ArticlePDF Available

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


Abstract and Figures

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.
Content may be subject to copyright.
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
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:
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:;
Dr. Núria Roura-Pascual, Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Pri-
vate Bag X1, Matieland 7602, South Africa. E-mail:
Prof. Dr. Xavier Espadaler, 2. Ecology Unit, Universidad Autónoma de Barcelona, E-08193 Bellaterra, Spain. E-mail:
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.
We documented the range of L. humile using both published
and unpublished records. 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
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
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.
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).
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-
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
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):
+ 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.):
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.
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):
+ 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):
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
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).
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-
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
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
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.
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.
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:
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:
CHOPARD, L. 1921: La fourmi d'Argentine Iridomyrmex humilis
var. arrogans SANTSCHI dans le midi de la France. – Annales
des Épiphyties 7: 237-265.
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.
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:
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.
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), <
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://
=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:
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.
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,
<>, retrieved on 20 April 2009.
RADCHENKO, A. 2005: Monographic revision of the ants (Hyme-
noptera: Formicidae) of North Korea. – Annales Zoologici 55:
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.
ROBINSON, W.H. 2005: Handbook of urban insects and arach-
nids. – Cambridge University Press, Cambridge, MA, 480 pp.
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.
J.W. & BRENNER, G.J. 1998: Non-indigenous ants at high ele-
vations on Mauna Kea, Hawaii. – Pacific Science 52: 228-236.
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.
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.
... bicarinatum and T. caldarium) are now present in Santa Maria. Both C. mauritanica and T. caldarium do not seem to have significant impacts on native biodiversity (Wetterer 2012, Wetterer andHita Garcia 2015), but T. bicarinatum and, particularly, the Argentine ant L. humile, are serious threats to island native invertebrates and natural ecological processes and have also been reported as agricultural pests (Wetterer 2009, Wetterer et al. 2009). The severe consequences of Argentine ant invasion on local biodiversity have been reported from many areas around the world, including oceanic islands, but their effects remain poorly understood in Macaronesian archipelagos (Holway et al. 2002, Wetterer and Espadaler 2010, Boieiro et al. 2018a, Boieiro et al. 2018b). ...
... bicarinatum and T. caldarium) are now present in Santa Maria. Both C. mauritanica and T. caldarium do not seem to have significant impacts on native biodiversity (Wetterer 2012, Wetterer andHita Garcia 2015), but T. bicarinatum and, particularly, the Argentine ant L. humile, are serious threats to island native invertebrates and natural ecological processes and have also been reported as agricultural pests (Wetterer 2009, Wetterer et al. 2009). The severe consequences of Argentine ant invasion on local biodiversity have been reported from many areas around the world, including oceanic islands, but their effects remain poorly understood in Macaronesian archipelagos (Holway et al. 2002, Wetterer and Espadaler 2010, Boieiro et al. 2018a, Boieiro et al. 2018b). ...
Full-text available
The data we present consist of an inventory of exotic arthropods, potentially invasive, collected in exotic and mixed forests and disturbed native forest patches of the Azores Archipelago. The study was carried out between 2019 and 2020 in four islands: Corvo, Flores, Terceira and Santa Maria, where a total of 45 passive flight interception SLAM traps were deployed, during three to six consecutive months. This manuscript is the second contribution of the “SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the Natural Forest of Azores”. We provide an inventory of terrestrial arthropods belonging to Arachnida, Diplopoda, Chilopoda and Insecta classes from four Azorean islands. We identified a total of 21,175 specimens, belonging to 20 orders, 93 families and 249 species of arthropods. A total of 125 species are considered introduced, 89 native non-endemic and 35 endemic. We registered 34 new records (nine for Corvo, three for Flores, six for Terceira and 16 for Santa Maria), of which five are new for Azores, being all exotic possibly recently introduced: Dieckmanniellus nitidulus (Gyllenhal, 1838), Gronops fasciatus Küster, 1851, Hadroplontus trimaculatus (Fabricius, 1775), Hypurus bertrandi (Perris, 1852) (all Coleoptera, Curculionidae) and Cardiocondyla mauritanica Forel, 1890 (Hymenoptera, Formicidae). This publication highlights the importance of planted forests and disturbed native forest patches as reservoirs of potentially invasive arthropods and refuges for some rare relict endemic arthropod species.
... As most invasive ants, its nesting site plasticity allows them to invade human constructions (Lee 2002), like settlements or boats docks (Carpintero & al. 2003, Rizali & al. 2010, where it can find a stable climate and a constant source of food and water. These abiotic requirements, together with ports of entries as the main invasion pathway (Corin & al. 2007, shape its distribution and expansion along coastal areas in Southwestern Europe (Espadaler & Gomez 2003, Gomez & Espadaler 2006, Blight & al. 2009, Wetterer & al. 2009). ...
