Worldwide spread of the Argentine ant, Linepithema humile (Hymenoptera: Formicidae)

Article (PDF Available)inMyrmecological News 12:187-194 · October 2009with 1,802 Reads
Abstract
The Argentine ant, Linepithema humile (MAYR, 1868), originally from subtropical South America, is an important pest in many parts of the world. To evaluate its worldwide distribution and potential for further spread, we mapped records of L. humile from > 2100 sites. Because several South and Central American Linepithema species have been often mis-identified as L. humile, we excluded all unconfirmed South and Central American records. We documented the earliest known L. humile records for 95 geographic areas (countries, island groups, major islands, and US states), including several for which we found no previously published records. We could not confirm any L. humile records from several South and Central American countries with published reports. Most records of L. humile come from the subtropics, particularly from regions with Mediterranean-like climates (i.e., warm dry summers and cool moist winters), including its native range in South America and exotic populations in Cali-fornia, the Mediterranean, southern Africa, Australia, New Zealand, and Japan. In more humid subtropical areas, such as the southeast US, L. humile rarely dominates outside urban areas. In tropical latitudes, L. humile dominates only at higher elevations, most notably in Hawaii. In temperate areas, L. humile is almost exclusively an indoor pest.
Figures - uploaded by Xavier Espadaler
Author content
All content in this area was uploaded by Xavier Espadaler
Myrmecological News 12 187-194 Vienna, September 2009
Worldwide spread of the Argentine ant, Linepithema humile (Hymenoptera: Formicidae)
James K. WETTERER, Alexander L. WILD, Andrew V. SUAREZ, Núria ROURA-PASCUAL & Xavier ESPADALER
Abstract
The Argentine ant, Linepithema humile (MAYR, 1868), originally from subtropical South America, is an important pest
in many parts of the world. To evaluate its worldwide distribution and potential for further spread, we mapped records
of L. humile from > 2100 sites. Because several South and Central American Linepithema species have been often mis-
identified as L. humile, we excluded all unconfirmed South and Central American records. We documented the earliest
known L. humile records for 95 geographic areas (countries, island groups, major islands, and US states), including
several for which we found no previously published records. We could not confirm any L. humile records from several
South and Central American countries with published reports.
Most records of L. humile come from the subtropics, particularly from regions with Mediterranean-like climates (i.e.,
warm dry summers and cool moist winters), including its native range in South America and exotic populations in Cali-
fornia, the Mediterranean, southern Africa, Australia, New Zealand, and Japan. In more humid subtropical areas, such as
the southeast US, L. humile rarely dominates outside urban areas. In tropical latitudes, L. humile dominates only at higher
elevations, most notably in Hawaii. In temperate areas, L. humile is almost exclusively an indoor pest.
Linepithema humile has already spread to most subtropical lowland regions with Mediterranean-like climates, but is not
known yet from most tropical highland areas with suitable climates. In the past, L. humile probably arrived in tropical
regions by sea accompanying human commerce and had to survive coastal lowland conditions before spreading to higher,
cooler elevations. Nowadays air travel allows L. humile to stowaway in cargo delivered almost anywhere in the world.
Therefore, a wider spread of this pest is expected in the future.
Key words: Biogeography, biological invasion, exotic species, Formicidae, invasive species.
Myrmecol. News 12: 187-194 (online 8 June 2009)
ISSN 1994-4136 (print), ISSN 1997-3500 (online)
Received 30 August 2008; revision received 3 March 2009; accepted 4 March 2009
Prof. Dr. James K. Wetterer (contact author), Wilkes Honors College, Florida Atlantic University, 5353 Parkside Drive,
Jupiter, FL 33458, USA. E-mail: wetterer@fau.edu
Dr. Alexander L. Wild & Prof. Dr. Andrew V. Suarez, Department of Entomology, University of Illinois, 320 Morrill Hall,
505 S. Goodwin Ave., Urbana, IL 61801, USA. E-mail: alexwild@illinois.edu; avsuarez@life.uiuc.edu
Dr. Núria Roura-Pascual, Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Pri-
vate Bag X1, Matieland 7602, South Africa. E-mail: nrourapascual@gmail.com
Prof. Dr. Xavier Espadaler, 2. Ecology Unit, Universidad Autónoma de Barcelona, E-08193 Bellaterra, Spain. E-mail:
xavierespadaler@gmail.com
Introduction
Several exotic ant species are known to have substantial
ecological impacts. When these species invade, they can
disrupt the indigenous invertebrate fauna and transform
the native biotic community. Among the most destructive
invasive ants are the red imported fire ant, Solenopsis invicta
BUREN, 1972 (ALLEN & al. 2004), the little fire ant, Was-
mannia auropunctata (ROGER, 1863) (WETTERER & PORTER
2003), the long-legged ant Anoplolepis gracilipes (SMITH,
1857) (WETTERER 2005), the African big-headed ant, Phei-
dole megacephala (FABRICIUS, 1793) (WETTERER 2007),
and the Argentine ant, Linepithema humile (MAYR, 1868)
(VEGA & RUST 2001).
Linepithema humile (Figs. 1 - 4) has negative impacts
on many other animals, both vertebrates and invertebrates
e.g., VEGA & RUST 2001, WETTERER & al. 2001, SUAREZ
& al. 2005). In addition, L. humile can be a significant agri-
cultural pest, enhancing populations of Hemiptera (VEGA &
RUST 2001). Hemiptera cause damage by sapping plants
of nutrients and increasing the occurrence of diseases, in-
cluding viral and fungal infections.
(
Linepithema humile is native to the Paraná River drain-
age area of subtropical Argentina, Brazil, Paraguay, and
Uruguay, which has a Mediterranean-like climate, i.e., warm
dry summers and cool moist winters (WILD 2004). It has
become a major pest in many areas around the world with
similar climates. Recently, several papers have examined
the worldwide spread of L. humile and predicted its poten-
tial distribution based on current and future climate es-
timates (SUAREZ & al. 2001, HARTLEY & LESTER 2003,
ROURA-PASCUAL & al. 2004, HARTLEY & al. 2006, WARD
Figs. 1 - 4: Linepithema humile. (1) head of worker from Entre Rios, Argentina (specimen ID = CASENT0106983); (2)
lateral view of the same worker; (3) dorsal view of the same worker; (4) worker tending a scale insect in California (photos
by A.L. Wild).
2007). In the present paper, we have documented more
fully the historic spread and current worldwide distribution
of L. humile, and corrected some errors in the literature.
Methods
We documented the range of L. humile using both published
and unpublished records. Antbase.org and the FORMIS
bibliography were essential resources for finding relevant
published papers. We obtained unpublished site records
from the collections of American Museum of Natural His-
tory (AMNH), Archbold Biological Station (ABS), the
Natural History Museum, London (BMNH), the California
Academy of Science (CAS), the Field Museum (FM), the
Florida State Arthropod collection (FSAC), the Los Ange-
les Museum of Natural History (LACM), the Museum of
Comparative Zoology (MCZ), the Museo Civico di Storia
Naturale "Giacomo Doria" (MSNG), the Museu de Zoolo-
gia da Universidade de São Paulo (MZSP), the Naturhis-
torisches Museum Wien (NMW), the Oxford University,
Museum of Natural History (OUNH), the Museo de Zoo-
logía, Pontifica Universidad Católica del Ecuador (QCAZ),
the Smithsonian Institute (SI), the University of Arizona
Museum (UAM), and the University of Minnesota Museum
(UMM), and from on-line databases of the Australian Nati-
onal Insect Collection, the California Academy of Science,
Fauna Europaea, the Global Diversity Information Facility,
Landcare Research, the Essig Museum, the Pacific Basin
Information Node, and the Nebraska State Insect Records
(NSIR). We received unpublished site records from E. Bod-
son (Belgium), J. Delabie (Brazil, Chile, Tunisia), R. Guillem
(Gibraltar, Morocco), G. Heller (Canary Islands, Italy, Fran-
ce, Spain), M. Lush (Spain), and P. Pellitteri (Wisconsin).
