,
dark yellow setae; halter pale yellow, stem 2 6, UNITED STATES: North Carolina,
vaguely darker. Abdomen dark brown to Durham Co., 25.v.1960, H. Robinson
black with vague metallic blue to violet re- (HRC).
flections, very thinly tomentose, setae Biology.(cid:8212)This species is quite common
black. Male terminalia (Fig. 10) with hy- in freshwater marsh and pond habitats, and
pandrial lobe short, triangular; epandrial some specimens were collected in the man-
lobe short, broad, abruptly tapered to apex, grove swamp at Shelly Bay.
with a stout apical seta; surstyli robust, Remarks.(cid:8212)I initially identified this spe-
slightly arcuate, apices convergent and each cies as Chrysotus magnipalpus (Woodley
tapered to a sharp apex; cercus small, long and Hilburn 1994) because Bermuda spec-
ovoid with a squarish angle near base. imens tend to have fore coxae that are paler
Length 1.2(cid:8212)1.5 mm. than the posterior two pairs, sometimes
Female: Differs from male as follows: quite yellow in females. Thus, they do not
Head with frons tending to be more bluish fit couplet 9 in Robinson(cid:8217)s (1964) key very
than in male; eyes separated by face which well. Additionally, no mention is made in
has margins convergent to medial trans- the key of the unique form of the palpi,
verse ridge, then slightly divergent, with only that they are (cid:8220)(cid:8216)enlarged, nearly as long
204 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
as height of face(cid:8217)? (Robinson 1964: 131). I yellow; front femur with two or three
matched the Bermuda material to a speci- slightly enlarged posteroventral setae near
men in the USNM identified as C. magni- apex, otherwise with uniform vestiture,
palpus from Puerto Rico, and confirmed its hind femur with two or three enlarged an-
identity by examining the holotype. Van teroventral setae near apex; middle tibia
Duzee (1927: 2) described the fore coxae with only one anterodorsal seta on basal
of C. magnipalpus as (cid:8220)(cid:8216)mostly yellow.(cid:8221) At third; tarsi unmodified. Wing with costal
that time I made the mistaken assumption border of cell r, 2.1(cid:8212)2.3 times length of cos-
that Van Duzee would not have described tal border of cell c; anal lobe evenly round-
the same species twice in the space of three ed; vein A, faint, present only as a weak
years. However, I recently examined mate- fold; calypter pale with pale yellow setae;
rial of C. crosbyi, including its holotype, halter pale yellow. Abdomen brownish,
and found them to be conspecific with C. with faint green metallic reflections, weakly
magnipalpus. It seems that for some wide- shiny with inconspicuous tomentum, setae
spread dolichopodids some color features dark. Male terminalia (Fig. 11) with hy-
are variable and therefore unreliable for pandrial lobe extremely short, triangular;
keys, such as coxal color in this species. epandrial lobe very short, bluntly rounded
Color variation was also found in Bermu- apically, with short, stout apical seta; sur-
dan material of Diaphorus contiguus A\- styli with inner margins expanded, apices
drich (Woodley and Hilburn 1994), which nearly parallel in dorsal view, each with
would not key out properly in Robinson(cid:8217)s one or two tiny subapical setae and short,
(1964) key to that genus. stout, slightly curved apical seta; cercus
small, nearly triangular in outline. Length
Chrysotus hilburni Woodley,
1.1-1.3 mm.
NEW SPECIES
Female: Differs from male as follows:
(Figs. 5, 6, 11)
Head with eyes separated by face which has
Diagnostic description.(cid:8212)Male: Head convergent margins in upper half, nearly
with frons metallic green, thinly tomentose, parallel-sided in lower half, with dense gray
moderately shiny; eyes nearly contiguous tomentum; antenna with basal flagellomere
on face, medial part of face much narrower shorter than in male, only shallowly
than an adjacent ommatidium; setae of head notched; palpus simple, ovoid, yellow. Tho-
black, except postocular row yellow on rax with lower parts of pleura pale yellow.
lower half; antenna (Fig. 5) with scape and Abdomen with sternites pale yellow.
pedicel yellow, flagellum dark, first flagel- Length 1.2(cid:8212)1.6 mm.
lomere longer than high, apex deeply Distribution(cid:8212)Known only from Ber-
notched, arista inserted at base of notch; muda.
palpus (Fig. 6) whitish yellow, slightly Specimens examined.(cid:8212)BERMUDA:
club-shaped, apex with single, long, stout Holotype 6, allotype 2, 4 ¢6, 2 2 para-
seta. Thorax with scutum bright green, with types, Devonshire Parish, Devonshire
slight coppery reflections in most speci- Marsh, sweeping near water, 20.x1.1987, D.