... Factors including genetic drift resulting from bottlenecks, new selective pressures (Tsutsui & al. 2000, Giraud & al. 2002, high aggressiveness, and high diet breadth have been discussed (Blight & al. 2012, Seko & al. 2021). However, differential expansion of the Main Supercolony could also be related to its invasion history (Wetterer & al. 2009) including secondary introductions, which are common in invasive ants (Bertelesmeier & al. 2017(Bertelesmeier & al. , 2018. In addition, other factors related to environmental suitability could explain differences in patterns of spread. ...
Full-text available
The Argentine ant is an invasive species that has spread all over the world and is organized in several supercolonies. While there are many studies about factors promoting the expansion of the species, little is known about the factors affecting the variation in spread among the different supercolonies. We examined the environmental and spatial variables affecting the invasion of the Argentine ant on three islands of the Mediterranean Sea (Corsica, Ibiza, and Formentera) and in the three European supercolonies that inhabit them (Main European, Corsican, and Catalonian). We used data from two sampling periods, nine years apart in the case of Corsica and 12 years in the case of Ibiza and Formentera, coupled with historical data of first detection dates and locations on islands of Southwestern Europe. Along the coast of the three islands, we sampled each beach to detect the presence of the Argentine ant and used aggression assays to identify the supercolony they belonged to. The Argentine ant expanded its range on all three islands. Although the three supercolonies maintained their same locations and expanded to new locations, the highest expansion for the Main Supercolony was on Ibiza and Formen-tera and for the Corsican Supercolony on Corsica. Interestingly, the Argentine ant did not dominate at all our study sites. On one third of the beaches of Ibiza and Formentera, it co-occurred with native ant species even after 12 years. Human presence affected the likeliness of a beach to be invaded on Ibiza and Formentera. On Corsica, beaches that had already been invaded before our study or were invaded during our study were the ones with lower distance to already invaded beaches, suggesting the importance of secondary introductions in the local expansion of the Argentine ant. Our findings help to understand the dynamics of invasions of the Argentine ant and its different supercolonies. Long-term studies at many invaded sites are of great importance in order to obtain general patterns of the spread of this global invader.
... Research on the global invasion history of the tropical fire ant suggests a corresponding spread of S. geminata from Mexico via Manila to Taiwan, and from there throughout the Asia-Pacific countries (22). Linepithema humile has been introduced to many temperate, tropical, and subtropical regions in the Asia-Pacific, although its distribution is somewhat patchy (91). We can expect this species to continue to spread in the region, especially in parts of southern China that have appropriate Mediterranean-like climates, where this exotic ant would be expected to have a great impact (91). ...
... Linepithema humile has been introduced to many temperate, tropical, and subtropical regions in the Asia-Pacific, although its distribution is somewhat patchy (91). We can expect this species to continue to spread in the region, especially in parts of southern China that have appropriate Mediterranean-like climates, where this exotic ant would be expected to have a great impact (91). ...
Human activity has facilitated the introduction of many exotic species via global trade. Asia-Pacific countries comprise one of the most economically and trade-active regions in the world, which makes it one of the most vulnerable regions to invasive species, including ants. There are currently over 60 exotic ant species in the Asia-Pacific, with the red imported fire ant, Solenopsis invicta, among the most destructive. Exotic ants pose many economic and ecological problems for the region. Countries in the Asia-Pacific have dealt with the problem of exotic ants in very different ways, and there has been an overall lack of preparedness. To improve the management of risks associated with invasive ants, we recommend that countries take action across the biosecurity spectrum, spanning prevention, containment, and quarantine. The creation of an Asia-Pacific network for management of invasive ants should help prevent their introduction and mitigate their impacts. Expected final online publication date for the Annual Review of Entomology, Volume 67 is January 2022. Please see for revised estimates.
... El seguimiento de hormigas en Madrid ha servido también para revelar el alcance de la presencia de la hormiga argentina, Linepithema humile (Mayr, 1868), en numerosos puntos de la ciudad (López-Collar y Cabrero-Sañudo 2021) (Fig. 3K). Esta especie exótica es ampliamente conocida por su carácter invasor fuera de su rango nativo (Wetterer et al. 2009) y llega a suponer un problema serio tanto en entornos naturales (Carpintero et al. 2014) como urbanos (Touyama et al. 2003), al desplazar a las especies nativas y provocar perjuicios económicos relacionados con el mantenimiento de plagas de hemípteros. En la ciudad de Madrid todavía es pronto para lanzar un veredicto acerca de las consecuencias ambientales de la invasión por parte de la hormiga argentina, pero sin duda el grado de expansión y la trayectoria histórica (Collingwood y Yarrow 1969;Martínez et al. 1997;Ruiz-Heras et al. 2011) son preocupantes. ...
