Red fire ant
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Red fire ant ( Solenopsis invicta ) |
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| Solenopsis invicta | ||||||||||||
| Buren , 1972 |
The red fire ant ( Solenopsis invicta ) is a representative of the fire ants ( Solenopsis ) originally from South America , which belong to the subfamily of the knot ants (Myrmicinae). Since around 1920 the red fire ant has spread as a neozoon in the southern states of the USA , more recently also in Australia , China and Taiwan .
Way of life
As with many species of ants, communication takes place primarily via odorous substances, so-called pheromones . The ants produce a number of these substances and thus communicate within their colony. In addition, there is tactile communication and noises that are generated by stridulation or knocking of the legs, but which are only audible to members of the same species within a radius of a few centimeters.
Fire ants survive floods by chaining the individual female animals and larvae with their bodies to form a raft . The rafts can only consist of female workers. Mostly they also accommodate brood and queens, often symbionts and male ants as well. However, it has also been observed that male ants were prevented from taking up space on the raft. Lone ants drown.
The red fire ant was the first ant species to be shown to have a magnetic sense . The antennae of the ants were discussed as a possible “seat” of the magnetic senses.
Spread and problems
Its rapid spread after its introduction in the USA is due to its aggressive behavior, which it shows both against other species of ants and against potential attackers such as humans. This behavior has earned it a rather unusual scientific species name: Solenopsis invicta translates as "The undefeated fire ant". However, not only humans suffer from the spread of insects. The fire ants are effective predators among insects. They feed on almost all other insects, making them one of the most effective weapons against pests in agriculture. Here it is partly used to reduce the populations of the corn borer (several species of small weevils), various aphids and a number of other harmful insects. However, the introduced red fire ants are particularly aggressive against other species of ants. In the southern United States, for example, they almost wiped out the fire ants, Solenopsis xyloni and Solenopsis geminata, which were once native here . The populations of the harvest ants Pogonomyrmex badius were also drastically reduced by the introduced species and many other ant species are also threatened by the red fire ant. In the southern United States, attempts at biological control by a natural enemy began a few years ago. A type of parasitoid humpback flies ( Phoridae ), Euryplatea nanaknihali , also called executioner flies , which were imported from Brazil, are used.
The females of this fly attack the much larger ants in a dive and inject an egg into their mesosomes . The larva slowly weakens the host animal until it dies and is laid down by other workers in front of the burrow. The young flies hatch here shortly afterwards. These begin the next wave of attacks in a very short time. Although the effectiveness as a parasitic enemy is low (estimates: <3% infestation), the flies can seriously disrupt normal nest building, food procurement and brood care if they occur in large numbers.
In China, authorities began fighting colonies in Hong Kong and Guangdong in early 2005 . The red fire ant has also spread to Australia.
Attack and effect on humans
In some states of the USA the red fire ant has developed into one of the most common allergy triggers. In the affected areas such as Texas , around 13 percent of the population are victims of ant attacks every year - more than in the same period, for example, from the notorious “ killer bees ” or wasps .
When attacked, the little ant attacks the abdomen with a combination of its jaws and poison sting. First she bites into the skin and injects her poison into the wound. Several of these attacks occur at short intervals. The poison consists mainly of highly effective alkaloids , which cause a burning skin reaction with a slight delay. The affected area becomes fire red and forms pustules , and shock reactions occur in allergy sufferers . These are triggered by various components of the poison, of which only four have been identified so far.
Encounters with individual ants are therefore only dangerous for allergy sufferers. However, if a colony of the animals is disturbed, several hundred groups rush to the potential attacker. Serious "burns" and life-threatening shock reactions are the result of such an encounter.
literature
- Bernhard Kegel : The ant as a tramp. From biological invasions . 3. Edition. Ammann Verlag & Co. Zurich 2000. ISBN 3-250-10404-3
Web links
- Risk of infection from exotic ants
- Film / Video: The Conquerors (1/4), (1): The Fire Ant, Arte F, France 2013, 43 minutes
Individual evidence
- ↑ Fire ants hug each other in a lifeboat , Spiegel Online , April 26, 2011.
- ^ Ernesto I. Badano: Species richness and structure of ant communities in a dynamic archipelago: effects of island area and age. In: J. of Biogeography , Volume 32, No. 2, 2005, pp. 221-227. doi : 10.1111 / j.1365-2699.2004.01174.x
- ^ A b C. Anderson, G. Theraulaz, J.-L. Deneubourg: Self-assemblages in insect societies. In: Insectes Sociaux , Vol. 49, No. 2, May 2002, pp. 99-110.
- ↑ a b c Benjamin J. Adams, Linda M. Hooper-Bùi, Rachel M. Strecker, Daniel M. O'Brien: Raft formation by the red imported fire ant, Solenopsis invicta. In: J Insect Sci. Volume 11, 2011, p. 171 doi : 10.1673 / 031.011.17101 .
- ↑ JB Anderson and RK Vander Meer: Magnetic orientation in the fire ant, Solenopsis invicta. In: Natural Sciences. Volume 80, No. 12, 1993, pp. 568-570, doi: 10.1007 / BF01149274 .
- ↑ Jandira Ferreira de Oliveira et al .: Ant antennae: are they sites for magnetoreception? In: Journal of the Royal Society Interface. Volume 7, No. 2, 2010, pp. 143-152, doi: 10.1098 / rsif.2009.0102 .
- ↑ Fire Ants 3D (documentary, German, about ants, nature documentary, animal documentary), accessed on September 22, 2019
- ↑ The executioner fly beheads ants, in: Augsburger Allgemeine - Wissenschaft , July 3, 2012, accessed on September 22, 2019
- ↑ Documentation 'Invasion of the Fire Ants', USA 2006, director: Jeff Morales, 43min. Very good macro photos of the Phoridae flies. First broadcast on ZDF 2006, arte October 15, 2008.
- ↑ Lloyd W. Morrison, Biological Control: Guide to natural enemies , SW Missouri State University. English, accessed October 17, 2008.
- ^ Urgent action taken against fire ants.
- ↑ Michael T. Henshaw, Nicole Kunzmann, Cas Vanderwoude, Matthias Sanetra, Ross H Crozier: Population genetics and history of the introduced fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), in Australia. In: Australian Journal of Entomology 44, No. 1, 2005, pp. 37-44, doi: 10.1111 / j.1440-6055.2005.00421.x .