Ant Crazy Ant/ Long legged
Ant Big Headed Ant
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are invasive ants so successful and detramental in Hawaii?
Hawaiian archipelago is extremely isolated. Through evolutionary history,
after the arrival of a single ancestor, high levels of radiation occurred.
In the case of arthropods, this evolution was often times accompanied
by extreme changes in morphology, ecology, and behavior. These radiations
have resulted in high endemism; over 97% of the 5,735 decribed native
species of arthropods in Hawaii are endemic (Roderick and Gillespie 1998).
There are no endemic or native ant species in Hawaii (Wilson and Tayler
1967). The more than forty species of ants now established on Hawaii were
introduced by humans during the last hundred years (Reimer et al. 1990).
The presence of ants on Hawaii is very recent in light of millions of
years of evolution (Reimer 1994). As a result, the native terrestrial
arthropods have not developed defenses against ants (Reimer et al. 1990)
and no specialized ant predators are present in the Hawaiian archipelago
(Reimer 1994). These favorable conditions enabled ants to spread rapidly
resulting in devastating consequences, primarily in low elevations, for
Hawaii (Reimer 1994).
Of the 3,055 invasive arthropods now present on Hawaii ants are considered
to be some of the most destructive (Roderick and Gillespie 1998).
are the impact of Invasive Ants on Hawai‘i’s native habitat?
- Endemic arthropod
populations have been decimated at lower elevations by ant predation
(Reimer et al. 1990).
ants may effect vertebrates by eliminating their invertebrate food sources.
This exploitative competition may be partly responsible for the disapperance
of most native birds in Hawaiian lowlands (Banko and Banko 1976 in Wetterer
1998). High densities of ants in highlands may have contributed to the
exclusion of Palila (an endangered Hawaiian endemic bird).
disperse seeds of alien plants (Howarth 1984).
are seed predators of native plants (Bond and Slingsby 1984).
participate in synergistic relationships with other invasive species.
For instance, many pestiferous ant species tend alien honeydew-producing
homopterans, like aphids, mealy bugs, and treehoppers that feed on native
plants and need mutualistic ants to disperse and protect them from predators
are the economic impacts of ants?
Ants can be pests in agriculture
(Reimer 1990) and have caused hundreds of thousands of dollars of damage
in certain areas of the United States (Adams 1986 in Thompson 1990). In
Hawaii, the sugar industry uses drip irrigation systems. Invasive ants
chew through the plastic tubing and enlarge pre-existing holes, flooding
damaged areas and causing erratic irrigation of the fields. Damage is
often so severe that tubing needs to be replaced, and frequently whole
crops can be lost due to severe water shortages (Chang and Ota 1990).
Ants also contribute to economic losses by tending honeydew producing
homopterans that damage crops (Reimer 1990).
characteristics make tramp ants successful?
Tramp ant species are the most detrimental ants in Hawaii, and are particularly
devastating to endemic arthropods (Passera 1990). Tramp ants are virtually
impossible to eliminate once established (Forschler and Evans 1994) and
highly successful invaders, especially in areas that have been disturbed
by humans (Passera 1990). Passera (1990) outlined the following characteristics
that apply to tramp ants.
- Tramp ants tend
to be attracted to unstable environments and move their colonies in
response to weather, physical disturbance and dietary change (depletion
of or finding new resources).
- Tramp ants are
unicolonial: there is little intraspecific aggression between ants
from different nests.
- The absence of
intraspecific aggression is tied to strong interspecific aggression,
when tramp ants
come in contact with other arthropod species they usually drive
them away. Tramp species will compete with and displace other tramp
- Polygyny is a
characteristic of tramp ants. Nestmate queens do not appear to be hostile
toward each other, and there is no observable dominance hierarchy.
- Mating occurs
in the nest, and colony reproduction occurs by budding, where mated
queens and workers depart on foot to establish a colony a few meters
away. Populations spread slowly, but very thoroughly. Long distance
dispersal occurs passively (ants on drift wood) or through
- Tramps ants tend
to be very small, always less then 3.5 mm in length.
- The queens of
tramp ants have very short life spans, tramp queens rarely live longer
than one year. This is not a disadvantage because tramp species produce
and rear new queens almost year round at a fairly high rate.
- Worker sterility
is very common.
What is the distribution of ants in Hawaii?