We also included our own unpublished specimen records.
If a site record listed a geographic region rather than a
"point locale," and we had no other record for this region,
we used the coordinates of the capital or largest town
within the region or, in the case of small islands and nat-
ural areas, the center of the region. Often, if one reference
had many sites less than 10 - 20 km apart (e.g., HUDDLE-
STON & FLUKER 1968), we did not plot every site. We did
not map records of L. humile on boats or intercepted in
transit by quarantine inspectors, though it is possible that we
included some quarantine records that were not labeled as
such.
Because WILD (2007) found many L. humile records
from South and Central America were misidentifications of
other Linepithema species (e.g., Linepithema dispertitum
(FOREL, 1885), Linepithema iniquum (MAYR, 1870), and
Linepithema neotropicum WILD, 2007), we excluded all
South and Central American records not confirmed by
188
Fig. 5: Worldwide distribution of Linepithema humile.
WILD (2007). In contrast, the only other Linepithema spe-
cies that WILD (2007) recorded from outside South and
Central America were a few L. iniquum records from Bel-
gium (two records), Germany (one record), Ireland (one
record), and Massachusetts (one record). We therefore map-
ped all other L. humile records outside South and Central
America assuming that they were fairly reliable.
Results
We plotted records of L. humile from > 2100 sites around
the world (Fig. 5). These records of L. humile came from
95 different geographic areas (i.e., countries, island groups,
major islands, and US states), including several for which
we found no previously published records: Tunisia, Idaho,
Nebraska, Pennsylvania, and Wisconsin (Tabs. 1 - 6).
We could not confirm any L. humile records from sev-
eral South and Central American countries with published
reports: Costa Rica, El Salvador, Guyana, Surinam, and
Venezuela. WILD (2007) found that many published rec-
ords of L. humile from South and Central America were
actually based on misidentification of other species: e.g.,
Costa Rica (PERFECTO & SNELLING 1995; all records = L.
neotropicum), Venezuela (ROURA-PASCUAL & al. 2004;
only record = L. iniquum), and El Salvador (ROURA-
PASCUAL & al. 2004; only record = L. dispertitum). We
could not find any specimens confirming published L.
humile records from Surinam and Guyana (DÜRR 1952).
We excluded unconfirmed L. humile records from other
South and Central American countries, including several
that predate our earliest confirmed records from those coun-
tries: Brazil (e.g., VON IHERING 1894), Colombia (e.g., FO-
REL 1912), Chile (e.g., NEWELL & BARBER 1913), Mex-
ico (e.g., CARPENTER 1902), and Peru (e.g., DALE 1974).
Discussion
Originally from subtropical South America, Linepithema
humile began its spread to the greater Mediterranean re-
gion in the 19th century. The earliest known specimen of
L. humile, predating even the type specimens collected in
Tab. 1: Earliest confirmed records of Linepithema humile
from South and Central America. See text for acronyms.
* = see text for earlier unconfirmed published records.
Native range
Earliest confirmed record
Argentina 1866 (MAYR 1868)
Uruguay 1885 (collector unknown; NMW): Monte-
video
Paraguay 1896 (G. Boggiani; MSNG): Puerto 14
de Mayo
Brazil 1914* (BORGMEIER 1928 as Iridomyrmex
riograndensis BORGMEIER, 1928)
Exotic range
Chile 1965* (A. München; MZSP): Temuco
Mexico 1965* (N. Krauss; BMNH): Mexico City
Colombia 1973* (W.P. Mackay; pers. coll.): Armenia
Peru 1982* (P. Majlut; MZSP): Los Condores
Ecuador 2002 (M.F. Salvador; QCAZ): Quito
Argentina in 1866 (MAYR 1868), was collected on the At-
lantic island of Madeira between 1847 and 1858 (WETTE-
RER & al. 2006). In the 19th century, Madeira was a hub
for commerce between Portugal and its colonies in South
America, and collection records suggest that L. humile
may have first spread through the greater Mediterranean re-
gion via Madeira and Portugal (WETTERER & WETTERER
2006, WETTERER & al. 2006). All of the earliest records
from continental Europe (1890 - 1896) come from Portugal
(SCHMITZ 1897, MARTINS 1907, COUTINHO 1929). Some
50 years after first being collected in Madeira, and 20 years
after being recorded in Portugal, L. humile began appear-
ing in other parts of the greater Mediterranean region (Tab.
2). By the 1920s, L. humile had been collected in two other
189
Tab. 2: Earliest known records of Linepithema humile from
the greater Mediterranean region and on Atlantic islands.
See text for acronyms. + = no previously published records.
Earliest record
+ Madeira 1858 (WETTERER & al. 2006)
+ Portugal 1890 (MARTINS 1907)
+ Italy 1902 (SILVESTRI 1922)
+ France ~ 1906 (MARCHAL 1917)
+ Canary Islands 1909 (STITZ 1916)
+ Spain 1916 (FRISQUE 1935)
+ Bosnia 1916 (FRISQUE 1935)
+ Azores 1921 (CHOPARD 1921)
+ Monaco 1921 (CHOPARD 1921)
+ Algeria 1923 (FRISQUE 1935)
+ Sicily 1926 (H. Donisthorpe, BMNH):
Palermo
+ Bermuda 1949 (BENNETT & HUGHES 1959)
+ Balearic Islands 1953 (GÓMEZ & ESPADALER 2006)
+ Morocco 1956 (WETTERER & al. 2006)
+ Greece 1967 (BERNARD 1968)
+ Corsica 1967 (BERNARD 1968)
+ Malta 1968 (BARONI URBANI 1968)
+ Sardinia 1974 (CASEVITZ-WEULERSSE 1974)
+ St Helena 2002 (WETTERER & al. 2007)
+ Bulgaria 2004 (RADCHENKO 2004)
+ Crete 2004 (RADCHENKO 2004)
+ Gibraltar 2004 (RADCHENKO 2004)
+ Tunisia 2005 (J. Delabie, pers comm.):
Hammamet
North Atlantic archipelagos (Canary Islands and Azores)
and from numerous sites in southwestern Europe (Spain,
southern France, and Italy). Later, L. humile began to turn
up in coastal North Africa and the central Mediterranean
(Tab. 2, Fig. 5). Linepithema humile arrived in Bermuda
in the 1940's, and is now the most-dominant ant species
there (WETTERER & WETTERER 2004).
Shortly after appearing in southern Europe, L. humile
began to be reported as an indoor pest in northern Europe
(Tab. 3, Fig. 5). The earliest of these records came from
Belfast, Northern Ireland, where CARPENTER (1902) report-
ed an enormous L. humile population living under the floors
and in the walls of a home. The highest latitude records
come from Sandnes, Norway (58.85° N), where GÓMEZ
& al. (2005) reported L. humile living in two apartments.
Greenhouse records of L. humile are common from many
parts of Europe. Because L. humile can live anywhere that
humans live, there is no limit to the latitude where indoor
populations of this species may be found.
Tab. 3: Earliest known records of Linepithema humile from
western, northern and central Europe.
