Authors as Published

T. Michael Likins, Agriculture and Natural Resources Environmental Horticulture, Chesterfield County, Virginia Cooperative Extension and Eric Day, Insect Identification Lab Manager, Department of Entomology, Virginia Tech


The Asian needle ant is a small, dark brown to black ant that has antennae tips and legs that are often lighter or orange-brown in color. The workers are typically 5 mm in length and a queen may be 6.5 mm in length.

Adult Asian Needle Ant
Fig 1. Adult asian needle ant

The ant is a native of China, Japan and the Koreas, and has been identified from several counties in Virginia in 2012. Anecdotal references indicate it may have arrived in the Commonwealth as early as the 1940s. Recent reports indicate thatthe ant is distributed in nine states fromConnecticut to Florida.

The Japanese name of oo-hari-ari, or giant needle ant refers to the sting and not the size. The venom delivered through the stinger can be a major allergen to people who are sensitive to insect stings.


The Asian needle ant is considered a leaf litter inhabitant and a general scavenger. In nature, the ants can be found in damp areas below stones or rotting logs. In residential settings, the ant can be found in mulch and under railroad ties, bricks and pavers. The ants have been reported to forage inside homes and may pose a problem in the future.


Researchers in other states have reported that the Asian needle ant supplants native ant species thereby upsetting the natural balance. Additional information also indicates that plant species dependent on native ant species to spread their seeds do not have the same relationship with the exotic ants. 

As a health risk, the ant’s venom can produce reactions ranging from mild irritation to lifethreatening anaphylaxis.

Asian needle ant stinger
Fig 2. Asian needle ant stinger


Avoid outdoor situations that can support the ant’s establishment, such as downed trees and mulch beds. Research is lacking on the efficacy of baits. If pesticides are necessary, refer the Pest Management Guide for outside ant control.


Pachycondyla species are not native to the United States. As an introduced species, it represents a threat to biodiversity and poses a health risk to individuals that may be sensitive to insect venom.

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Virginia Cooperative Extension is a partnership of Virginia Tech, Virginia State University, the U.S. Department of Agriculture, and local governments. Its programs and employment are open to all, regardless of age, color, disability, gender, gender identity, gender expression, national origin, political affiliation, race, religion, sexual orientation, genetic information, military status, or any other basis protected by law.

Publication Date

June 4, 2018

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