Argentine Ant
Argentine Ant
Latin Name: Iridomyrmex humilis
Traits: It is a small, dark-colored ant about 3 mm (1/8 inch) long that invades homes hunting for food and water..
Color: dark-colored
Other: It is also light to dark brown in color, and it has six legs, as with other insects. The Argentine ants' antennae have twelve segments. The thorax joins the stomach by a thin pedicel, a thin stalk.
Where can they be discovered? Outdoors in soil, under timber, slabs, debris, mulch, or in branches and cavities of trees and shrubs
Shallow, 1- to 2-inch deep mounds in open, often disturbed habitats, either moist or dry
The most common ant in southern California is the Argentine ant (Iridomyrmex humilis). This ant can likewise be found in the lower eastern United States area. As reported by Wild (2004), this species was originally described in the genus Linepithema by Mayr in 1866; as a consequence, the right binomial ought to be Linepithema humile. It is a tiny, dark-colored ant about 3 mm (1/8 inch) long that invades homes looking for food and water. They are specifically fond of sweets, but will feed upon practically any food. They love hard boiled eggs and carry small yellow clumps of yolk back to their nest in endless ant columns.
These ants are exceedingly well adapted to urbanized areas of the United States with mild climates and well-watered gardens. They pose an important threat to native wildlife by upsetting sensitive food webs. They are specifically formidable due to their aggressive behavior and the massive size of their colonies that can literally "team up" with other colonies.
If you live in southern California, you probably have noticed endless single file columns of uninvited six-legged guests strolling through your house. They follow a pre-marked pheromone "scent" trail firstly laid down by scouts who were looking for goodies in your pantry. Although they choose to outdoor lifestyle, they primarily enter houses for food and water. They're fond of sweets, tuna, syrups (even cough syrup), juices, eggs, dead spiders and rodents, puke, faeces and almost any other living tissue they can find. They are fundamentally scavengers and they play a valuable role in the natural ecosystem–but preferably in Argentina. In hot, dry weather they frequently search your home for water, including washroom faucets and drains. I once followed an ant safari into my bathroom where they were neatly stacking their precious cargo of tiny eggs inside my toilet tank. They also relish the "honeydew" secretion of aphids, and safeguard their aphid friends from natural predators. In the fall months as the nights get cold, they once again seek the warmth and shelter of your cozy home.
The first Argentine ants set foot on U.S. soils in the late 1890's, as coffee ships from Brazil unloaded their load in New Orleans. Being prolific breeders and constantly busy, they moved across the southern half of the US. A single colony may contain 10,000 female workers, and there may well be many hundreds of colonies around your house; the entire number of ants could easily reach a million. Although they cannot sting, they can bite; however, they are merely about 3 mm long and there tiny mandibles are too small to hurt humans. But, globally of insects, these ants are truly a living terror. They are very aggressive and readily overtake other ant species, even ants that are much larger and with powerful stings. Argentine ants are relentless and merely outnumber their adversaries until the enemy colony is destroyed. They even attack paper wasp nests under the eaves of a house, forcing the enormous wasps to flee their nests in terror. Even nests of large carpenter bees are no match for these relentless ants. A "killer bee" nest probably could not withstand an encroachment in Argentine ants. They also will attack bird nests, driving off the mom bird and killing the helpless young. One possible redeeming quality about these little warriors is that they could attack dry- timber (aerial) termite colonies in your home. I have experienced this Lilliputian massacre in a termite infested table in the Palomar College greenhouse.
Most ant colonies are very highly territorial, and will fight different colonies of the same species. Since Argentine ants in the US originated from the original colonizers in Louisiana, they are all closely related with alike DNA. They evidently will accept ants from different colonies as guests of their gigantic family. In fact, Argentine ants from different colonies will in reality "team up" and attack together in vast swarms. They only outnumber and overpower their enemy.
