Table Of ContentPROC. ENTOMOL. SOC. WASH.
96(3), 1994, pp. 466-470
MICROPEZA CORRIGIOLATA A EURASIAN STILT-LEGGED FLY
(L.),
(DIPTERA: MICROPEZIDAE) NEW TO NORTH AMERICA:
REDESCRIPTION, GEOGRAPHIC DISTRIBUTION, AND BIONOMICS
E. Richard Hoebeke and A. G. Wheeler, Jr.
Department ofEntomology, Cornell University, Ithaca, New York 14853, and Bureau
ofPlant Industry, Pennsylvania DepartmentofAgriculture, Harrisburg, Pennsylvania 17110.
Abstract.—ThecommonandwidespreadEurasianmicropezidflyMicropezacorhgiolata
(L.) is reported for the first time from North America. Adults were collected in late June
1993 in New Brunswick, Canada. This adventive species is redescribed, and habitus
photographs ofthe male and female are provided to facilitate identification. Notes on its
geographic distribution, bionomics, and ecology are provided. A key to the species of
Micropeza ofCanada and Alaska (Merritt and Peterson 1976) is modified to include M.
corrigiolata.
Key Words: Diptera, Micropeza corrigiolata, stilt-legged fly, North America, distribu-
tion, bionomics
During our continuing search for immi- parafrontal area, epicephala, and ocellar
grant insects in eastern North America, we spot; mesofrons black; face and bucca pale
collected ten specimens ofa small stilt-leg- yellowtoalmost white; paracephalaand oc-
ged fly in New Brunswick, Canada, that ciput black with oral margin pale yellow;
proved to be the Palearctic Micropeza cor- frontale not differentiated; distal portion of
rigiolata (L.), family Micropezidae. This proboscis pale yellow, proximal portion
species has not been recorded before in black; palpus dark brown to black; antenna
North America. black, arista white, brownish at extreme
base; inner- and outer-vertical bristles, and
Diagnostic Features
postvertical bristles black.
The Canadian specimens agree with the Thorax dull black, except presternum
description ofA/, corrigiolataandkeyreadi- whitish, distinctly cinereous-pruinose;
ly to that species in the European literature meso- and metasternum with dark bristles
(Czemy 1930, Shtakel'berg 1988, Rohacek or bristlelike setae; strong bristles ofthorax
and Bartak 1990). For final identification, black. Haltere yellow. Wing brownish hy-
comparative material of Micropeza corri- aline, veins brown. Procoxa yellow; meso-
giolatafrom Europewereobtainedfromthe and metacoxa brownish; femur yellow-or-
National Museum of Natural History. ange, except preapical ring (annulus) and
Smithsonian Institution, Washington, D.C. apices ofmeso- and metafemora brownish;
Terminology used in the description below profemurwith apical half, andall tibiaeand
follows that of Merritt (1971), and Merritt tarsi brownish. Legs clothed with black se-
and James (1973). tae and bristles.
Redescription. Male (Figs. 1, 2): Head Abdomen (Fig. 2) mostly black; tergites
glossyandpolished,mainlyblack, including narrowly pale yellow to white at posterior
VOLUME 96, NUMBER 3 467
Figs. 1-3. Micropeza corrigiolata. 1. Male habitus, lateral aspect. 3, Female habitus, lateral aspect. 2, Male
abdomenand genitalstinictures, lateralaspect. Collectedat St. John, St. John Co., New Brunswick, Canada, 24
June 1993.
and lateral margins; stemitesalso brownish Discussion
toblackexcept forpalelateral margins. Ter-
minalia (Fig. 2) brown to black. Sternite 5 An important early work on the taxon-
without pair oflobes orclaspers [= abdom- omy ofthe North American Micropezidae
inal clasping organ: "Kopulationsgabel" of is that of Cresson (1938), who recognized
Emden and Hennig (1970)]. Abdomen ci- eight Nearctic species of the genus Micro-
nereous-pruinose, except for ninth tergite peza (subgenus Micropeza) and divided
more or less polished. Length 4.5-5.0 mm. them intothree speciesgroups(corrigiolata,
Female(Fig. 3): Similar to male in most turcana. and nitidor groups). Ten Nearctic
respects, but somewhat larger. Ovipositor species of Micropeza {Micropeza) are now
glossy black, slender, tapered towards apex. recognized, distributed chiefly in western
Length 5.0-7.0 mm. North America and ranging from the north-
468 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OFWASHINGTON
em Great Plains southward into Mexicoand densely greyish pruinose, with distinct vittae
the Neotropical Region (Merritt and James (Fig. 6) . . . chillcotti Memtt and Peterson (1976)
Fifth stemite ofmale modified into clasping
1973, Steyskal 1987).
