Red harvester ant
Encyclopedia
The red harvester ant is a large (5–7 millimetres) ant
common in the southwest
United States
.
As with most ant species, their mating castes consist of winged alates (reproductives) that reside in the nest until weather permits them to fly away and mate. After that the male usually dies, while the now-fertilized queen returns to the ground to search for a suitable nesting site. Once she has chosen a site, she sheds her wings and begins to reproduce, creating a new colony. She produces "worker ants" for 1–20 years until her death.
Red Harvester Ants can be aggressive and have a painful sting
that spreads through the lymph node
s, sometimes causing reactions, especially in animals allergic
to their venom
. They can also bite ferociously.
Over the years, their numbers have been declining, and this has often been attributed to competition for food with the invasive Red Imported Fire Ant
and the argentine ant
. Their decline has affected many native species, especially those for which the red harvester ant is a chief source of food, such as the Texas horned lizard
. Red harvester ants are often mistaken for fire ant
s, but are not related to any fire ant species, native or introduced. This class of ants is also known to have both male and female genesis.
Red harvester ant nests are characterized by a lack of foliage and small pebbles surrounding a hole that is usually at grade. Hollowed out seeds, however, are found scattered around the nest. In grassland
areas, like ranches, the lack of plant life makes red harvester ant colonies very easy to spot.
The mounds are typically flat and broad, 0 to 100 mm (0 to 3.9 in) high, and 300 to 1200 mm (11.8 to 47.2 in) in diameter
. There have been reports of even larger denuded areas, on the order of 10 m² (107.6 sq ft). Three to eight trails typically lead away from the mound, like "arms". These trails are used by ants to collect and bring food back to the mound. "Scout" ants are the first ones out of the mound every morning. They seek food, and mark their path as they return to the mound to alert the worker ants. The worker ants follow the scent trail and collect the food. Other ants, called "middens", spend their time cleaning and tending to the mound. All worker ants and middens are female.
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
common in the southwest
Southwestern United States
The Southwestern United States is a region defined in different ways by different sources. Broad definitions include nearly a quarter of the United States, including Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Texas and Utah...
United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Description
The main food source for red harvester ants usually consists of seeds, which they hoard in great numbers, hence their name.As with most ant species, their mating castes consist of winged alates (reproductives) that reside in the nest until weather permits them to fly away and mate. After that the male usually dies, while the now-fertilized queen returns to the ground to search for a suitable nesting site. Once she has chosen a site, she sheds her wings and begins to reproduce, creating a new colony. She produces "worker ants" for 1–20 years until her death.
Red Harvester Ants can be aggressive and have a painful sting
Schmidt Sting Pain Index
The Schmidt Sting Pain Index is a pain scale rating the relative pain caused by different Hymenopteran stings. It is mainly the work of Justin O. Schmidt, an entomologist at the Carl Hayden Bee Research Center in Arizona...
that spreads through the lymph node
Lymph node
A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
s, sometimes causing reactions, especially in animals allergic
Allergy
An Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...
to their venom
Venom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
. They can also bite ferociously.
Over the years, their numbers have been declining, and this has often been attributed to competition for food with the invasive Red Imported Fire Ant
Red imported fire ant
See main article Fire ant.The red imported fire ant , or simply RIFA, is one of over 280 species in the widespread genus Solenopsis...
and the argentine ant
Argentine ant
The Argentine ant, Linepithema humile, is a dark ant native to northern Argentina, Uruguay, Paraguay, and southern Brazil...
. Their decline has affected many native species, especially those for which the red harvester ant is a chief source of food, such as the Texas horned lizard
Texas horned lizard
The Texas horned lizard is one of about 14 North American species of spikey-bodied reptiles called horned lizards. P. cornutum ranges from Colorado and Kansas to northern Mexico , and from southeastern Arizona to Texas. There are also isolated, introduced populations in the Carolinas, Georgia, and...
. Red harvester ants are often mistaken for 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 :...
s, but are not related to any fire ant species, native or introduced. This class of ants is also known to have both male and female genesis.
Red harvester ant nests are characterized by a lack of foliage and small pebbles surrounding a hole that is usually at grade. Hollowed out seeds, however, are found scattered around the nest. In grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
areas, like ranches, the lack of plant life makes red harvester ant colonies very easy to spot.
The mounds are typically flat and broad, 0 to 100 mm (0 to 3.9 in) high, and 300 to 1200 mm (11.8 to 47.2 in) in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
. There have been reports of even larger denuded areas, on the order of 10 m² (107.6 sq ft). Three to eight trails typically lead away from the mound, like "arms". These trails are used by ants to collect and bring food back to the mound. "Scout" ants are the first ones out of the mound every morning. They seek food, and mark their path as they return to the mound to alert the worker ants. The worker ants follow the scent trail and collect the food. Other ants, called "middens", spend their time cleaning and tending to the mound. All worker ants and middens are female.
External links
- http://www.econtalk.org/archives/2007/08/gordon_on_ants.htmlEconTalk interview with Deborah GordonDeborah GordonDeborah M. Gordon is a biologist at Stanford University.- Major research :Gordon studies ant colony behavior and ecology, with a particular focus on red harvester ants. She focuses on the developing behavior of colonies, even as individual ants change functions within their own lifetimes.Gordon's...
and her research on Red harvester ants]