Full-text available
Bioindicators have proven to be very useful tools for evaluating the state of disturbance or maturity of ecosystems, as well as for monitoring and detecting changes in the environment. Considering a series of criteria that justify the quality of the bioindicator groups, various arthropod taxa could be considered optimal. There are several studies that use arthropods as bioindicators, especially in urban areas. We present some monitoring experiences carried out in the last ten years by the UCM Biodiversity Monitoring Group at the Moncloa Campus, a peri-urban area located in the northwest of the city of Madrid, related to the monitoring of populations of arthropods (butterflies, ants, and dragonflies). Finally, some recommendations and future perspectives for the use of arthropods as bioindicators in urban areas are summarized
... The Argentine ant, Linepithema humile (Mayr, 1868), is a well-known and widely studied organism due to its highly potential as an invasive species (Wetterer et al. 2009;GISD 2015). This ant presents a wide range of strategies, such as its characteristic interspecific aggressiveness, polygynic and polydomic colonies and a large number of individuals per nest, which gives it a greater capacity to establish new settlements, indirectly and profusely aided by humans (Suarez et al. 2001;Carpintero et al. 2004;Ward et al. 2005). ...
Full-text available
New geolocated records of the invasive ant Linepithema humile (Mayr, 1868) are added to the previous references for the city of Madrid and its surroundings, and the possible causes of the occurrence and permanence of this species in urban areas are discussed. The data collection corresponds to a series of samplings carried out for the last three years in green areas of the city, bibliographic searches, citizen science platforms and personal communications. To date, eleven locations in the urban area of Madrid and four points outside the city have been registered. The city of Madrid is undergoing a colonisation by the Argentine ant, although it is not widespread yet, since observations over time and space are isolated and apparently unrelated. However, this species has a great capacity to disperse and establish new colonies, mainly human-mediated through the transport of goods, plants, gardening tools, etc. Considering the numerous colonizable urban green areas in the city that can provide the necessary conditions for its expansion , the Argentine ant should not be underestimated, and immediate action is strongly recommended.
... The Argentine ant (Linepithema humile, Mayr 1868) is one of the most devastating invasive species in the world (Holway et al. 2002). Native to South America, it has spread worldwide, mainly in regions with Mediterranean climate (Suarez et al. 2001;Wetterer et al. 2009;Vogel et al. 2010). The Argentine ant has a strong economic impact and also a heavy ecological impact on the invaded ecosystems, because it does not only displace the local arthropod fauna (Bolger et al. 2000;Holway and Suarez 2004), but it also causes a series of cascade effects in the rest of ecosystem, from plants (Christian 2001;Blancafort and Gómez 2005) to vertebrates (Suarez et al. together with dolichodial and (Z)-9-hexadecenal (Choe et al. 2012) -, Welzel et al. (2018) revealed that iridomyrmecin (and dolichodial) function as defensive allomones, causing high levels of irritation in the heterospeci c competitors of the Argentine ant, such as the California harvester ant (Pogonomyrmex californicus). ...
Full-text available
One of the main traits of invasive ants is the formation of supercolonies, large networks of polygynous nests lacking intraspecific competition, which allows them to reach high densities that facilitate their spread. However, different supercolonies exhibit different success in expanding along the world. Here, we explore whether the main chemical defensive compound of the Argentine ant could play a role in the differential invasiveness of supercolonies. We assessed differences in the amount of iridomyrmecin among supercolonies in the native range and in three invasive supercolonies: the Main supercolony (the most extended worldwide), and the Corsican and the Catalonian supercolonies (both with a restricted local distribution in Europe). We found that even if the amount of iridomyrmecin varied greatly between invaded regions in the three supercolonies in Europe and the native supercolonies in South America, the differences did not seem related to the success of invasion. The amount of iridomyrmecin of the Main supercolony was the lowest while the highest corresponded to the Corsican supercolony, with the Catalonian having intermediate values. This suggests that the success of a given invasive supercolony may not be explained by higher quantities of this defensive compound. Alternatively, reducing iridomyrmecin quantities in the invasive range could lead to more investment in other fitness traits that increase the invader's competitive ability. Our results open the way for exploring the contribution of defensive compounds in the competitive ability and spread of this global invader.
... Argentine ants (linepithema humile (Mayr, 1868)), which are native to the Paraná River drainage area in South America, are included among the 100 most hazardous invasive species in the world (Lowe et al., 2000) and have established colonies worldwide (wetterer et al., 2009;Roura-Pascual et al., 2011). The successful expansion of this species is attributed to a highly polygynous (i.e., many reproductive queens) and unique social structure in which individuals mix freely among separate nests (Helanterä et al., 2009), referred to as supercoloniality. ...
