How to control red imported fire ants biologically?

Invasive red imported fire ant is one of the most terrible invasive ants in the world, which has spread to many places in North America, Asia and Australia. With its amazing competitiveness and adaptability, it can quickly establish a strong ecological advantage wherever it goes, crowding out and replacing local ants and arthropods, and finally causing a serious decline in the biodiversity of local ecosystems.

Faced with this grim situation, many ant experts are studying the competitive relationship between local ants and red imported fire ants. They hope to find some local ant species that can compete with red imported fire ants, so as to optimize the control strategy of red imported fire ants and curb the spread of red imported fire ants.

Fire ant

18 results of the confrontation between ants and red imported fire ants

Zoology has read many papers about the interspecific confrontation of ants, and found that red imported fire ants can easily defeat other ants even if the number is the same. So, which ants can beat the red imported fire ants in number? What will happen if red imported fire ants meet army ants? On these issues, we will start with Florida in the southeastern United States today.

Florida is one of the areas invaded by red imported fire ants. In order to explore the resistance of local ants to red imported fire ants, scholars studied the resistance relationship between red imported fire ants and 18 local common ant species. The specific experiment is: put a certain number of imported red fire ants and another ant into two plastic plates, and then connect them with a plastic plate in the middle with a rubber hose. Turn on the hose switch, and both ants can enter the central plate, which is the main battlefield of ants.

After a period of time, scholars need to count the number of deaths on both sides. The statistics of dead individuals are very important for the whole study, because the ratio of the number of deaths between two parties (local ants in front and red imported fire ants in the back) can be quantified as the antagonism index between species. When the antagonistic index is greater than 1, it shows that the ant species has relatively weak fighting capacity against red imported fire ants, and when the antagonistic index is less than 1, it shows that the ant species has better antagonistic ability. This concept is easy to understand, just like the exchange ratio or battle damage ratio often mentioned in human wars. Let's take a look at this 18 ant's antagonism index.

If we look at this table, we can see that 18 species of local ants, 13 species are obviously no match for red imported fire ants, and the other five species have significantly less deaths in the battle than red imported fire ants, indicating that they really have extraordinary fighting power. Among the ants whose battle damage ratio is higher than 1, fast ants and tropical fire ants play better, and the battle damage ratio is slightly higher than 2. The death number of red-backed ants and red-headed ants is about four to five times that of red imported fire ants, and the exchange ratio of several ants is close to ten times or even ten or twenty times. We can easily imagine that it must be a scene of collapse and rout.

This army ant was beaten out of the water by red imported fire ants.

Among these adversaries whose antagonism index is higher than 1, it is worth noting that there is a military ant-Nevus, which comes from the genus Nevus and contains 129 species, which is the largest and most widely distributed among the military ants in the New World. Black-breasted tile ants are distributed in the southern United States and Central America. Worker ants are 2.2 to 4.6 mm in length, and there are tens of thousands of worker ants in the community as their external combat forces, mainly feeding on other ants and beetles.

Ants in the dark

However, in the confrontation test, tile ants with dark breasts did not perform well, with a total of 475 workers killed, but only 77 workers lost to red imported fire ants, with an exchange ratio as high as 6.2: 1.

In the wild, the number of worker ants in Tilia fusca community is not as much as that of red imported fire ants, and the fighting capacity is obviously not as good as that of the same number of red imported fire ants, so this army ant can hardly be used as a biological factor to inhibit the mature community of red imported fire ants.

Nevertheless, we can never say that any kind of army ant can't defeat the invading red imported fire ant, because the army ant subfamily contains 26 genera and as many as 8 13 species. At least in the new world, the strength of ants is likely to be higher than that of imported red fire ants.

Ants in the dark carry eggs.

In addition, the interspecific relationship of ants is also restrained. For example, another invasive ant, the fire ant, has expanded rapidly and caused serious harm, and there is another member of Neva platyphylla who preys on it in its place of origin. Flat tile ants hardly need to fight when attacking the nest of small fire ants. Just releasing pheromones can make small fire ants panic and leave their nests. On weekdays, the majestic little fire ants can be said to be restrained and have no temper. Therefore, it is difficult to say whether there is special concern about the existence of red alien fire ants among the military ants who are rarely studied and lack ecological information.