Earliest record
Ireland (Northern) 1899 (CARPENTER 1902)
Germany 1901 (STITZ 1939)
Belgium 1911 (BONDROIT 1911)
Scotland 1912 (DONISTHORPE 1927)
Poland 1915 (PAX 1915)
England 1915 (DONISTHORPE 1916)
Ireland (Eire) 1921 (CHOPARD 1921)
Guernsey 1927 (DONISTHORPE 1927)
Czech Republic 1947 (NOVÁK 1947)
Austria 1952 (HÖLZEL 1966)
Switzerland 1980 (KUTTER 1981)
Sweden 1995 (DOUWES 1995)
Netherlands 2002 (VIERBERGEN 2003)
Norway 2004 (GÓMEZ & al. 2005)
Linepithema humile arrived in the US in the late 19th
century, where it was first noted in New Orleans (TITUS
1905). It was soon found in subtropical sites across the
Southeast US and California (Tab. 4, Fig. 5). Linepithema
humile now dominates at many urban and riparian sites in
California, and has indoor and greenhouse records scattered
across temperate parts of the US (Tab. 4, Fig. 5), e.g., in the
Desert Dome Exhibit of the Henry Doorly Zoo in Omaha,
Nebraska (2003; NSIR).
In South and Central America, L. humile has extended
its range into temperate and tropical regions (Tab. 1, Fig. 5),
though it is not known as a dominant species in any of these
areas. Many tropical records are from highland areas, e.g.,
around Mexico City (WILD 2004). Most records from ar-
eas with climates less hospitable to L. humile may come
from indoor populations.
Linepithema humile has also been reported from sub-
tropical areas of southern Africa and southern Australia with
Mediterranean-like climates (Tab. 5, Fig. 5), where it has
long been a major widespread pest (CLARK 1941, DÜRR
1952). More recently, L. humile has begun to spread across
subtropical parts of Oceania and Asia, and a few other sub-
tropical locales (Tab. 5).
In tropical Oceania, L. humile is known primarily from
Hawaii (Tab. 6, Fig. 5). COLE & al. (1992) studied the im-
pact of L. humile in the highlands of Maui, where it reaches
elevations up to 2880 m. WETTERER & al. (1998) found L.
humile were common on the dry western slope of Mauna
Kea volcano on the Big Island up to 1680 - 2020 m ele-
vation, but densities quickly dropped off in the cooler areas
above this elevation (maximum elevation 2640 m). Linepi-
thema humile also has records from other tropical locales
(e.g., Indonesia, Cameroon, and Zimbabwe), though these
may be indoor records.
190
Tab. 4: Earliest known records of Linepithema humile from
US states. See text for acronyms. + = no previously pub-
lished records.
Earliest record
+ Louisiana 1891 (TITUS 1905)
+ Mississippi 1904 (TITUS 1905)
+ California 1905 (SMITH 1936)
+ Illinois 1906 (SMITH 1936)
+ Alabama 1913 (NEWELL & BARBER 1913)
+ Texas 1914 (NEWELL 1914)
+ Florida 1914 (WHEELER 1932)
+ Arkansas 1915 (BARBER 1916)
+ Georgia 1915 (BARBER 1916)
+ North Carolina 1915 (BARBER 1916)
+ South Carolina 1915 (BARBER 1916)
+ Tennessee 1915 (BARBER 1916)
+ Arizona 1922 (collector unknown, UAM):
Douglas
+ South Dakota 1924 (H.C. Severin, MCZ): Brookings
+ Maryland 1931 (SMITH 1936)
+ Missouri 1933 (SMITH 1936)
+ Virginia 1936 (SMITH 1936)
+ Washington 1938 (R. Gregg, FM): Spokane
+ Minnesota 1941 (collector unknown, UMM):
St. Paul
+ Oregon 1942 (MALLIS 1942)
+ Nevada 1953 (LA RIVERS 1968)
+ Utah 1982 (ALLRED 1982)
+ Nebraska 1983 (A. Tosco, NSIR): Omaha
+ Oklahoma 1992 (ALBRECHT 1995)
+ Ohio 1993 (ARNETT 1993 in COOVERT 2005)
+ Pennsylvania 1993 (KING & GREEN 1994): Philadelphia
+ Michigan 1998 (GULMAHAMAD 1998)
+ New Mexico 2002 (MACKAY & MACKAY 2002)
+ Idaho 2005 (Ventana, SI): Sierra
+ Indiana 2005 (ROBINSON 2005)
+ Wisconsin 2006 (P. Pellitteri, pers. comm.):
Fond du Lac
Future spread
Linepithema humile has already spread to most subtrop-
ical lowland areas around the world with Mediterranean-
like climates, where we would expect its impact would be
Tab. 5: Earliest known records of Linepithema humile from
subtropical parts of sub-Saharan Africa, Asia, Australia,
and Oceania. See text for acronyms.
Earliest record
South Africa 1893 (LOUNSBURY 1909)
Lesotho 1908 (Wroughton, SI): Maseru
Juan Fernandez 1920 (collector unknown, LACM):
site unknown
Australia ~ 1931 (CLARK 1941)
Namibia 1982 (A.C. Marsh, BMNH):
Swakopmund
Easter Island 1987 (G. Pauley, SI): Hanga Roa
New Zealand 1990 (GREEN 1990)
Japan 1993 (SUGIYAMA 2000)
United Arab Emirates 1995 (COLLINGWOOD & al. 1997)
North Korea 2005 (RADCHENKO 2005)
Tab. 6: Earliest known records of Linepithema humile from
the Old World tropics. See text for acronyms.
Earliest record
Hawaii 1916 (FRISQUE 1935)
Indonesia 1944 (DONISTHORPE 1950)
Cameroon 1979 (D. Jackson, BMNH): Nkoemvom
Zimbabwe 1986 (FERRER 2000)
Yemen 1998 (COLLINGWOOD & VAN HARTEN 2001)
Philippines 1999 (DAFF 2001)
Malaysia 2000 (NA & LEE 2001)
Vietnam 2005 (RADCHENKO 2005)
the greatest. Within these areas, many populations are still
expanding (e.g., Santa Cruz Island, California, WETTERER
& al. 2001; Japan, OKAUE & al. 2007; New Zealand, WARD
& al. 2005). In some areas, however, populations have de-
clined. For example, on the island of Madeira, L. humile was
once a serious pest, but now it is relatively uncommon, ex-
cept in the semi-arid eastern regions (WETTERER & al. 2006).
Despite BYTINSKI-SALZ's (1952) prediction that L. hu-
mile "must be expected to penetrate the Eastern Mediterra-
nean soon," L. humile has not yet been reported east of
Crete. Linepithema humile also has not yet been reported
from regions of southern China and central Africa that have
appropriate Mediterranean-like climates (ROURA-PASCUAL
& al. 2004, HARTLEY & al. 2006). Although L. humile will
likely spread to other subtropical areas as well (ROURA-
PASCUAL & al. 2004, HARTLEY & al. 2006), it is unlikely
to dominate in more humid areas. The importance of aridity
in determining the dominance of L. humile is well illustrat-
ed on a fine grain scale in the Madeira archipelago, where
191
L. humile is common in the dry eastern parts, but relatively
rare in wetter areas (WETTERER & al. 2006). Linepithema
humile once was a significant pest across much of the hu-
mid southeastern US, but is now largely restricted to urban
areas (e.g., see BUCZKOWSKI & al. 2004).
Linepithema humile is still largely unknown from trop-
ical highland areas that have suitable climates that might
allow it to dominate. Until recently, most exotic ant species
invading tropical regions probably arrived by sea accom-
panying human commerce. These invaders had to survive
under lowland tropical conditions before spreading to other
locales. This may explain why relatively few ant species
have invaded the cooler highland areas (REIMER 1994).
WILSON & TAYLOR (1967) noted that populations of L.
humile in Hawaii were often associated with army camps
and bivouacs, and concluded that colonies probably were
being transported inadvertently with army supplies and
equipment. Nowadays, air travel allows exotic ants to stow-
away in cargo delivered almost anywhere. The latitudinal
range of L. humile may also increase globally as a result
of climate change (ROURA-PASCUAL & al. 2004).
