Pogonomyrmex maricopa
Encyclopedia
The Maricopa harvester ant, Pogonomyrmex maricopa, is one of the most common species of harvester ant
species found in Arizona
, USA. Its venom is believed to be the most toxic insect venom in the world.
Their nest mounds are likely to incorporate rocks and gravel
. The ants construct cemented caps on the sand mound nests in a fine sand dune
area. The caps are approximately 60% calcium carbonate
that is transported from the underlying calcium carbonate layers, and protect the nest structure from being eroded away during high-wind periods. Partial erosion of the cemented caps adds calcium carbonate to the sand dune soils.
Like many venomous insects, the venom of the Maricopa harvester ant consists of amino acid
s, peptide
s, and protein
s. This may also encompass alkaloid
s, terpene
s, polysaccharide
s, biogenic amine
s, and organic acid
s. The most notable component found in the venom of the Maricopa harvester ant is that of the alkaloid
poison—this releases an "alarm" pheromone
that chemically alerts other ants in the vicinity. This is an example of chemical signaling, which explains why ants all appear to sting at once. The venom can also contain allergenic
proteins that are otherwise known to set off a potentially lethal immune response
in certain victims.
Similar to the two-part process of the fire ant
bite and sting, the harvester ant will attach to the victim with its mandibles
, and so proceed by pivoting around the site, allowing the Maricopa harvester ant to repeatedly sting and inject venom into the region.
The Maricopa harvester ant plays a major role in decomposition
by dragging dead carcasses of insects underground and thereby enriching soil for plants and crops.
Another sighting, recorded on July 26, 2001, in West Dog Canyon in Guadalupe Mountains National Park
, Texas, described the ant-hill as consisting of excavated chambers that had a possible depth of 7 feet (2.1 m) or more.
These ants are also seen in New Mexico.
Harvester ant
Ants known as Harvester ants include:species*Red harvester ant *Florida harvester ant *Maricopa harvester ant , the most venomous insect in the world....
species found in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, USA. Its venom is believed to be the most toxic insect venom in the world.
Their nest mounds are likely to incorporate rocks and gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
. The ants construct cemented caps on the sand mound nests in a fine sand dune
Dune
In physical geography, a dune is a hill of sand built by wind. Dunes occur in different forms and sizes, formed by interaction with the wind. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind...
area. The caps are approximately 60% calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
that is transported from the underlying calcium carbonate layers, and protect the nest structure from being eroded away during high-wind periods. Partial erosion of the cemented caps adds calcium carbonate to the sand dune soils.
Venom and attack method
The toxicity of the venom of the Maricopa harvester ant is well known. Its LD50 value is 0.12 mg/kg (injected intravenously in mice); 12 stings can kill a 2 kg rat. In comparison, the LD50 of the honey bee is 2.8 mg/kg — more than 20 times weaker. In humans, a Pogonomyrmex sting produces intense pain that can last up to 4 hours.Like many venomous insects, the venom of the Maricopa harvester ant consists of amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s, peptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
s, and protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s. This may also encompass alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
s, terpene
Terpene
Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, though also by some insects such as termites or swallowtail butterflies, which emit terpenes from their osmeterium. They are often strong smelling and thus may have had a protective...
s, polysaccharide
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
s, biogenic amine
Biogenic amine
-Examples:Some prominent examples of biogenic amines include:* Histamine - a substance derived from the amino acid histidine that acts as a neurotransmitter mediating arousal and attention, as well as a pro-inflammatory signal released from mast cells in response to allergic reactions or tissue...
s, and organic acid
Organic acid
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are relatively stronger acids. The relative stability of the conjugate...
s. The most notable component found in the venom of the Maricopa harvester ant is that of the alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
poison—this releases an "alarm" pheromone
Pheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
that chemically alerts other ants in the vicinity. This is an example of chemical signaling, which explains why ants all appear to sting at once. The venom can also contain allergenic
Allergen
An allergen is any substance that can cause an allergy. In technical terms, an allergen is a non-parasitic antigen capable of stimulating a type-I hypersensitivity reaction in atopic individuals....
proteins that are otherwise known to set off a potentially lethal immune response
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
in certain victims.
Similar to the two-part process of the fire ant
Fire ant
Fire ants are a variety of stinging ants with over 285 species worldwide. They have several common names, including ginger ants, tropical fire ants and red ants.- Appearance :...
bite and sting, the harvester ant will attach to the victim with its mandibles
Mandible (arthropod)
thumb|250px|The mandibles of a [[Bull ant]]The mandible of an arthropod is either of a pair of mouthparts used for biting, cutting and holding food. Mandibles are often simply referred to as jaws. Mandibles are present in the extant subphyla Myriapoda , Crustacea and Hexapoda...
, and so proceed by pivoting around the site, allowing the Maricopa harvester ant to repeatedly sting and inject venom into the region.
The Maricopa harvester ant plays a major role in decomposition
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
by dragging dead carcasses of insects underground and thereby enriching soil for plants and crops.
Sightings
Colonies of harvester ants have been reported in El Paso County, Texas. One sighting, recorded on August 14, 2004, reported a rather large Pogonomyrmex maricopa nest, measuring 6 by, around which all surrounding vegetation had been cleared. The person who reported the sighting noted the length of the Maricopa harvester ant at approximately one centimeter.Another sighting, recorded on July 26, 2001, in West Dog Canyon in Guadalupe Mountains National Park
Guadalupe Mountains National Park
Guadalupe Mountains National Park is located in the Guadalupe Mountains of West Texas and contains Guadalupe Peak, the highest point in Texas at in elevation. It also contains El Capitan, long used as a landmark by people traveling along the old route later followed by the Butterfield Overland...
, Texas, described the ant-hill as consisting of excavated chambers that had a possible depth of 7 feet (2.1 m) or more.
These ants are also seen in New Mexico.