Argentine ants have become an essential threat to the coast horned lizard (Phrynosoma coronatum) in southern California. The primary food source for these endangered lizards are native harvester ants, particularly the California harvester ant (Pogonomyrmex californicus). I spent many years observing this fascinating red ant while growing up in San Gabriel Valley, and I can personally testify that it has a agonizing sting. As of 2006, this large red ant is seldom seen in urbanized areas of coastal southern California.
California harvester ant (Pogonomyrmex californicus), primary diet of coast horned lizard.
Urbanization has certainly been a factor in the demise of California harvester ants, but a greater factor leading to the liquidation of native ants and coast horned lizards is the aggressive Argentine ant. Evidently the horned lizard is not fond of Argentine ants, and is in reality attacked by them in enormous swarms. Colonies of Argentine ants need a damp area to survive, and have not invaded some of the dry habitats where native harvester ants and desert horned lizards (P. platyrhinos) still live. Naturally, they can readily colonize urbanized desert areas inhabited by people. Well-watered gardens with stepping stones and concrete slabs provide the idea living requirements for these ants. In their native Argentina they live under rocks.
Coast horned lizard (Phrynosoma coronatum).
Argentine ants are a terrible nuisance in gardens and orchards as they tend and protect scale insects and aphids. They even carry aphids to the tender buds of your prized roses. In return, the ants consume a sweet secretion from the aphids called "honeydew." In addition, swarms of these ants will invade orchard trees, destroying the fruit crop. This is particularly serious in figs (Ficus carica) where the symbiotic pollinator wasps are destroyed.
Metallic green fig beetles (Cotinus texana) gorging themselves inside a fleshy, ripe syconium of the Calimyrna fig (Ficus carica). Although masses of minute, aggressive Argentine ants (Linepithema humile) are likewise foraging in the syconium (white arrow), the beetles are safe by their tough, impervious exoskeleton. These attractive beetles spend their juvenile larval stage in the ground, often beneath manure piles, compost and haystacks.
According to entomologist David Faulkner, if you've a 10 x10 foot (3 x 3 m ) patio slab, you may have a million or more individuals and possibly 20 or 30 queens. They get along fine because they're all linked with the original colonizers in Lousiana, perhaps from the original gravid (pregnant) female who arrived there. Workers live a month or more as adults, but queens live up to 10 years or longer. With other ants, when the queen dies, the one-queen colony dies because no more ants are being produced. With multi-queen Argentine ants, another queen simply moves in and takes over the role of the deceased queen. In point of fact, a queen from San Diego would probably be accepted in a colony elsewhere in California.
Argentine ants (Linepithema humile): A wingless queen and several workers. Although these ants are merely 3 mm long, they're very aggressive and quickly annihilate other ant species, even larger ants with powerful jaws and stings. They overpower other species by their sheer numbers. Argentine ants in the U.S. are descendants of original colonizers that entered Louisiana in the late 1890's, as coffee ships from Brazil unloaded their freight in New Orleans. U.S. populations are so closely associated that different colonies with multiple queens can literally merge together into supercolonies. Image taken with Nikon D-90 and 60mm Micro Nikkor AF-S F/2.8G ED Macro Lens using a Phoenix Ring Flash; hand-held at 640 ISO, F-32, 1/125th sec.
In their native homeland of Argentina, different colonies of Argentine ants are not so friendly to each other because their DNA has developed much greater variation. Neighboring colonies may fight each other, even though they are simply 200 yards (200 m) apart. Also there are lots of native predators in Argentina, including fungal leeches and bacterias. The narrow genetic variability that has kept all the California populations on friendly terms may eventually backfire because of extreme inbreeding. Perhaps some day these ants may not have the genetic variability to adjust to a changing environment.
How To Control Invasions of Argentine Ants"
Empty your trash often and make sure your home has no crums and food particles that might attract ants. Ensure that food containers are tightly closed, without residual traces of the food on the sides of containers. These ants can even get into screw-top jars without seals. They follow the spiral threads until they're inside!
Avoid using toxic aerosol insecticides inside your house–unless you don't care about your lungs or your bone marrow.
Try spraying a deodorant detergent (Pine Sol