Myrmecia inquilina facts for kids
Quick facts for kids Myrmecia inquilina |
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| Conservation status | |
| Scientific classification | |
| Genus: |
Myrmecia (ant)
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| Species: |
inquilina
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The Myrmecia inquilina is a special type of ant found only in Australia. It belongs to a group of ants called Myrmeciinae. Scientists first found this ant in 1955. It was officially described in 1959 by Athol Douglas and William Brown Jr.
These ants are quite large, growing to about 21.4 millimeters (0.84 inches) long. When it was discovered, M. inquilina was the first known social parasite among these older, more basic ant groups. A social parasite means it lives in another species' nest and relies on them. Today, it's one of only two Myrmecia species that don't have worker ants.
M. inquilina lives in the nests of two other ant species: Myrmecia nigriceps and Myrmecia vindex. Interestingly, these ants don't fight with their host species. Sometimes, a host colony will only produce M. inquilina young, months after the parasite queens start laying eggs. The M. inquilina queens might eat the host colony's young or special "trophic eggs" (eggs laid for food). Other Myrmecia species might kill M. inquilina queens if they try to join their nests.
Because it lives in a small area and its home is threatened, the M. inquilina ant is listed as "vulnerable" by the IUCN Red List. This means it's at risk of becoming endangered.
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Ant Discovery and Naming
Before M. inquilina was found, scientists thought that parasitic ants only existed in more advanced ant groups. They believed older ant groups lacked certain features for parasitism. But the discovery of M. inquilina changed this idea. It suggested that parasitic ants might also exist in other primitive groups.
William Brown collected the first M. inquilina ants in 1955. He found them in large fallen trees in Western Australia. In 1956, it was announced as the first parasitic ant in the primitive ant subfamilies. Athol Douglas and William Brown Jr. officially described the ant in 1959. They published their findings in a science journal.
The ant's specific name, inquilina, comes from the Latin word inquilinus. This word means "tenant." It refers to how the ant lives inside another colony as a "guest" or "renter." This name perfectly describes its parasitic lifestyle.
The first female specimen, called the holotype, was found in a M. vindex nest. This happened on March 23, 1955, near Wagin in Western Australia. This important specimen is now kept at the Western Australian Museum in Perth.
What Does This Ant Look Like?
Myrmecia inquilina is a large ant, but it's still smaller than the ants it lives with. Its body is about 21.4 millimeters (0.84 inches) long. Its head, including the clypeus (a plate on the front of the head), is about 2.9 millimeters (0.11 inches). The antennae are 3.5 millimeters (0.14 inches) long. Its eyes are about 1.25 millimeters (0.05 inches) wide.
The ant's mandibles (jaws) are thin and have four to five sharp teeth. Its antennae look similar to those of M. vindex, but they are smaller. The petiole (a narrow waist segment) is also longer and wider. The postpetiole (the segment after the petiole) is triangular and narrower than those of M. vindex queens.
The clypeus, legs, and antennae have many tiny spots. The postpetiole and gaster (the main body part at the back) have fewer spots. M. inquilina is special because it doesn't have many long, soft hairs. Only small, upright hairs are found on its mandibles and the tip of its gaster. Short hairs can be seen on its legs, back, and thorax (middle body section).
This ant has fine, short, greyish hair called pubescence. This hair is shorter and more noticeable on its clypeus and legs. It is also clear on the postpetiole and gaster.
The head and gaster of M. inquilina are black. The clypeus and areas around the frontal carinae (ridges on the head) are reddish-brown. The mesosoma (middle body), node (part of the waist), and legs are light brownish-red. The legs become yellowish in some spots. The antennae and mandibles are brownish-yellow, and the teeth have black edges.
You can tell M. inquilina apart from other ants by its black head and its almost hairless body. Its color is similar to M. nigriceps. However, M. nigriceps is larger and covered in hair. Also, its head is more rounded. M. inquilina is unique because it does not have a worker caste. This means it is a workerless parasite.
Where Does This Ant Live?
Myrmecia inquilina is found only in the southwest part of Western Australia. The first specimen was collected about 225 kilometers (140 miles) from Perth.
These ants live in colonies with M. vindex and M. nigriceps. They are found in the soil, under logs, and under flat rocks in wooded areas. They often live in places with granite rocks and trees. Some of the trees found in their habitat include Corymbia calophylla, Acacia acuminata, and a large type of Allocasuarina tree.
The place where the first specimen was found was mostly cleared for farming. However, some wooded areas with many large fallen trees remained. M. inquilina ants are usually found deep inside the host nests. They can be as deep as 25 centimeters (10 inches) and are often near the host queen.
Ant Behavior and Life Cycle
Myrmecia inquilina is one of only two Myrmecia species that do not have worker ants. It is an inquiline species, meaning it lives in the nests of M. nigriceps and M. vindex colonies.
This ant is a polygynous species. This means that a single colony can have many queens, sometimes from two to several dozen. Some of these M. inquilina females are "ergatoid" ants. This means they lose their wings after they grow up inside their cocoons.
The parasitic queens can live in the host nest for a long time. However, M. inquilina queens will eventually replace all the host's young with their own eggs. This happens several months after they enter the nest. This occurs if the M. inquilina queens eat or destroy the host's young. The host workers will even care for the parasite's young and protect them.
M. inquilina queens often nest close to the host queen and her young. Host worker ants attend to them without any fighting. Scientists think that the parasitic queens eat special "trophic eggs" laid by the workers. These are eggs laid as food, not for hatching.
Other Myrmecia species can be a danger to M. inquilina. For example, if an M. inquilina queen meets M. regularis workers, they will immediately grab and kill her.
Flying is important for this species, even though it lives in a small area. Queens never leave the nest to search for food. They only leave if they are in great need. Fully grown female ants appear during the summer, before their nuptial flight (mating flight).
Between 9 and 10 PM in January, queens and males come out of their host nests to mate. Observations show that the winged ants will climb onto objects like lighted lamps. After about half an hour of running around, they start to fly. When queens are looking for a new host nest, M. vindex ants might find a queen and take her. This suggests that workers actively bring fertilized queens to their nests. Host colonies with M. inquilina queens tend to be smaller and weaker than colonies without them. However, these host colonies can still produce their own winged offspring.
Conservation Status
Myrmecia inquilina is the only species in its group listed as "vulnerable" by the IUCN Red List. This status needs to be checked and updated.
Losing their natural home is a big reason why this ant might be at risk. Scientists Douglas and Brown noted that a chemical spray, dieldrin, used to control argentine ants, destroyed many nests where M. inquilina lived. Also, controlled burn-offs (fires set on purpose) are a threat to colonies that house M. inquilina.