Acknowledgements
We thank A. Wetterer and M. Wetterer for comments on this
manuscript; S. Cover for help, encouragement, and ant iden-
tification; P. Pellitteri, M. Lush, G. Heller, R. Guillem, J.
Delabie, and E. Bodson for providing unpublished records;
B. Bolton (BMNH), J. Carpenter (AMNH), P. Clausen
(UMC), S. Cover (MCZ), M. Deyrup (ABS), J. Hogan
(ONHM), G. Knight (NML), and T. Schultz (SI) for help
with their respective ant collections; W. O'Brien for GIS
help; D.P. Wojcik and S.D. Porter for compiling their valu-
able FORMIS bibliography; C. Scheid and R. Pasos of the
FAU library for processing so many interlibrary loans;
Florida Atlantic University, the National Science Founda-
tion, and the National Geographic Society for financial sup-
port.
Zusammenfassung
Die Argentinische Ameise, Linepithema humile (MAYR,
1868), mit Ursprung im subtropischen Südamerika, ist in
vielen Teilen der Erde ein bedeutsamer Lästling. Um die
weltweite Verbreitung und das Potenzial für weitere Aus-
breitung zu bewerten, haben wir Nachweise von L. humile
von > 2100 Fundorten gesammelt. Da mehrere süd- und
mittelamerikanische Linepithema-Arten oft fälschlicher-
weise als L. humile bestimmt wurden, haben wir alle un-
bestätigten Nachweise aus Süd- und Mittelamerika ausge-
schlossen. Wir dokumentierten die frühesten bekannten
Nachweise von L. humile für 95 geographische Gebiete
(Länder, Inselgruppen, große Inseln und US-Bundesstaa-
ten), einschließlich einiger, für die wir keine bisher ver-
öffentlichten Nachweise gefunden haben. Für einige süd-
und mittelamerikanische Länder konnten wir keinen der
veröffentlichten Berichte von Vorkommen von L. humile
bestätigen.
Die meisten Nachweise von L. humile stammen aus den
Subtropen, insbesondere aus Regionen mit mediterranem
Klima (warm-trockene Sommer und kühl-feuchte Winter),
einschließlich dem ursprüngliche Verbreitungsgebiet in Süd-
amerika und exotische Populationen in Kalifornien, dem
Mittelmeerbereich, dem südlichen Afrika, sowie in Aus-
tralien, Neuseeland und Japan. In humideren subtropischen
Gebieten, wie dem Südosten der Vereinigten Staaten, domi-
niert L. humile nur selten außerhalb urbaner Bereiche. In
tropischen Gebieten dominiert L. humile nur in Höhenla-
gen, mit Hawaii als prominentem Beispiel. In temperaten
Gebieten ist L. humile fast ausschließlich ein Lästling in
Gebäuden.
Linepithema humile hat bereits die meisten subtropi-
schen Gebiete mit Tieflage und mediterranem Klima er-
reicht, ist aber bisher für die meisten tropischen Gebiete mit
Höhenlage und geeignetem Klima nicht nachgewiesen. In
der Vergangenheit hat L. humile tropische Regionen wahr-
scheinlich am Seeweg in Folge menschlicher Handelsak-
tivitäten erreicht und musste die Tieflandbedingungen der
Küste überleben, um sich anschließend in kühlere Höhen-
lagen ausbreiten zu können. Heute ermöglicht die Luftfahrt
L. humile, als blinde Passagiere in Frachtgut an nahezu jeden
Punkt der Erde zu gelangen. Deshalb ist eine fortschreiten-
de Ausbreitung des Lästlings für die Zukunft zu erwarten.
References
ALBRECHT, M. 1995: New species distributions of ants in Okla-
homa, including a South American invader. – Proceedings of
the Oklahoma Academy of Science 75: 21-24.
ALLEN, C.R., EPPERSON, D.M. & GARMESTANI, A.S. 2004: Red
imported fire ant impacts on wildlife: a decade of research. –
American Midland Naturalist 152: 88-103.
ALLRED, D.M. 1982: Ants of Utah. – Great Basin Naturalist 42:
415-511.
BARBER, E.R. 1916: The Argentine ant: distribution and control
in the United States. – USDA Bulletin 377: 1-23.
BARONI URBANI, C. 1968: Studi sulla mirmecofauna d'Italia. IV.
La fauna mirmecologica delle isole Maltesi ed il suo signifi-
cato ecologico e biogeografico. – Annali del Museo Civico di
Storia Naturale 77: 408-559.
BENNETT, F.D. & HUGHES, I.W. 1959: Biological control of in-
sect pests in Bermuda. – Bulletin of Entomological Research
50: 423-436.
BERNARD, F. 1968: Faune de l'Europe et du Bassin Méditerra-
néen. 3. Les fourmis (Hymenoptera Formicidae) d'Europe oc-
cidentale et septentrionale. – Masson, Paris, 411 pp.
BONDROIT, J. 1911: Fourmis exotiques importées au jardin bota-
nique de Bruxelles. – Annales de la Société Entomologique de
Belgique 55: 14.
BORGMEIER, T. 1928: Algumas formigas do Museo Paulista. –
Boletim Biológico, Laboratório de Parasitologia da Faculdade
de Medicina de São Paulo 12: 55-70.
BUCZKOWSKI, G., VARGO, E.L. & SILVERMAN, J. 2004: The dimi-
nutive supercolony: the Argentine ants of the southeastern Un-
ited States. – Molecular Ecology 13: 2235-2242.
BYTINSKI-SALZ, H. 1952: The zoogeography of the ants in the
Near East. – Istanbul Universitesi Fen Fakultesi Mecmuasi,
Seri B 18: 67-74.
CARPENTER, G.H. 1902: Household insects. A tropical black ant.
Iridomyrmex humilis, MAYR. – Economic Proceedings of the
Royal Dublin Society 1: 155-157.
CASEVITZ-WEULERSSE, J. 1974: Premières données pour une étude
écologique des fourmis de la Corse. – Bulletin d'Ecologie 5:
55-70.
CHOPARD, L. 1921: La fourmi d'Argentine Iridomyrmex humilis
var. arrogans SANTSCHI dans le midi de la France. – Annales
des Épiphyties 7: 237-265.
192
CLARK, J. 1941: Notes on the Argentine ant and other exotic ants
introduced into Australia. – Memoirs of the National Museum
of Victoria 12: 59-70.
COLE, F.R., MEDEIROS, A.C., LOOPE, L.L. & ZUEHLKE, W.W.
1992: Effects of the Argentine ant on arthropod fauna of
Hawaiian high-elevation shrubland. – Ecology 73: 1313-1322.
COLLINGWOOD, C.A., TIGAR, B.J. & AGOSTI, D. 1997: Introduced
ants in the United Arab Emirates. – Journal of Arid Environ-
ments 37: 505-512.
COLLINGWOOD, C.A. & VAN HARTEN, A. 2001: The ants (Hym.,
Formicidae) of Niue, south west Pacific. – Entomologists'
Monthly Magazine 137: 139-144.
COOVERT, G.A. 2005: The ants of Ohio (Hymenoptera: Formici-
dae). – Bulletin of the Ohio Biological Survey 15 (2): 1-202.
COUTINHO, M.P. 1929: A "formiga argentina" "Iridomyrmex hu-
milis", MAYR "var. arrogans", SANTSCHI. – Boletim do Minis-
tério da Agricultura Ano 11 (13-18): 95-116.
DAFF 2001: Import risk analysis (IRA) for the importation of
fresh pineapple fruit. – Australian Government Department of
Agriculture, Fisheries & Forestry, Canberra, 270 pp.
DALE, W.E. 1974: Hormigas en viviendas y jardines de Lima
Metropolitana: Iridomyrmex humilis (MAYR) y Monomorium
pharaonis (L). – Revista Peruana de Entomología 17: 126-127.