mens, thinly tomentose, scutellum more J. Hilburn, N. E. Woodley (USNM). Addi-
bluish in most specimens; pleura yellowish tional paratypes: 3 ¢, 7 ¢, same data,
brown, non-metallic and more densely to- 30.v.1991, N. E. Woodley (USNM, BNHM,
mentose; scutal setae brownish, acrostichals CNC); 2 6, 2 &, Hamilton Parish, Trott(cid:8217)s
biserial; scutellum with one strong pair of Pond, in grass, 29.xi.1966 (BNHM); 7 6,
marginal setae, without hair-like pair lateral 9 2, Paget Parish, Paget Marsh, 3.vi.1991,
to these. Legs including coxae entirely pale N. E. Woodley (USNM, BNHM, CNC).
yellow, tarsi with apical tarsomere slightly Biology.(cid:8212)This species has been taken
darkened; femoral and tibial setae primarily only at marshy habitats in Bermuda. It
VOLUME 98, NUMBER 2 205
seems to be the least common species of slightly lateral to the apex; palpus (Fig. 8)
Chrysotus on the islands. pale yellow, small ovoid, with two or three
Remarks.(cid:8212)Chrysotus hilburni is quite small marginal setae near apex. Thorax
similar to C. furcatus Robinson from the with scutum cupreous green, moderately to-
eastern United States (Iowa and New York mentose, pleura dark and densely tomen-
south to Florida) but differs in a number of tose; scutal setae black, acrostichals biseri-
respects. In C. furcatus the frons is bluish al; scutellum with one strong pair of mar-
to violet in both sexes; the basal antennal ginal setae, with one hair-like pair lateral to
flagellomere in the male has the lobes be- these. Legs with front coxae yellow, with
yond the notch much more dissimilar in yellow setae, mid and hind coxae dark; re-
length, the lower being much longer than mainder of legs yellow except apical fourth
the upper; and the pleura of the female are of hind femur darkened, and all tarsi be-
completely dark. The male genitalia of C. coming darkened apically; front femur with
hilburni differ from those of C. furcatus by posteroventral row of uniform setae, pale
having a very short hypandrium and basally becoming dark and stouter near
straighter, more slender surstyli (viewed lat- middle and continuing to apex; hind femur
erally). The male palpi in the two species with row of three to five enlarged antero-
are very similar, with a characteristic apical ventral setae apically and some denser pale
seta. This may be a synapomorphy for a pubescence at basal third; middle tibia with
subgroup of Chrysotus that includes these one anterodorsal seta near base and one an-
two species, C. annulatus, and probably terodorsal and one posterodorsal seta near
others. middle; tarsi unmodified. Wing with costal
I take much pleasure in naming this spe- border of cell r, 2.1(cid:8212)2.3 times length of cos-
cies after Daniel J. Hilburn. While appoint- tal border of cell c; anal lobe more devel-
ed as Plant Protection Officer in Bermuda oped than in other Bermuda species; vein
he initiated a modern faunal survey of the A, well delineated on basal half; calypter
islands that resulted in a much greater un- pale with brownish setae; halter yellow.
derstanding of the insects inhabiting this Abdomen cupreous green (concolorous
oceanic archipelago. with scutum), sheen dulled by thin tomen-
tum, setae black. Male terminalia (Fig. 12)
Chrysotus picticornis Loew with hypandrial lobe short, triangular; epan-
(Figs. 7, 8, 12) drial lobe short, broad, triangular apically
in lateral view, with long apical seta; sur-
Chrysotus picticornis Loew, 1862: 214.
styli elongate, slender, apices divergent,
Type(s) 6: USA, Illinois (MCZ, not ex-
each with two or three small subapical setae
amined).
and short, stout slightly curved apical seta;
Diagnostic description.(cid:8212)Male: Head cercus small, nearly triangular in outline.
with frons metallic cupreous green, finely Length 1.4(cid:8212)2.1 mm.
shagreened so as to appear only weakly Female: Differs from male as follows:
shiny; eyes nearly contiguous on face, face Head with eyes separated by face which is
extremely narrow medially, much less than nearly parallel-sided, with dense brownish
the width of an adjacent ommatidium; setae gray tomentum; antenna with basal flagel-
of head black, except postocular row yel- lomere a little shorter than in male; palpus
lowish white on lower two-thirds or more; simple, ovoid, dirty yellowish. Front femur
antenna (Fig. 7) with scape and basal part without posteroventral row of setae, only
of pedicel yellow, sometimes lower basal two or three enlarged setae near apex; hind
angle of first flagellomere yellowish, re- femur with shorter, more uniform vestiture.
mainder black; first flagellomere about as Length 1.5(cid:8212)2.1 mm.
long as high, apex rounded, arista inserted Distribution.(cid:8212)Widespread in the United
206 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
States from Massachusetts south to Califor- species is easily identifiable using Robin-
nia and Florida, and Mexico (Chiapas). son(cid:8217)s (1964) key.
