Worker:

 

Worker with termite:

 

Young queen:

 

Male:

 

 



Pachycondyla chinensis, the Asian Needle Ant

 

                People living in the southern part of the USA have heard and probably experienced the fire ants (Solenopsis invicta) and the Argentine ants (Linepithema humile). Those two ants cause serious economical, medical and ecological problems. Unfortunately a new invasive ant is spreading and people will have to learn how to recognize and handle it. Its scientific name is Pachycondyla chinensis, also called the Asian needle ant.

 

How to recognize it?

                The Asian needle ant, Pachycondyla chinensis, is an insect, which means that it possesses 6 legs and 2 antennas. Like all ants, the giant needle ant will be find living in colony, usually those ones are composed of 400 individuals, but however, some can be much smaller (a few dozen of individuals) or much bigger (several thousands).  
                But there over 170 species of ants in North Carolina, and all have their own characteristics that allow entomologists to recognize them. So how to identify Pachycondyla chinensis easily?
                Of course, the general appearance can help, but the way to describe it is small, black and skinny. The problem is that at least 30 species fit this description, so this is not really useful. However, there is one trick that can help to recognize it very easily. As you probably know, ants have the incredible faculty to go everywhere and especially to defy gravity. If as a kid, you have tried to catch ants and then put them in a jar, you have quickly noticed that climbing glass was not an issue for them. This is true for most ants in North Carolina, except… the Asian needle ant, Pachycondyla chinensis. This ant is a very bad climber and the walls of the jar are insurmountable obstacles for it. Realizing this experience is probably the simple way to recognize the Asian needle ant.

This is how to do it properly. Firstly, when you collect the ants, be careful, because those sting and this is VERY painful! Place them into a container with vertical border and with a relatively slick surface, like a glass, a clean jam jar (the container must be clean), or a plastic box. Then put the container on a flat surface, like a table, and then look! If you can observe that the ants are struggling and finally failed to climb, there is a good chance that it is Pachycondyla chinensis. If the ants can climb and leave the container, so let them in peace, it is not Pachycondyla chinensis.
However, here is a more precise description and some pictures to help you to recognize it and don’t put all the ants you will meet in jars. The ants measure about 6 mm (0.2 inch), they are dark black with the tip of the body (where the sting is) which can be reddish-brown (but not always). The ant has a long and skinny body on which you can easily distinguish the head, the thorax, the node (one petiole in the middle) and the abdomen. If you are not sure, take a look to the following pictures (see the end of this page too).

Asian needle ant

 

Notice the reddish-brown tip of the abdomen on this worker.

Pachycondyla chinensis
 

Once you think you got some, please contact us (zeroben (at) gmail.com) to update our database and verify their presence.

 

A little bit of history.


                In 1934, the entomologist Marion Smith reported the presence of a species of ant native from Asia, Pachycondyla chinensis. The species was found two years earlier in several coastal localities of Georgia, North Carolina and Virginia. The distribution of 1934, let supposed that the ants were already introduced for a few years in North America. Pachycondyla chinensis was then described as having small nest size of a few hundred workers. Later on, in 1951, Smith described it has a species which does not have any economic importance. So, no interest was given to this new exotic from the scientific community or from the public, contrary to the famous Argentine ants and Fire ants that quickly reveals themselves as real pests.
                The story could stop here. However, in summer 2006, we discovered populations of Pachycondyla chinensis in different forests around Raleigh.  Quickly, we realized that the presence of P. chinensis seemed to be linked with the absence of other common native ants. While most invasive species of ants, like Fire ants or Argentine ants, are found in areas disturbed by human activities, most of them can not establish their nest in undisturbed areas. For this reason, those areas could provide refuges for native fauna. Unfortunately, the populations of Pachycondyla chinensis were found in forests that did not seemed to have been affected by human activities for decades, like National or State Parks.
The refuges could be in danger?
                The results of our study have shown that most species of native ants were not found in areas colonized by P. chinensis. This could be problematic for native ant species. But the problem does not stop here. Ants (native ones) play fundamental roles in the equilibrium of ecosystems by their predator role, soil fertilizer but also in their association with some plants, like Ginger or Trillium, which seeds are dispersed by ants. Pachycondyla chinensis does not play those roles, and by affecting native ants, it is much more species that are also affected indirectly.


Human health.

                One other risk concerns human health. This ant has a stinger and knows how to use it if necessary. Contrary to Fire ants, Pachycondyla chinensis is not an aggressive ant and will try to flee if disturbed (when Fire ants tried to attack). However, if an ant is stuck between your skin and your clothes, or between your fingers and the piece of wood you are carrying, the ant will probably sting you. In that case, be cautious of how you can feel. Some people can react with strong allergenic reactions, like an anaphylactic shock. If you know you are sensitive to bee or wasp venom, be especially cautious.

 

Where to find P. chinensis?

                Until now, Pachycondyla chinensis was found in 9 states of the East coast: Alabama, Florida, Georgia, North Carolina, South Carolina, Tennessee, Virginia and it seems that an other population is establish in the states of Connecticut and New York (including Manhattan). The records from Alabama and Florida are from the 40’s and no recent records have been reports. However, in all the other states, populations are established and seem to expand. We try to monitor their distribution, so don’t hesitate to contact us (zeroben (at) gmail.com) if you think you found this ant.
                Pachycondyla chinensis lives in forests, but also in open habitat. In fact only one tree or a few trees, or just some wood on the ground are enough for them to nest. From our surveys, we found P. chinensis to be present in urban environment at many occasions, like in the backyard of houses or on the campus of University.
The nest are found essentially into or under logs, twigs and any other piece of rotten wood on the ground, and also more rarely under rocks and in the ground. The colony can be composed of a few dozen of worker to several thousands. If you find them be cautious if you manipulate them!

                If you have any questions, don’t hesitate to contact me. 

 

Do not confuse the Asian needle ant with other species

Recognize Pachycondyla chinensis, the asian needle ant, from other ants is not easy for most people. Here are some of the most common ants found in North Carolina (and elsewhere) that P. chinensis is confused with. Take a look (click on the icons) and notice the differences:

 

The carpenter ants

much bigger

(about 0.4 inch)

The Formica species

bigger

(about 0.3 inch)

The odorous ant

smaller and brown

(about 0.15 inch)

The Aphaenogaster

same size but redish

(about 0.2 inch)

The fire ants

red and black

(about 0.2 inch)

More pictures of this species here

More pictures of this species here

More pictures of this species here

More pictures of this species here

More pictures of this species here

 

Pachycondyla chinensis, the Asian needle ant