organ, directedanteriorlyas a pronglike, dig-
InadditiontobeingtheonlyeasternNorth
itateprocess(Figs.7,9,11);malesurstylisim-
AmericanMicropeza, M. corrigiolataiseas- ple and reduced in size. Head and mesonotal
ily distinguished from the other Nearctic pattern not as above 6
members ofthe genus by the lack ofan ab- (Couplets 6 and 7 unmodified).
dominal claspingorgan in the male (all oth-
Geographic Distribution
ers have the fifth abdominal stemite with a
well-developedpairoflobesorclaspers)and Micropeza corrigiolata is widely distrib-
themainlyblackcoloration(mostotherspe- utedthroughoutallpartsofEurope, Turkey,
cieshave variablecolorpatternsofthe head and also vast areas ofthe European part of
and thorax). the former Soviet Union including Estonia,
Merritt and Peterson (1976) provided a Latvia, Lithuania, Russia, Byelorussia,
synoptic review of the micropezid species Ukraine, and Moldavia (Soos 1984). In
in Canada and Alaska, with keys, illustra- North America, it is known only from two
tions, and descriptions offour new species. localities in New Brunswick, Canada: St.
They did not treat M. corrigiolata. Had John Co., St. John, 24-25 June 1993,
specimens ofthis rather distinctive species sweeping vegetation, 4 males, 5 females;
been housed inthevariousinstitutionalcol- Westmorland Co., Moncton, 25 June 1993,
lectionstheystudied, theywouldsurelyhave sweepingvegetation, male. Specimensare
1
noted and recorded it from Canada. deposited in the Cornell University Insect
As a result oftheir extensive study. Mer- Collection (Ithaca, NY) and the United
ritt and Peterson (1976) recorded four spe- StatesNational Museum ofNatural History
cies oiMicropeza from Canada and Alaska, (Washington, DC).
including the newly described M. chillcotti. Weobservedandcollectedthesefliesfrom
All are known from states and provinces low-growing vegetation alongside several
west ofthe Mississippi River in the United warehouse buildings near a railroad yard
States, and the 90th Meridian in Canada. and along tracks at St. John, and on vege-
The following changes should be made to tation at another railroad right-of-way at
the Merritt and Peterson (1976) key to spe- Moncton. Flies were quite abundant at the
ciesofMicropeza (couplets 5-7. p. 1490) to two locations in St. John.
include M. corrigiolata. Figure numbers
printedin boldface typereferto figurespub- Bionomics
lished with the original key. Adults ofM. corrigiolata are common in
(Couplets 1^ unmodified). habitats with leguminous plants, and are
5. Fifth stemite ofmale eitherdirected posteri- usuallyobservedon vegetation indampand
orly and apically expanded into platelike shady places, in meadowsand fields, resting
structure,ormodifiedmtoclaspingorgan,di- and running on the upper surface offoliage
rectedanteriorlyaspronglike,digitateprocess
ofbushes and other herbaceous plants (Ro-
5a
Fifthstemiteofmaleentirelyunmodified(no hacek and Bartak 1990). While resting or
platelike structure or clasping organ) (Fig. 2) running on foliage with wings folded over
corrigiolata (L.) their abdomens, adults rub and wave their
5a. Fifthstemiteofmaledirectedposteriorly,and foretarsi in front of them (personal obser-
expanded into a platelike stmcture as in Fig.
5; male surstyli modified mto large cupped vation), a habit also observed for other mi-
structures(Fig.5). Headwithabroad U-shaped cropezids (Berg 1947). Flies may occur in
marking (Fig. 6). Mesonotum blackish and great numbers, especially on legumes, from
:
VOLUME NUMBER
96, 3 469
the beginning of June until the middle of ofM. corrigiolata from Europe and for his
Julyin Europe(Miiller 1957). In Britain and review ofthe manuscript.
western Europe, this species is not uncom-
mon in gardens, where it likely breeds in Literature Cited
compost heaps(Chinery 1986). Seguy(1951)
Berg.CO. 1947. Biologyandmetamorphosisofsome
stated that adults ofAf. corrigiolataare pre-
SolomonIslandsDiplera.Part1: Micropezidaeand
dacious ("zoophagous") on other small in- Neriidae. Occasional Papers of the Museum of
sects; this predatory habit of micropezids Zoology, University ofMichigan 503: 1-14.
has been subsequently mentioned by such Chinery, M. 1986. Collins Guide to the Insects of
workers as Oldroyd (1964: 177) and Colyer BritainandWesternEurope.Collins,London. 320
(1968: 200). Merritt and James (1973). pp.
Colyer,C.N. 1968. Fliesofthe Bntish Isles. 2nded.
however, proposed that adults feed on ex- F. Wame, London. 384 pp.
crement, carrion, and putrefied fruit, based Cresson. E. T., Jr. 1938. The Nenidae and Micro-
on their sponging mouthparts. pezidae of America north of Mexico (Diptera).