DONISTHORPE, H. 1916: Myrmecophilous notes for 1915. – Ento-
mologist's Record and Journal of Variation 28: 1-4.
DONISTHORPE, H. 1927: The ants (Formicidae), and some myr-
mecophiles, of Sicily. – Entomologist's Record and Journal
of Variation 39: 6-9.
DONISTHORPE, H. 1950: An eighth installment of the Ross Col-
lection of ants from New Guinea. – Annals and Magazine of
Natural History (12) 3: 338-341.
DOUWES, P. 1995: Sveriges myror. – Entomologisk Tidskrift 116:
83-99.
DÜRR, H.J.R. 1952: The Argentine ant Iridomyrmex humilis
(MAYR). – Farming in South Africa 54: 381-384, 390.
FERRER, J. 2000: Linepithema humile MAYR 1868 fourmi argen-
tine, présente dans le Midi de France, découverte au Zim-
babwe (Hymenoptera, Formicidae). – Nouvelle Revue d'Ento-
mologie 17: 289-290.
FOREL, A. 1912: Formicides Néotropiques. Part V. 4me sous-
famille Dolichoderinae FOREL. – Memoires de la Société En-
tomologique de Belgique 20: 33-58.
FRISQUE, K. 1935: La Fourmi d'Argentine Iridomyrmex humilis
MAYR dans les serres en Belgique. – Annales de la Société
Entomologique de Belgique 75: 148-153.
GÓMEZ, C., ROURA-PASCUAL, N. & BIRKEMOE, T. 2005: Argen-
tine ants Linepithema humile (MAYR, 1868) infesting Norwe-
gian flats. – Norwegian Journal of Entomology 52: 65-66.
GÓMEZ, K. & ESPADALER, X. 2006: Exotic ants (Hymenoptera:
Formicidae) in the Balearic Islands. – Myrmecologische Nach-
richten 8: 225-233.
GREEN, O.R. 1990: Entomologist sets new record at Mt. Smart:
Iridomyrmex humilis established in New Zealand. – Weta
13(1): 14-16.
GULMAHAMAD, H. 1998: California's blight. – PCT Online 37
(199), <http://www.pctonline.com/articles/article.asp?ID=
199&IssueID=37>, retrieved on 20 April 2009.
HARTLEY, S., HARRIS, R. & LESTER, P.J. 2006: Quantifying un-
certainty in the potential distribution of an invasive species:
climate and the Argentine ant. – Ecology Letters 9: 1068-1079.
HARTLEY, S. & LESTER, P.J. 2003: Temperature-dependent de-
velopment of the argentine ant, Linepithema humile (MAYR)
(Hymenoptera: Formicidae): a degree-day model with implica-
tions for range limits in New Zealand. – New Zealand Ento-
mologist 26: 91-100.
HÖLZEL, E. 1966: Hymenoptera-Heterogyna: Formicidae. – Cata-
logus Faunae Austriae 16: 1-12.
HUDDLESTON, E.W. & FLUKER, S.S. 1968: Distribution of ant
species of Hawaii. – Proceedings of the Hawaiian Entomo-
logical Society 20: 45-69.
KING, T.G. & GREEN, S.A. 1994: Ants (Hymenoptera: Formici-
dae) collected in Philadelphia, Pennsylvania, USA. – <http://
biodiversity.georgetown.edu/searchfiles/infosearch.cfm?view
=all&IDNumber=2819>, retrieved on 20 April 2009.
KUTTER, H. 1981: Iridomyrmex humilis MAYR (Hym., Formici-
dae), Gattung und Art neu für die Schweiz. – Mitteilungen der
Schweizerischen Entomologischen Gesellschaft 54: 171-172.
LA RIVERS, I. 1968: A first listing of the ants of Nevada (Hyme-
noptera, Formicidae). – Biological Society of Nevada Occa-
sional Papers 17: 1-12.
LOUNSBURY, C.P. 1909: Appendix IV. Report of the government
entomologist for the year 1908. – Cape of Good Hope, Report
of the Department of Agriculture 1908: 55-70.
MACKAY, W. & MACKAY, E. 2002: The ants of New Mexico. –
Edwin Mellen Press, Lewiston, 408 pp.
MALLIS, A. 1942: Half a century with the successful Argentine
ant. – Scientific Monthly 55: 526-545.
MARCHAL, P. 1917: La fourmi d'Argentine (Iridomyrmex humilis
MAYR). – Bulletin de la Societé d' Etude et de Vulgarisation de
Zoologie et d'Agriculture de Bordeaux 16: 23-26.
MARTINS, M.N. 1907: Une fourmi terrible envahissant l'Europe
(Iridomyrmex humilis MAYR). – Brotéria, Series Zoología 6:
101-102.
MAYR, G. 1868: Formicidae novae Americanae collectae a Prof.
P. de Strobel. – Annuario della Societa dei Naturalisti Modena
3: 161-178.
NA, J.P.S. & LEE, C.Y. 2001: Identification key to common ur-
ban pest ants in Malaysia. – Tropical Biomedicine 18: 1-17.
NEWELL, W. 1914: A natural enemy of the Argentine ant. – Jour-
nal of Economic Entomology 7: 147.
NEWELL, W. & BARBER, T.C. 1913: The Argentine ant. – Bulletin
of the USDA Bureau of Entomology 122: 1-98.
NOVÁK, V. 1947: Exotictí mravenci ve sklenících Prazské bota-
nické zahrady. – Casopis Ceské Spolecnosti Entomologické
44: 144-146.
OKAUE, M., YAMAMOTO, K., TOUYAMA, Y., KAMEYAMA, T., TERA-
YAMA, M., SUGIYAMA, T., MURAKAMI, K. & ITO, F. 2007: Dis-
tribution of the Argentine ant, Linepithema humile, along the
Seto Inland Sea, western Japan: Result of surveys in 2003-
2005. – Entomological Science 10: 337-342.
PAX, F. 1915: Beobachtungen über das Auftreten der "argentini-
schen Ameisen", Iridomyrmex humilis MAYR, in Schlesien. –
Schlesische Monatsschrift des Obst-, Gemüse- und Garten-
baus, Breslau 4(3): 33.
PERFECTO, I. & SNELLING, R.R. 1995: Biodiversity and the trans-
formation of a tropical agroecosystem: ants in coffee planta-
tions. – Ecological Applications 5: 1084-1097.
RADCHENKO, A. 2004: Formicidae. – Fauna Europaea version 1.1,
<http://www.faunaeur.org>, retrieved on 20 April 2009.
RADCHENKO, A. 2005: Monographic revision of the ants (Hyme-
noptera: Formicidae) of North Korea. – Annales Zoologici 55:
127-221.
REIMER, N.J. 1994: Distribution and impact of alien ants in vul-
nerable Hawaiian ecosystems. In: WILLIAMS, D.F. (Ed.): Ex-
otic ants: biology, impact, and control of introduced species.
– Westview Press, Boulder, CO, pp. 11-22.
193
194
ROBINSON, W.H. 2005: Handbook of urban insects and arach-
nids. – Cambridge University Press, Cambridge, MA, 480 pp.
ROURA-PASCUAL, N., SUAREZ, A.V., GÓMEZ, C., PONS, P., TOU-
YAMA, Y., WILD, A.L. & PETERSON, A.T. 2004: Geographic pot-
ential of Argentine ants (Linepithema humile MAYR) in the
face of global climate change. – Proceedings of the Royal So-
ciety of London Series B 271: 2527-2534.
SCHMITZ, E. 1897: As formigas da Madeira. – Annaes de Scien-
cias Naturaes 4: 77.
SILVESTRI, F. 1922: La Formica Argentina. – R. Laboratorio di
Entomologia Agraria Portici 1: 1-7.