Ants are found on all 8 main islands, and each of the largest islands
of the Northwest Hawaiian Islands chain. All of the introduced ant species
have been collected on Oahu, probably because it is their major port of
entry. Most of the species are in the warmer, dry (0- 120 cm precipitation
per year) to mesic (120- 250 cm precipitation) lowlands. Part of this
distribution may be tied to the high levels of human disturbance in the
lowlands in the form of land clearing, fire, agriculture, and urbanization
(Reimer et al 1990).
are ant vectors?
All invasive ants reached Hawaii through human commerce, (Wilson and Tayler
1967) then lived in more disturbed agricultural and residential lowlands
before spreading to the highlands. This might explain why invasive ants
are far more established in the low lands (Wetterer et al 1998).
ants on the islands controlled?
- Biological control
and using toxic baits and sprays are the only feasible methods of ant
control in natural environments (Reimer et. al 1994) (Changand Ota 1990).
- Biological control
today is problematic and ant eradication is virtually impossible (Patterson
- Ants have developed
techniques to protect their colonies from pathogens, parasites and predators.
Ants are impeccable house cleaners and personal groomers, they
quickly recognize invaders and remove them from the colony, and they
secrete in their venom chemicals that have antibiotic and anti-fungal
properties. (Patterson 1994).
- Although in residential
and agricultural settings, in Hawaii, ants have been successfully
controlled with toxic bates and sprays, wide spread control has not
been attempted (Reimer et. al 1994) (Changand Ota 1990).
- Commonly used
chemical barriers and repellant tend not to affect queens and non-foraging
colony members because the toxins are not brought into the nest. (Forschler
and Evans 1994).
- Delayed action
insecticide has been used more successfully in controlling populations
and requires less toxicant leading to less contamination then other
insecticides, yet requires that foraging ants take bate material back
to the colony and feed the brood and queen (Forschler and Evans
- Baits and sprays
can lead to environmental contamination (Forschler and Evans 1994) and
care needs to be taken not to poison non-target organisms (Reimer
ants are causing the greatest damage to Hawaii?
Three of the following ants have been defined as tramp species and are
probably the most detrimental invasive ants on Hawaii. All three are extremely
aggressive and tend to have mutually exclusive territories (Flucker and
Beardsley 1970). The big headed ant (Pheidole megacephala), the
long legged ant also referred to as the crazy ant (Anoplolepis longipes)
occupy primarily lowland areas. The argentine ant (Linepithema humile)
is found in highland areas (Wetterer et al 1998).
not described in detail here, it is important to note that although it
has not reached Hawaii yet, another tramp ant, the red imported fire ant
(Solenopsis invicta), which invaded the United States in the1930's
(Thompson 1990) and originates in South America (Porter et al. 1990) reached
the California coast in 1998.. Many of Hawaii’s imports come from
California, including nursery stock, making the possibility of an invasion
of this species fairly high. If this ant does reach Hawaii it is very
likely that it will become established, and there is a high probability
it will displace the current invasive tramp
ants (Loope and Reeser 2001).
of the Solenopsis invicta
- In the continental
United States Solenopsis invicta has competitively replaced
other ant species as well as significantly reduced densities and species
richness of other arthropods (Porter 1990).
invicta has caused significant economic losses. By 1948 it was
shown to have caused more then $500,000 worth of damage to corn,
potatoes, and cabbage farms, in Mississippi alone (Adams 1986 in Thompson
invicta has a very powerful and painful sting that can be deadly
to those who are hyper-allergic; at least 83 people have died in
the USA, from being stung by Solenopsis invicta (Loope and
Solenopsis invicta has been shown to cause significant discomfort
to humans it seems like it’s invasion could be devastating because
much of Hawaii's economy is based on tourism (Loope and Reeser 2001).
humile is a medium sized ant, roughly 2.5 mm in size with reddish
black coloring and a 1- segmented waist that has a sharp pointed node.
It does not have any standing hairs on the thorax (Huddleston and Flucker
1968). In Hawaii this is the primary pest ant in higher elevations (above
900 M) yet can be found at lower elevations as well (Reimer 1994).
humile originated in South America (Wilson and Tayler 1967) and has
invaded every continent (Passera 1990).
In all cases
of introduction the vector of Linepithema humile has been human
commerce. It was introduced into France with tropical plants shipped from
South America, and to South Africa with animal forage shipped from Argentina.
Argentine ants were brought to Hawaii with troops in the second world
war (Passera 1990) and were also commonly found in cargo coming from California
in the earlier part of the 20th century (Zimmerman 1941).
humile indirectly impacts vertebrate populations by eliminating
important invertebrate prey species (Banko and Banko 1976 in Wetterer
humile has been found to negatively impact invertebrate species,
most likely through directly feeding on immature and adult organisms
and competing for rock shelter (Cole et al. 1992).
humile may significantly reduce the numbers of certain endemic
pollinators of native shrubs and herbaceous plants, or cause them to
go extinct (Cole et al. 1992).