Full-text available
linepithema humile is one of the most damaging invasive species worldwide. Although chemical control strategies have proven effective for l. humile, the susceptibility of these invasive ants to the insecticide fipronil differs markedly among genetically different supercolonies. In Japan, five mitochondrial l. humile haplotypes were identified from eleven prefectural regions and cities as of 2010. In 2012, a new population was found in Okayama Prefecture. Here, we analyzed mitochondrial DNA from l. humile workers from the Okayama population to better understand the genetic structure of ants in Japan and develop effective control strategies. According to COI-COII and cytochrome b gene sequences, the l. humile Okayama population haplotype was consistent with the 'Japanese main' supercolony-the most invasive supercolony worldwide. Hence, we believe that the Okayama population (Japanese main supercolony) can be easily eradicated because of its early invasion stage, relatively limited distribution range and high sensitivity to fipronil.
... Of these species, one of the most well-known is the Argentine ant (Linepithema humile Mayr; subfamily Dolichoderinae). Originating from South America, L. humile can now be found across six continents and several oceanic islands (Suarez et al. 2001;Wetterer et al. 2009). It is particularly common in regions with a Mediterranean or subtropical climate (Tsutsui et al. 2000). ...
Full-text available
Invasive alien species pose a serious threat to the integrity and function of natural ecosystems. Understanding how these invaders alter natural communities is therefore an important aspect in predicting the likely future outcomes of biological invasions. Many studies have documented the consequences of invasive alien species on native community structure, through the displacement and local extinction of native species. However, sampling methods and intensities are rarely standardised across such studies, meaning that it is not clear whether differences in response among native communities to the same invader species are due to biological differences between the invaded regions, or differences in the methodologies used. Here we use a matched sampling methodology to compare the effects of the Argentine ant ( Linepithema humile Mayr) on native ant community assemblages in two distinct biogeographical regions that share similar ecologies: Girona (Spain) and Jonkershoek Nature Reserve (South Africa). We found a strong negative association between L. humile presence and native ant species richness within both geographic regions. However, the effects differed between the two study regions: in Girona, a single native ant species ( Plagiolepis pygmaea ) persisted in invaded sites; by contrast, substantially more native ant species persisted at invaded sites in Jonkershoek Nature Reserve. In addition, in Jonkershoek Nature Reserve, the abundance of certain native species appeared to increase in the presence of L. humile . This study therefore demonstrates the potential variable effects of an invasive species in contrasting locations within different biogeographical regions. Future work should explore the causes of this differential resistance among communities and expand standardised sampling approaches to more invaded zones to further explore how local biotic or abiotic conditions of a region determine the nature and extent of impact of L. humile invasion on native ant communities.
Full-text available
The Argentine ant ( Linepithema humile ) is one of the most damaging and widespread invasive ant species worldwide. However, control attempts often fail due to insufficient bait uptake, or bait abandonment. Increasing preference for, and consumption of, is thus an important requirement for successful control. Associative learning and within-nest information transfer might be a potential tool for achieving this goal. Here, we conducted a detailed and systematic investigation of olfactory learning and side learning in Argentine ants. The ants showed very strong and rapid side learning, choosing the correct arm in a Y-maze 65% of time after just one visit, and 84% correct after two. Odour learning was even more rapid, with just one visit to a flavoured food source, reached by a scented runway, leading to 85% choices for the corresponding scent on a Y-maze. Further experiments demonstrated that having two cues (runway odour and food flavour) does not improve learning significantly over just one cue. This rapid learning is long-lasting, with one exposure to a runway odour associated with a reward resulting in a strong preference (73%) for this odour even after 48 hours. Food flavour information is transferred efficiently between nestmates in the nest, driving preference: naïve ants housed with ants fed on flavoured food show a strong preference (77%) for that odour after 24 hours. Our results demonstrate the impressive learning abilities of Linepithema humile , which coupled with efficient intranidal information transfer and strong use of pheromonal recruitment may help explain their ability to discover and then dominate resources. However, these strengths could potentially be used against them, by exploiting learning and information transfer to increase toxic bait uptake during control efforts. Steering ant preference by leveraging learning might be an underappreciated tool in invasive alien species control.
The Argentine ant Linepithema humile is reported in Okinawa Prefecture for the first time. Only one individual of the species was collected through a fire ant survey at the Naha Port International Container Yard. At the time of this reporting, colonization of this species has not been found in Okinawa. The low similarity of ant community in the container yard between survey dates suggests that many ants may be transported with ship-containers to/from Okinawajima Island through Naha Port, which is the primary international port of Okinawa Prefecture. The previous research findings suggest that further surveillance and countermeasure are necessary to prevent the invasion and colonization of Argentine ants in Okinawa Prefecture.
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.
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.
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.
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.
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.
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.
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.