LarvaeofA/, corrigiolatahavebeenreared Transactionsofthe American Entomological So-
ciety 64: 293-366.
from root nodules of field pea (Pisum ar- Czemy, L. 1930. 42a.Tylidae und42b. Nenidae. //;
venseL.). red clover(TrifoliunipratenseL.). Lindner, E., ed.. Die Fliegen der Palaearktischen
and alfalfa (Afedicago saliva L.) in Europe Region 5: 1-18.
(Muller 1957, Ferrar 1987). Ahhough this Emden, F. van and W. Hennig. 1970. [Chapter) 21.
species has not been specifically recorded as Diptera. pp. 130-141. In Tuxen. S. L.. ed., Tax-
a pest, its mere abundance at times may be oMnuonmkissgtaa'rsd,GlCoospseanrhyagoefn.Genitalia in Insects.
detrimentaltothegrowthoflegumes(Ferrar Ferrar, P. 1987. AGuidetothe BreedingHabitsand
1987). Eggsarepresumably laidbeneath the ImmatureStagesofDipteraCyclorrhapha(Part 1
soil surface, and upon hatching, the larvae Text). E.J. Brill/ScandinavianSciencePress, Lei-
begintoattackfresh, healthynodules(never den. 478 pp.
decaying ones). They tunnel into nodules, Merritt. R. W. 1971. New and little known Micro-
pezidae from the western L'nited States. Pan-Pa-
hollowing them out, until only an empty cific Entomologist 47: 179-183.
shell remains. Fully fed third-instar larvae Merriu. R. W. and M. T. James. 1973. The Micro-
burrow about 30 cm into the soil to over- pezidaeofCalifornia(Diptera).BulletinoftheCal-
winter. Pupation occurs in the soil in spring ifornia Insect Survey 13: 1-27.
(Muller 1957, Ferrar 1987). A single gen- Merritt. R. W. and B. V. Peterson. 1976. A synopsis
oftheMicropezidae(Diptera)ofCanadaandAlas-
eration is produced annually. ka,withdescriptionoffournewspecies.Canadian
The egg, larval stages (first, second, and Journal ofZoology 54: 1488-1506.
third instars), and puparium are described Muller. H. 1957. Leguminosenknollchen als Nah-
in detail and illustrated by Muller (1957). rungsquelle heimischer Micropezidae- (Tylidae-)
Larven (Diptera): Zur Morphologic und Biologic
Ferrar (1987: 220), however, suggested that
derbisherLInbekanntenLarvevonMicropezacor-
Miiller's description ofthe first instarofM. rigiolata L. (Tylos corngwlatus L.). Beitrage zur
corrigiolata does not apply to a micropezid. Entomologie 7: 247-262.
Steyskal(1964)presentedakeytotheknown Oldroyd, H. O. 1964. The Natural History ofFlies.
third-instarlarvae ofMicropezidae. includ- W. W. Norton. New York. 324 pp.
ing M. corrigiolata. Rohacek. J. and M. Bariak. 1990. Micropezidae
(Diptera) of Czechoslovakia. Casopis Slezskeho
Muzea, Opava (Ser. A) 39: 97-1 11.
Acknowledgments
Seguy. E. 1951. Atlas des Dipteres de France, Bel-
We thank Allen L. Norrbom (Systematic gique-Suisse.ILDevelopmentetBiologic. Brachy-
Entomology Laboratory, L^SDA-ARS. % c^res II.—Siphonapt^res. N. Boubee, Paris. 185
pp.
U.S. National Museum ofNatural History, ShtakePberg, A. A. 1988. Family Micropezidae, p.
Washington, DC) for the loan ofspecimens 179.InBei-Bienko,G.Ya..ed..KevstotheInsects
470 PROCEEDINGS OFTHE ENTOMOLOGICALSOCIETY OF WASHINGTON
ofthe European Part of the USSR. Volume V: tera),includingtwospeciesthatboreingingerroots.
Diptera and Siphonaptera, Part II. [xxii] + 1505 Annals ofthe Entomological Society ofAmerica
PP.- —57: 292-296.
Soos, A. 1984. Family Micropezidae (Tylidae), pp. . 1987. Micropezidae. pp. 761-767. In
19-24. In Soos. A., ed.. Catalogue ofPalaearctic McAlpine. J. P.. et al., eds.. Manual ofNearctic
Diptera. Vol. 9:Micropezidae-.'\gromyzidae. El- Diptera, Vol. 2. Agnculture Canada, Monograph
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Steyskal, G. C. 1964. Larvae ofMicropezidae(Dip-