The big-toothed ant challenged twice as many imported red fire ants and won a great victory.

Speaking of the best local ants, they belong to the subfamily Macrophyllae. When faced with twice the number of red imported fire ants, it lost 107 in the battle, but it cost the red imported fire ants a heavy price of 562 workers. The battle loss ratio was close to 1 5, which was beyond the reach of other 17 ants.

Big-toothed ant

The reason why it is so powerful is its huge size. The average body length of worker ants is 8 mm, in contrast, the average body length of worker ants of red imported fire ants at all levels is 3.84 mm, and only large worker ants can exceed 5 mm. More importantly, the disproportionately large jaws of big toothed ants can reach incredible super-high speed when attacking. It has been pointed out that another member of the genus Macrosaurus, Macrosaurus baumannii, can close its jaw at a speed of 64.3 meters per second, which is about 23 1.5 km/h (this biting speed has been the highest in the animal kingdom for more than ten years, and it was not until last year that Camilla's speed of 324 km/h was broken), and the impact force generated at such a high speed is 37/kloc.

Big-toothed ant

This has also been proved in the battle. Brown-toothed ants can fly red imported fire ants 35 cm away with their jaws. But interestingly, although the red imported fire ants were completely defeated by the red imported fire ants, it was observed that when they met the red imported fire ants, the red imported fire ants would always retreat in a hurry because of the pungent smell released by the latter. Let's look at the poor performance of red imported fire ants-65,438+00 red imported fire ants can replace 1 red imported fire ants, and we can find that there is a circular restraint.

Although the fighting capacity of red-toothed ants is superb, the number of their communities is generally only tens to hundreds, and they are helpless in the face of thousands of mature red imported fire ants, but it is likely that a small group of red imported fire ants are used.

Three species of disk-bellied ants defeated red imported fire ants with chemical weapons.

Three species of Panbelli, namely, Panbelli Harmo, Panbelli Texas and Panbelli Tennessee, performed well in the conflict with red imported fire ants, and the exchange ratio was one to two or even one to three. What is the secret of their success? In terms of size, members of Pampeli are generally not small. The worker ants of Panbelli alzheimer are large, usually 7 to 8 mm long. The workers in Pemberley, Texas are more than 5.5 mm long, and those in Tennessee are 6 to 6.6 mm long. More importantly, the chemical weapons of ants are very powerful. When dealing with red imported fire ants, their killing method is to sting red imported fire ants with pincers at the end of abdomen and inject venom, which can obviously kill red imported fire ants. The worker ants of the red imported fire ant will die as long as they are stung by the pliers of the red imported fire ant for the second time. If you are stung only once, paralysis 10 can be recovered in 20 minutes.

Although powerful, there are not many worker ants in the ant colony. There are only a few hundred worker ants in Texas and Alejandro, and hundreds to thousands in Tennessee. Therefore, we can hardly expect them to compete with mature red imported fire ants. However, it should be feasible to clean up newly married or small communities of red imported fire ants. After all, ants in Florida have been observed attacking newly-married imported red fire ants.

Pan-abdominal ant

Those ants whose resistance index is less than 1 often occupy different habitats from red imported fire ants. For example, although Pan-bellied ants in North America are distributed in all habitats, they especially like forest ecosystems, while red imported fire ants don't like woodland very much, which may be balanced through long-term interaction and replacement. In view of this situation, in order to control the red imported fire ants, some scholars put forward a scheme, that is, artificially designing an animal community and introducing strong ant species into the invasion area as its competitors, such as the more powerful ant species in this paper. Of course, this method can be very dangerous. It is necessary to ensure that the introduced species will not cause ecological disasters like red imported fire ants. In the future, it is necessary to conduct strict behavioral, ecological and systematic research on these ants.

Although some species of ants can beat the red imported fire ants in a fair competition, their natural communities are too small and they live in different habitats from the red imported fire ants, so it is difficult to control the red imported fire ants in the wild. It seems that red imported fire ants can invade several continents, and it's really terrible to flood to this extent.

There is another ant in the list called New Black Haired Ant, which can also defeat imported red fire ants. I have also talked about it in other articles.