SMITH, M.R. 1936: Distribution of the Argentine ant in the Unit-
ed States and suggestions for its control or eradication. – United
States Department of Agriculture Circular 387: 1-39.
STITZ, H. 1916: Formiciden. – Ergebnisse der Zweiten Deutschen
Zentral-Afrika Expedition 1: 369-405.
STITZ, H. 1939: Hautflügler oder Hymenoptera. 1 Ameisen oder
Formicidae. – Die Tierwelt Deutschlands und der angrenzenden
Meeresteile, nach ihren Merkmalen und nach ihrer Lebens-
weise 37: 1-428.
SUAREZ, A.V., HOLWAY, D.A. & CASE, T.J. 2001: Patterns of
spread in biological invasions dominated by long-distance
jump dispersal: insights from Argentine ants. – Proceedings
of the National Academy of Sciences of the United States of
America 98: 1095-1100.
SUAREZ, A.V., YEH, P. & CASE, T.J. 2005: Impacts of Argentine
ants on avian nesting success. – Insectes Sociaux 52: 378-382.
SUGIYAMA, T. 2000: Invasion of Argentine Ant, Linepithema hu-
mile, into Hiroshima Prefecture, Japan. – Japanese Journal of
Applied Entomology and Zoology 44: 127-129.
TALBOT, M. 1934: Distribution of ant species in the Chicago re-
gion with reference to ecological factors and physiological tol-
eration. – Ecology 15: 416-439.
TITUS, E.S.G. 1905: Report on the "New Orleans" ant (Iridomyr-
mex humilis MAYR). – U.S. Bureau of Entomology Bulletin
52: 79-84.
VEGA, S.J. & RUST, M.K. 2001: The Argentine ant – a signifi-
cant invasive species in agricultural, urban and natural envir-
onments. – Sociobiology 37: 3-25.
VIERBERGEN, B. 2003: Technomyrmex albipes en andere exoten
in Nederland. – Forum Formicedarum 4(2): 4-7.
VON IHERING, H. 1894: Die Ameisen von Rio Grande do Sul. –
Berliner Entomologische Zeitschrift 39: 321-446.
WARD, D.F. 2007: Modeling the potential geographic distribution
of invasive ant species in New Zealand. – Biological Inva-
sions 9: 723-735.
WARD, D.F., HARRIS, R.J. & STANLEY, M.C. 2005: Human me-
diated range expansion of Argentine ants Linepithema humile
(Hymenoptera: Formicidae) in New Zealand. – Sociobiology
45: 401-407.
WETTERER, J.K. 2005: Worldwide distribution and potential spread
of the long-legged ant, Anoplolepis gracilipes. – Sociobiology
45: 77-97.
WETTERER, J.K. 2007: Biology and impact of Pacific islands in-
vasive species: Pheidole megacephala (Hymenoptera: Formi-
cidae). – Pacific Science 61: 437-456.
WETTERER, J.K., BANKO, P.C., LANIAWE, L.P., SLOTTERBACK,
J.W. & BRENNER, G.J. 1998: Non-indigenous ants at high ele-
vations on Mauna Kea, Hawaii. – Pacific Science 52: 228-236.
WETTERER, J.K., ESPADALER, X., ASHMOLE, P., CUTLER, C. &
ENDEMAN, J. 2007: Ants (Hymenoptera: Formicidae) of the
South Atlantic islands of Ascension Island, St Helena, and
Tristan da Cunha. – Myrmecological News 10: 29-37.
WETTERER, J.K., ESPADALER, X., WETTERER, A.L., AGUIN-POMBO,
D. & FRANQUINHO-AGUIAR, A.M. 2006: Long-term impact of
exotic ants on the native ants of Madeira. – Ecological Ento-
mology 31: 358-368.
WETTERER, J.K. & PORTER, S.D. 2003: The little fire ant, Wasman-
nia auropunctata: distribution, impact, and control. – Socio-
biology 42: 1-41.
WETTERER, J.K. & WETTERER, A.L. 2004: Ants (Hymenoptera:
Formicidae) of Bermuda. – Florida Entomologist 87: 212-221.
WETTERER, J.K. & WETTERER, A.L. 2006: A disjunct Argentine
ant metacolony in Macaronesia and southwestern Europe. –
Biological Invasions 8: 1123-1129.
WETTERER, J.K., WETTERER, A.L. & HEBARD, E. 2001: Impact of
the Argentine ant, Linepithema humile, on the native ants of
Santa Cruz Island, California. – Sociobiology 38: 709-721.
WHEELER, W.M. 1932: A list of the ants of Florida with de-
scriptions of new forms. – Journal of the New York Entomo-
logical Society 40: 1-17.
WILD, A. 2004: Taxonomy and distribution of the Argentine ant,
Linepithema humile (Hymenoptera: Formicidae). – Annals of
the Entomological Society of America 97: 1204-1215.
WILD, A. 2007: Taxonomic revision of the ant genus Linepithema
(Hymenoptera: Formicidae). – University of California Pub-
lications in Entomology 126: 1-151.
WILSON, E.O. & TAYLOR, R.W. 1967: Ants of Polynesia. – Paci-
fic Insects Monographs 14: 1-109.
  • Article
    Full-text available
    1.Once established in new areas, introduced species may exhibit changes in their biology due to phenotypic plasticity, novel selection pressures and genetic drift. Moreover, the introduction process itself has been hypothesised to act as a selective filter for traits that promote invasiveness. 2.We tested the hypothesis that behaviours thought to promote invasiveness – such as increased foraging activity and aggression – are selected for during invasion by comparing traits among native and introduced populations of the widespread Argentine ant (Linepithema humile). 3.We studied Argentine ant populations in the native range in Argentina, and in three invaded regions along an introduction pathway: California, Australia and New Zealand. In each region, we set up 32 experimental colonies to measure foraging activity, and interspecific aggression in a subset of the study regions. These colonies were subject to experimental manipulation of carbohydrate availability and octopamine, a biogenic amine known to modulate behaviour in insects, to measure variation in behavioural plasticity. 4.We found variation in foraging activity among populations, but this variation was not consistent with selection on behaviour in relation to the invasion process. We found that colonies with limited access to carbohydrates exhibited unchanged exploratory behaviour, but higher exploitation activity and lower aggression. Colonies given octopamine consistently increased foraging behaviour (both exploration and exploitation), as well as aggression when sugar‐deprived. There was no difference in the degree of behavioural response to our experimental treatments along the introduction pathway. 5.We did not find support for selection of behavioural traits associated with invasiveness along the Argentine ant's introduction pathway, or clear evidence for an association between the introduction process and variation in behavioural plasticity. These results indicate that mechanisms promote behavioural variation in a similar fashion both in native and introduced ranges. Our results challenge the assumption that introduced populations always perform better in key behavioural traits hypothesised to be associated with invasion success. This article is protected by copyright. All rights reserved.
  • Article
    Full-text available
    The extreme diversity of dispersal strategies in ants is unique among terrestrial animals. The nature of ant colonies as social, perennial, and sessile superorganisms is the basis for understanding this diversity, together with the inclusive fitness framework for social evolution. We review ant dispersal strategies, with the aim of identifying future research directions on ant dispersal and its evolution. We list ultimate and proximate determinants of dispersal traits and the ecological and evolutionary consequences of dispersal for population structures and dynamics, as well as species communities. We outline the eco-evolutionary feedbacks between the multitude of traits affecting dispersal evolution and the likely evolutionary routes and ecological drivers in transitions among the diverse ant dispersal strategies. We conclude by presenting a research framework to fill the gaps in current knowledge, including comparative studies of colony life histories and population structures and theoretical models of the eco-evolutionary dynamics affecting dispersal, in an inclusive-fitness framework.