- Through predation
and interspecific competition, the Linepithema humile has taken
the place of endemic beetles as keystone predators in Haleakala
National Park (Cole et al. 1992).
humile will tend invasive honeydew producing insects, carrying
them from plant to plant, and will protect them from parasites and
predation (Zimmerman 1941).
- This ant causes
considerable trouble in houses among other things, eating food (Zimmerman
and sprays have helped control Linepithema humile populations
(Forschler and Evans 1994) and baiting in particular has been shown to
control populations on a wide scale in national parks in Hawaii (Roderick
and Gillespie 1998).
(Big Headed Ant)
Neil Reimer, Hawaii State Dept. of Agriculture
megacephala have a dark brown coloring, the soldiers have large heads
and a smooth shiny occipital region. The waist has two nodes and the propodeum
has spines. Workers are 2.2 mm long, and soldiers are 3.4-3.8 mm (Huddleson
and Flucker 1968). On Hawaii this ant is found in a great variety of habitats
from sea level to 4000 ft., although are are most common under 3000 ft.
Pheidole megacephala is the dominant ant through out the islands
(Huddleson and Flucker 1968).
megacephala originated in Africa (Wilson and Tayler 1967) and was
first reported in Hawaii in 1899 (Huddleston and Fluker 1968). This ant
has invaded almost of the humid tropics (Wilson and Taylor 1967).
is distributed through commerce
(Wilson and Taylor
- The big headed
ant indirectly impacts vertebrate populations by eliminating important
invertebrate prey species (Banko and Banko 1976 in Wetterer 1998).
- This ant actively
displaces native arthropod fauna where it is introduced (Fowler and
Robinsom 1988 in Fowler et al. 1990).
- This ant aggressively
defends nectar deterring natural pollinators from pollinating native
plants (Howarth 84).
- This ant care
takes mealy bugs that transmit wilt in Hawaiian and Costa Rican Pineapples.
Were Pheidole megacephala not present, mealy bugs and
wilt would not be a problem (Glancey et al. 1990).
- Pheidole megacephala
is a common house hold pest (Huddleson and Flucker 1968), and often
damages structures like electrical cables (Fowler 1988).
and toxic barriers have been shown to control Pheidole megacephala
populations in Hawaii (Chang and Ota 1990).
(Crazy or Long legged ant)
by Neil Reimer, Hawaii State Dept. of Agriculture
longipes is monomorphic and yellow to reddish in color with a long
slender body, long antennae and almost no standing hairs on the dorsum
of the thorax. The abdomen can be darker then the head and thorax. Anoplolepis
longipes moves extremely quickly (Huddleston and Flucker 1968). This
ant is abundant in dry areas,(Huddleston and Flucker 1968) and can also
be found at low elevations in wet forest on East Maui (Hardy 1979 in Gillespieand
longipes originated in South-East Asia (Haines and Haines 1978).
ant was distributed through commerce (Haines and Haines 1978) and was
first collected on Hawaii in 1952 (Huddleston and Flucker 1968).
longipes can be beneficial because of its competitive relationship
with other pests like cockroaches, centipedes and possibly rats (Haines
and Haines 1978).
longipes has been shown to competitively exclude native spiders
(Tetragnatha) from both native and disturbed habitats in Hawaii (Gillespie
and Reimer 1993).
- This ant tends
green scale (Coccus viridis), a honey dew producing homoteran,
which when tended occurs in high densities resulting in the growth of
sooty moulds on coffee trees. Sooty mould will greatly reduce the yield
and potentially kill the tree (Reimer 1990).
- This ant invades
homes and is a serious pest to both humans and livestock (Hains and
and poison spray are currently used to control populations of Anoplolepis
longipes and have been shown to reduce their numbers yet have not
eradicate established populations. These meathods are particularly effective
when controlling Anoplolepis longipes as a domestic nuisance
and have have prevented establishment in Praslin (an island in the Saychilles)
after a prompt report of a new infestation (Haines and Haines 1975).
Ant Group (HAG)
This informative site covers a broad range of topics amoung
others describing invasive ants, potential invasives, how to identify
invasive ants and the current research being conduced in Hawaii.
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Argentine Ant in Hawaii. Proceedings of the Hawaiian Entomological Society
Designed by: Stephanie Schiro Contact:
Last revised: 8 December 2002