Other Neotropical records probably refer to
other species (Robinson, 1967). ACKNOWLEDGMENTS
Specimens examined(cid:8212)BERMUDA: 6
I thank once again all those persons cited
6, 4 ¢&, Smith(cid:8217)s Parish, Spittal Pond, in Woodley and Hilburn (1994) for facilitat-
sweeping pond edge, 18.x1.1987, D. J. Hil- ing the study of the Diptera of Bermuda.
burn, N. E. Woodley (USNM); 1 ¢, same Dan Hilburn also energetically facilitated my
data, 29.v.1991, N. E. Woodley (USNM); 1 work on Bermuda flies in many ways. I wish
6, 6 ¢, Hamilton Parish, Shelly Bay, to thank the Bermuda Natural History Mu-
sweeping at edge of mangroves, 20.x.1987, seum (BNHM); Jeffrey Cumming, Canadian
D. J. Hilburn, N. E. Woodley (USNM); 2 National Collection, Agriculture Canada
$, 5 2, Devonshire Parish, Devonshire (CNC); David Furth, Museum of Compara-
Marsh, sweeping near water, 20.x1.1987, D. tive Zoology, Harvard University (MCZ);
J. Hilburn, N. E. Woodley (USNM); 36 6, David Grimaldi, American Museum of Nat-
30 2, same data, 30.v.1991, N. E. Woodley
ural History (AMNH); and E. R. Hoebeke,
(USNM); 12 36, 2 2, Devonshire Parish, Cornell University Insect Collection
Cloverdale, 29.v.1991, W. N. Mathis (CORN) for loaning holotypes and other
(USNM); 3 3, 2 &, Devonshire Parish, material important to this study. Other spec-
Outerlea Farm, 2.vi.1991, W. N. Mathis imens are in the National Museum of Nat-
(USNM); 2 3, 1 ¢&, Paget Parish, Paget
ural History, Smithsonian Institution
Marsh, 15.xi.1987, D. J. Hilburn, N. E. (USNM). Harold Robinson provided valu-
Woodley (USNM); 8 6, 6 @, same data, able discussion about some of the species
3.vi.1991, N. E. Woodley (USNM); 1 4,
discussed in this paper, loaned material from
Paget Parish, Hungry Bay, beach,
his collection (HRC), and critically read the
2.vi.1991, W. N. Mathis (USNM); 8 6, 14
manuscript. I also thank Brian Brown,
2, Warwick Parish, Warwick Pond, Wayne Mathis, Allen L. Norrbom, and Da-
3.vi.1991, N. E. Woodley (USNM). Addi- vid R. Smith for reviewing the manuscript.
tional Bermuda material has been examined
that is now in BNHM and MCZ (Woodley LITERATURE CITED
and Hilburn 1994). Also, extralimital ma-
Johnson, C. W. 1913. The Dipteran fauna of Bermuda.
terial of C. picticornis was examined in the
Annals of the Entomological Society of America
USNM collection.
6: 443-452.
Biology.(cid:8212)In my experience this is the Loew, H. 1862. Diptera Americae septentrionalis in-
most common species of Chrysotus in Ber- digena. Centuria secunda. Berliner Entomologis-
muda. It is frequent virtually everywhere che Zeitschrift 6: 185-232.
Robinson, H. 1964. A synopsis of the Dolichopodidae
there is pond or marshy habitat, as well as
(Diptera) of the southeastern United States and ad-
in mangrove areas.
jacent regions. Miscellaneous Publications of the
Remarks.(cid:8212)Robinson (1967) found that Entomological Society of America 4: 103-192.
what had been called C. picticornis from . 1967. New species of Dolichopodidae from
Neotropical localities was actually a com- the United States and Mexico (Diptera). Proceed-
ings of the Entomological Society of Washington
plex of three species. He cited variation in
69: 114-127.
the hypopygial morphology of one of the
. 1977. A new species of Dominicomyia from
similar species, C. mexicanus Robinson, so Brasil (Diptera: Dolichopodidae). Proceedings of
it is quite possible that even more species the Entomological Society of Washington 79:
are involved. The Bermuda material clearly 310-312.
Robinson, H. and J. R. Vockeroth. 1981. Dolichopod-
conforms to Robinson(cid:8217)s concept of C. pic-
idae, Chapter 48, pp. 625-639. In McAlpine, J. F,
ticornis with its distinctive vestiture of the
B. V. Peterson, G. E. Shewell, H. J. Teskey, J. R.
hind femur and hypopygial structure. This Vockeroth, and D. M. Wood, eds., Manual of Ne-
VOLUME 98, NUMBER 2
207
arctic Diptera. Volume 1. Agriculture Canada, Ot- 1927. New Dolichopodidae from the West
tawa. i(cid:8212)vi; 1-674. Indies. American Museum Novitates 262: 1(cid:8212)10.
Van Duzee, M. C. 1924. A revision of the North Woodley, N. E. and D. J. Hilburn. 1994. The Diptera
American species of the dipterous genus Chryso- of Bermuda. Contributions of the American En-
tus. Bulletin of the Buffalo Society of Natural Sci- tomological Institute 28(2): 1-64.
ences 13: 1-53.