Allegheny mound ant

Allegheny mound ant is a large, bicolored, mound-building ant. It is found in the United States from Maine to Georgia, west to Colorado and New Mexico, and in adjacent Canadian Provinces. Within that range, it occurs only sporadically in the south, in the west, and in Canada. It is most common from New England to Illinois. It is uncommon in Minnesota.

Workers are ⅛″ to 5 ⁄16″ (4.5 to 7.5 mm) long, black, and somewhat shiny. Winged males and queens are about the same size, 5 ⁄16″ to ⅜″ (8 to 9 mm) long. The body is divided into four easily distinguishable sections: the head; the first body section behind the head (mesosoma); the narrow, waist-like section (petiole); and the inflated rear section (gaster). The head and mesosoma are yellowish-red, light red, or medium red. The gaster is dark. The body is virtually hairless. Only the back of the gaster has erect hairs.

The head is red and broadly rounded in outline. The rear margin is distinctly concave, an important distinguishing feature of this species. There are two large compound eyes on the sides of the head and three simple eyes (ocelli) in a triangle on the top of the head. The jaws (mandibles) have at least seven teeth. On the worker, the antennae have twelve segments, on the male they have thirteen. There is a hardened plate (clypeus) on the face above the mandibles. The clypeus is not notched or concave on its outer (anterior) margin. The antennae are inserted on the face well above the clypeus.

The mesosoma is lumpy, not smoothly convex. It is covered with three exoskeletal plates, each forming a distinct bump. The first plate (pronotum) and second plate (mesonotum) cover the thorax. Together they are referred to as the promesonotum. The third plate (propodeum) covers the first segment of the abdomen which is fused to the thorax. When viewed from the side, the propodeum is distinctly lower than the level of the promesonotum. The petiole has a single raised bump (node). The gaster is bulbous and very dark brown, looking almost – but not – black. At the end of the gaster there is a tiny but distinctive nozzle (acidopore). The acidopore is fringed with hairs.

Worker: ⅛″ to 5 ⁄16″ (4.5 to 7.5 mm)

Male: 5 ⁄16″ to ⅜″ (8 to 9 mm)

Queen: 5 ⁄16″ to ⅜″ (8 to 9 mm)

Ulke’s ant (Formica ulkei) head is dark on top, red below. The mesosoma is red, the gaster black. There are many erect hairs on the body.

Open shrublands and woodlands, woodland edges and openings

Workers are aggressive and will bite if their mound is disturbed. Using their acidopore, they inject formic acid into small trees and shrubs near their colony, killing those plants.

They invade the nests of, and enslave, colonies of somewhat silky mound ant (Formica subsericea) and other ants in the fusca group of Formica ants.

Allegheny mound ants build very large dome-shaped mounds (nests) that can be up to one meter high and two meters in diameter. The mounds are covered in soil, not thatch. They are often clustered. Adjacent mounds are often interconnected and they share foraging trails. Each mound can have up to twelve queens.

Plant sap and flower nectar

Mostly honeydew of aphids, scale insects, and tree hoppers, but they also prey on various insects.

Sources

7, 24, 27, 29, 30, 80, 82, 83.

Common in the east, uncommon in Minnesota.

some type of ant

large ant mound (12" across, 4-6" tall) one of two seen in southeast corner of the prairie. Similar to the allegheny mound ant from what I can see on the website.

Ant Colony.....

Not sure what kind of ants they are but they were in a thick clump along the area I was walking. I do not think I have ever seen this kind of ant. Maybe fire ants or some other kind I haven’t seen around the yard or in town.

I think they were carrying some larvae around. I did film them too. They did not come near me they just seemed so busy doing whatever they were doing. I often looked down to be sure none were crawling on me though I did remain 3-5 feet away. It was chilly out so I think maybe they didn’t notice me and had to get whatever they were doing done. I have never seen so many ants in a small area crawling on top each other etc. Sending a large resolution since they are small and maybe that will help identify them better or maybe you will know what they are doing.

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allegheny mound ant foraging trail
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Location: Kasota Prairie in LeSueur County

large ant mound (12" across, 4-6" tall) one of two seen in southeast corner of the prairie. Similar to the allegheny mound ant from what I can see on the website.

Location: Lee WPA, rural Norman Co. MN

Not sure what kind of ants they are but they were in a thick clump along the area I was walking. I do not think I have ever seen this kind of ant. Maybe fire ants or some other kind I haven’t seen around the yard or in town. I think they were carrying some larvae around. I did film them too. They did not come near me they just seemed so busy doing whatever they were doing. I often looked down to be sure none were crawling on me though I did remain 3-5 feet away. It was chilly out so I think maybe they didn’t notice me and had to get whatever they were doing done. I have never seen so many ants in a small area crawling on top each other etc. Sending a large resolution since they are small and maybe that will help identify them better or maybe you will know what they are doing.