  • Article
    Full-text available
    The little fire ant Wasmannia auropunctata, native to the Neotropics, has become a serious pest worldwide over the past 100 years. It was originally distributed from Mexico to northern Argentina and new evidence suggests a recent southern range expansion during the last 60 years reaching central Argentina. This supercolonial ant species has a polymorphic reproductive system. Some populations, mostly found in undisturbed natural environments, are characterised by a classical sexual haplodiploid reproductive system. In other populations, which mainly occur in human-modified habitats, diploid queens and haploid males are produced clonally while workers are produced sexually. Here we studied the association between the recent southern range expansion of W. auropunctata in relation to human activity and clonality. We carried out an extensive survey within the southern limit of the species’ native distribution and characterised the type of habitat where populations were found. Moreover, we genetically determined the type of reproductive system in 35 populations by genotyping at 12 microsatellite loci a total of 191 reproductive individuals (i.e. queens and/or males). Clonality was the most common reproductive system, occurring in 31 out of 35 populations analysed. All the populations found in the recently colonised area in central Argentina were clonal and established in human-modified habitats, suggesting that clonality together with human activity might have facilitated the southwards expansion of W. auropunctata.
  • Article
    The monitoring of introduced species is becoming more important as global trade intensifies. Although ants make up a larger proportion of species on the list of the most invasive species in the world compared with other groups, little is known about the occurrence of those introduced in France, especially inside heated buildings. Here we review the literature available for mainland France and Belgium and report the results of a survey conducted with the help of tropical building managers between 2014 and 2016. We report for the first time in France the presence of Technomyrmex vitiensis and Plagiolepis alluaudi in multiple greenhouses. Technomyrmex difficilis was also found in one greenhouse for the first time in Europe. The diversity of introduced ants in greenhouses is very low, and these buildings are most often dominated by one or two species. We compared the most recent data and those collected throughout the twentieth century and showed that ant communities have changed substantially. Greenhouses could be responsible for the introduction of invasive species because they regularly import exotic plants, but we found no evidence that the three species of invasive ants present outdoors in France were introduced from greenhouses, where they rarely occur. We also report that introduced ants are pests in greenhouses because they disperse scale insects and kill biological control agents. The suppression of these ants could ease the maintenance of plants inside greenhouses.
  • Article
    The Argentine ant (Linepithema humile) is a highly invasive pest, yet very little is known about its viruses. We analysed individual RNA-sequencing data from 48 Argentine ant queens to identify and characterisze their viruses. We discovered eight complete RNA virus genomes - all from different virus families - and one putative partial entomopoxvirus genome. Seven of the nine virus sequences were found from ant samples spanning 7 years, suggesting that these viruses may cause long-term infections within the super-colony. Although all nine viruses successfully infect Argentine ants, they have very different characteristics, such as genome organization, prevalence, loads, activation frequencies and rates of evolution. The eight RNA viruses constituted in total 23 different virus combinations which, based on statistical analysis, were non-random, suggesting that virus compatibility is a factor in infections. We also searched for virus sequences from New Zealand and Californian Argentine ant RNA-sequencing data and discovered that many of the viruses are found on different continents, yet some viruses are prevalent only in certain colonies. The viral loads described here most probably present a normal asymptomatic level of infection; nevertheless, detailed knowledge of Argentine ant viruses may enable the design of viral biocontrol methods against this pest.
  • Article
    Full-text available
    Three species of Agromyzidae were identified at three municipalities in northern Sinaloa, Mexico. Photographs of adults, lateral and ventral aedeagus, and ejaculatory pump, as well as characteristic damage by the agromyzids on host plants were presented. Species identified were: 1. Liriomyza sativae Blanchard 1938 associated with Calendula sp., Carthamus tinctorius L., Helianthus annuus L., Lactuca sativa L., Parthenium sp., Tagetes erecta L., and Taraxacum officinale L., 2. Melanagromyza minima (Malloch 1913) associated with Wedelia sp., and 3. Melanagromyza splendida Frick 1953 boring stems of Carthamus tinctorius L. © 2018 Southwestern Entomological Society. All Rights Reserved.
  • Article
    Full-text available
    The inquiline oak gall wasp fauna emerged from agamic galls of Andricus quercuslaurinus Melika and Pujade-Villar, 2009, a dangerous pest for Quercus affinis Scheidw. and Q. laurina Humb. et Bonpl. forests in Mexico, was studied for the first time. Three species in the genus Synergus Hartig, 1840 (Synergini) were obtained from these galls: Synergus davisi (Beutenmüller, 1907), previously known only from the United States of America; Synergus estradae Pujade-Villar and Lobato-Vila, 2016, described from the state of Morelos (Mexico); and Synergus pseudofilicornis Lobato-Vila and Pujade-Villar n. sp., so far determined as Synergus filicornis Cameron, 1883 (= Synergus furnessana Weld, 1913) and here considered as a new species. Synergus pseudofilicornis n. sp. is described and illustrated. A redescription and photographs of S. davisi, as well as new distributions and host associations of S. davisi and S. estradae, are given. The value of the inquilines as biological control agents for A. quercuslaurinus is discussed, and a preliminary list of parasitoids obtained from the galls is presented.
  • Article
    Full-text available
    Various organisms emit malodorous secretions against competitors, and the potential use of these secretions in pest management should be investigated. For example, some ant species feed on similar resources as dung beetles, which might have led to counter chemical defences in dung beetles. We tested whether pygidial secretions of the dung beetle Canthon smaragdulus (Fabricius) (Coleoptera: Scarabaeidae, Scarabaeinae) alter the locomotor behaviour of the exotic urban pest ant Tapinoma melanocephalum (Fabricius) (Hymenoptera: Formicidae), specifically whether these secretions repel those ants. We also tested whether the disturbance in the locomotor behaviour of T. melanocephalum increases with the amount of pygidial secretion. We found that individual T. melanocephalum displayed changes in their locomotor behaviour when exposed to pygidial secretions of coupled dung beetles, single males, and single females. Additionally, the pygidial secretions from male and female dung beetles could repel ants. The change in the locomotor behaviour of T. melanocephalum increased with the amount of pygidial secretion. Our results suggest that the pygidial secretions of dung beetles have potential as a biological repellent of T. melanocephalum. Hence, pygidial secretions from dung beetles may be used in the future for the development of urban pest management strategies.
  • Article
    Full-text available
    The myrmecofauna has been little studied in some regions of Mexico, so state inventories continue to increase. In the northeastern region of the state of Oaxaca, the collection of ants (Hymenoptera: Formicidae) was performed directly by hand and using traps in sugarcane crops (Saccharum officinarum L.) to contribute to the inventory of Formicidae and its agricultural importance. We identified thirteen species of ants, of which five were not documented in Oaxaca. The new records add agroecological value to the known species in Oaxaca since some ants act as direct and indirect pests while others play the role of natural enemies of certain pests. Although some of the species reported in this study are common in terms of abundance in cane crops, they were not reported or identified in these agroecosystems. The presence of non-native species, which inhabit the sugar cane agroecosystems and interact positively or negatively with other arthropods associated with these crops highlights the need for knowledge of the myrmecofauna of the state of Oaxaca and, in particular, in sugarcane crops.
  • Article
    The Argentine ant, Linepithema humile (Mayr), is one of the most important invasive ant species in agricultural, urban and natural environments of Mediterranean climates worldwide. The following review is intended to summarize the important literature regarding the systematics, biology and control of this species. Special emphasis has been given to those abiotic and biotic factors that might be important in preventing the spread and impact of this tramp species.
