I’m referring to the Acanthinus argentinus, which is an ant-like flower beetle in the subfamily Anthicinae of the family Anthicidae. Over the last couple of months, I've been fortunate enough to be able to observe this species at my residence. Every time that I notice this species I get very excited and immediately have to take pictures of them. I've included some of my observations of them below. What I've noticed about this species is that they run very fast, so it can be difficult to get great pictures of them sometimes. This species could easily be mistaken for the little black ant, Monomorium minimum, as they are approximately the same size, but the abdominal area is larger than that of M. minimum. Their movement is somewhat different and faster than M. minimum, so that is also a good indication that you're not looking at an ant, but that of A. argentinus or perhaps another Acanthinus species. Based on my observation of this species, they are nocturnal and are attracted to lights, even the light emitted from laptops. I’ve also noticed that they don’t usually travel alone, and sometimes there will be a quite a number of them exploring an area at a time. If you see one, there are sure to be more in another area not too far away.

A. Argentinus is a species native to the following South American countries: Argentina, Brazil, and Paraguay (Gimmel 2010). It is unknown exactly how the species made its way into the U.S.; however, it is theorized that this species may have gotten here through the major ports of Louisiana waterways via its “major shipping route,” the Gulf Intracoastal Waterway (Gimmel 2010). This species was first recorded in Louisiana in 2009; however, Florida was the first in the U.S. to record this species back in 2003 (Gimmel 2010).

The beetles of the Acanthinus genus are very tiny, and the U.S. species range in size from 2.0-3.2 mm (BugGuide 2012). If noticed, most people wouldn’t even realize they're actually looking at a beetle. If you are aware of these species, you may know that you’re looking at one of them, but being that these species are so small, taking a picture of it is the best way to differentiate a little black ant from an Acanthinus species.

There are seven species of Acanthinus in the United States, and they have a primarily southeastern distribution in the U.S. (BugGuide 2012).
1) A. argentinus—Texas to Florida to South Carolina
2) A. clavicornis—Louisiana and Texas
3) A. dromedaries—Texas
4) A. exilis—North Carolina to Tennessee to Florida to Louisiana
5) A. myrmecops—Maryland to Florida to Nebraska to Texas
6) A. scitulus—South Carolina to Florida to Texas
7) A. spinicollis—Southern Texas

For those of you who live in the U.S. and Canada and are outside the distribution range for these species, you may be interested to learn about other species in the subfamily Anthicinae. It’s definitely worth it to check them out if you have the time. https://bugguide.net/node/view/335097

If you’re ever sitting outside in the late evening hours, and see what looks to be a very tiny ant with a bigger than normal abdomen, take a picture of it. You may end up being surprised by what it is that you find. So bring your camera outside with you in the evening hours and see if you can help us add some observations of the Acanthinus species, or any Anthicinae species. Let’s get some more observations of these guys out there. They’re very interesting!

Gimmel, Matthew L. (2010) Acanthinus Argentinus (Pic) Newly Established in the Southeastern United States (Coleoptera: Anthicidae). The Coleopterists Bulletin 64: 94-95. http://lsuinsects.org/resources/docs/publications/Gimmel_2010_Acanthinus.pdf

BugGuide: Genus Acanthinus. 29 September, 2018. Phillip Harpootlian. 22 May, 2012. https://bugguide.net/node/view/61254

Posted on Ιούνιος 11, 2022 1035 ΠΜ by feistyone