  • Article
    Full-text available
    For more than 50 years, two exotic ant species, Linepithema humile (Mayr) and Pheidole megacephala (F.), have been battling for ecological supremacy in Bermuda. Here we summarize known ant records from Bermuda, provide an update on the conflict between the dominant ant species, and evaluate the possible impact of the dominant species on the other ants in Bermuda. We examined ant specimens from Bermuda representing 20 species: Brachymyrmex heeri Forel, B. obscurior Forel, Camponotus pennsylvanicus (De Geer), Cardiocondyla emeryi Forel, C. obscurior Wheeler, Crematogaster sp., Hypoponera opaciceps (Mayr), H. punctatissima (Roger), L. humile, Monomorium monomorium Bolton, Odontomachus ruginodis Smith, Paratrechina longicornis (Latreille), P. vividula-(Nylander), P. megacephala, Plagiolepis alluaudi Forel, Solenopsis (Diplorhoptrum) sp., Tetramorium caldarium Roger, T. simillimum (Smith), Wasmannia auropunctata (Roger), and an undetermined Dacetini. Records for all but three (H. punctatissima, P. vividula, W. auropunctata) include specimens from 1987 or later. We found no specimens to confirm records of several other ant species, including Monomorium pharaonis (L.) and Tetramorium caespitum (L.). Currently, L. humile dominates most of Bermuda, while P. megacephala appear to be at its lowest population levels recorded. Though inconspicuous, B. obscurior is common and coexists with both dominant species. Paratrechina longicornis has conspicuous populations in two urban areas. Three other ant species are well established, but inconspicuous due to small size (B. heeri, Solenopsis sp.) or subterranean habits (H. opaciceps). All other ant species appear to be rare, including at least one, O. ruginodis, which was apparently more common in the past.
  • Article
    Studies of biological diversity have focused mainly on undisturbed ecosystems, effectively neglecting potential losses due to changes in areas already altered by human intervention. In this study we test the hypothesis that measures of biological diversity change significantly with changes in agricultural practices. In particular, we examine differences in measures of ant species diversity correlated with changes in vegetational complexity associated with the modernization of Costa Rica's coffee agroecosystem. We examine patterns of within-habitat $(\alpha)$ and between-habitat $(\beta)$ diversity in the ant community. Ants were sampled in 16 coffee farms falling on a gradient of vegetational and structural complexity. Percentage of shade created by the canopy was used as an index of vegetational complexity. As a partial indicator of the food resource base, arthropods were sampled using pitfall traps. The diversity $(S, H'$, and $E)$ of ground-foraging ants decreased significantly with the reduction of vegetational diversity. However, no significant changes were recorded for the diversity of the ants on the surface of coffee bushes. Similarity indices $(I)$ showed a high degree of similarity among ant communities in coffee monocultures but a low degree of similarity among farms with high vegetational diversity. We discuss several possible mechanisms leading to reduced ant diversity.
  • Article
    Full-text available
    The long-legged ant, Anoplolepis gracilipes (formerly Anoplolepis longipes) has been long recognized for its impact on other invertebrates. In the past few years, however, A. gracilipes has been brought to world attention due to its deadly attacks on nesting birds in the Seychelles and on the endemic crabs of Christmas Island. To evaluate the distribution and potential spread of A. gracilipes, I compiled and mapped specimen records from more than 700 sites worldwide. In tropical Asia and tropical islands of the Indian and Pacific Oceans, A. gracilipes occurs throughout the moist lowlands, but is not commonly found in arid regions and sites above 1200 m elevation. In tropical Africa, it is known only from Dar es Salaam and nearby Zanzibar. In tropical Australia, A. gracilipes has been recorded primarily from moist monsoon rainforests along perennial springs and streams in the northern region and in a few towns on the north and east coasts. In the Neotropics, there are records of A. gracilipes from western Mexico. In subtropical Asia, A. gracilipes ranges up to 26-27°N in northern India, southern China, and southern islands of Japan. I found only six records from latitudes >27°, two from exterminated urban populations (Auckland, New Zealand; Brisbane, Australia) and three from probably temporary populations (Valparaíso, Chile; Durban, South Africa; Zayul, Tibet). The sixth population, on Amami-Oshima Island, Japan, may or may not be temporary. Anoplolepis gracilipes is not yet known from many moist lowland tropical areas where it would probably thrive, including west-central Africa and much of the Neotropics. Populations in western Mexico are prevented from expanding eastward by a central mountain range, but may be able to spread south, around the mountains, to the Caribbean, Central America, and South America. Records from arid Baja California, Mexico indicate that A. gracilipes can invade and persist in areas with arid climates, perhaps due to moderating effects of irrigation.
  • Article
    Full-text available
    We examined the impact of the non-indigenous Argentine ant, Linepithema humile (Mayr), on the native ants of Santa Cruz Island (SCI), the largest of the California Channel Islands. Linepithema humile, a South American native, was first found on SCI in 1996 and now occupies two areas comprising less than 1% of the island. We surveyed ants using four methods: visual surveys, bait stations, tree surveys, and soil/litter samples. We found a total of 23 ant species, including two species not native to SCI: Cardiocondyla ectopia Snelling and Linepithema humile. Numerous native ants occurred at sites uninfested by L. humile and co-occurred with L. humile at the outer boundaries of L. humile-infested territory, but at sites more than 10m within L. humile-infested territory, all but two of these species disappeared, probably due to exclusion by L. humile. Only two tiny ant species, Solenopsis molesta Say and Monomorium ergatogyna Wheeler, were found to coexist deep within the L. humile-occupied areas.
  • Article
    Full-text available
    The Argentine ant, Linepithema humile, is an invasive species with the potential to cause significant economic and ecological damage in New Zealand. Using published information on rates of development, we induced parameters for a cumulative degree-day model for each life-stage of the Argentine ant.A summary model suggested that complete development, from egg to worker, requires approximately 445 degree-days above a threshold of 15.9°C. Meteorological records of air and soil temperatures indicated a number of sites in New Zealand that fulfil this minimum temperature requirement on an annual basis. Maps based on soil temperature data indicated suitable conditions as far south as Central Otago, while air temperature data predicted a more limited northerly distribution in Northland and Hawkes Bay. Additional factors, such as microclimatic variation, thermoregulatory behaviour, biotic interactions and dispersal opportunities will also be important in determining the precise range limits of the Argentine ant in New Zealand.
  • Article
    Full-text available
    The isolated Mid-Atlantic Ridge islands of Ascension Island (8° S), St Helena (16° S), and Tristan da Cunha (37° S) are 1700 - 2800 km from Africa, the nearest continent. We compiled published, unpublished, and new records of ants from these islands and evaluated the probable origin of each species. We examined specimens representing 20 different ant species: ten from Ascension, 16 from St Helena, and one from Tristan da Cunha. These included three new records from Ascension (Pheidole teneriffana FOREL, 1893, Solenopsis sp. 1, Strumigenys emmae (EMERY, 1890)), five new records from St Helena (Hypoponera sp. 1, Linepithema humile (MAYR, 1868), Monomorium latinode MAYR, 1872, Monomorium cf. sechellense, Pheidole teneriffana), and the first identifica- tion of the only ant species known from Tristan da Cunha (Hypoponera eduardi (FOREL, 1894)). All confirmed island records, except Camponotus fabricator (F. SMITH, 1858) and Hypoponera punctatissima (ROGER, 1859) on St Helena, included specimens from 1995 or later. We could not confirm two additional published ant species records from As- cension (Cataglyphis sp., Tapinoma sp.) and one from St Helena (Camponotus castaneus (LATREILLE, 1802)). Most, if not all, of the 20 ant species we documented on South Atlantic islands, including C. fabricator, a putative St Helena endemic, may be exotic species that arrived accompanying humans. However, it is possible that some ants were present before human arrival. One candidate for native status is Cardiocondyla mauritanica FOREL, 1890, a widespread tramp species originally from Africa, found on Ascension in many uninhabited areas.