Temporal range: Eocene – Recent
|Weaver ant (Oecophylla smaragdina) major worker (India).|
|Weaver ant (Oecophylla longinoda) major worker (Tanzania)|
|Formica virescens (junior synonym of Oecophylla smaragdina)|
|2 extant species|
13 extinct species
|Oecophylla range map.|
Oecophylla longinoda in blue, Oecophylla smaragdina in red.
Weaver ants or green ants (
Weaver ants vary in color from reddish to yellowish brown dependent on the species. Oecophylla smaragdina found in Australia often have bright green gasters. Weaver ants are highly territorial and workers aggressively defend their territories against intruders. Because they prey on insects harmful to their host trees, weaver ants are sometime used by indigenous farmers, particularly in southeast Asia, as natural biocontrol agents against agricultural pests. Although weaver ants lack a functional sting they can inflict painful bites and often spray formic acid directly at the bite wound resulting in intense discomfort.
- †Oecophylla atavina Cockerell, 1915
- †Oecophylla bartoniana Cockerell, 1920
- †Oecophylla brischkei Mayr, 1868
- †Oecophylla crassinoda Wheeler, 1922
- †Oecophylla eckfeldiana Dlussky, Wappler & Wedmann, 2008
- †Oecophylla grandimandibula Riou, 1999
- †Oecophylla leakeyi Wilson & Taylor, 1964
- †Oecophylla longiceps Dlussky, Wappler & Wedmann, 2008
- †Oecophylla megarche Cockerell, 1915
- †Oecophylla obesa (Heer, 1849)
- †Oecophylla praeclara Förster, 1891
- †Oecophylla sicula Emery, 1891
- †Oecophylla superba Théobald, 1937
The weaver ants belong to the ant genus Oecophylla (subfamily Formicinae) which contains two closely related living species: O. longinoda and O. smaragdina.
The common features of the genus include an elongated first funicular segment, presence of propodeal lobes, helcium at midheight of abdominal segment 3 and gaster capable of reflexion over the mesosoma. Males have
Oecophylla have 12-segmented antennae, a feature shared with some other ant genera. The mandibles each have 10 or more teeth, and the fourth tooth from the tip is longer than the third and fifth teeth. The palps are short, with the maxillary palps being 5-segmented and the labial palps being 4-segmented. The mesonotum is constricted and (in dorsal view) narrower than the pronotum and propodeum. The node of the petiole is low and rounded.
Distribution and habitat
O. longinoda is distributed in the
Weaver ant colonies are founded by one or more mated females (
Nest building behaviour
Oecophylla weaver ants are known for their cooperative behaviour used in nest construction. Possibly the first description of weaver ant's nest building behaviour was made by the English naturalist
The ants...one green as a leaf, and living upon trees, where it built a nest, in size between that of a man's head and his fist, by bending the leaves together, and gluing them with whitish paperish substances which held them firmly together. In doing this their management was most curious: they bend down four leaves broader than a man's hand, and place them in such a direction as they choose. This requires a much larger force than these animals seem capable of; many thousands indeed are employed in the joint work. I have seen as many as could stand by one another, holding down such a leaf, each drawing down with all his might, while others within were employed to fasten the glue. How they had bent it down I had not the opportunity of seeing, but it was held down by main strength, I easily proved by disturbing a part of them, on which the leaf bursting from the rest, returned to its natural situation, and I had an opportunity of trying with my finger the strength of these little animals must have used to get it down.
The weaver ant's ability to build capacious nests from living leaves has undeniably contributed to their ecological success. The first phase in nest construction involves workers surveying potential nesting leaves by pulling on the edges with their mandibles. When a few ants have successfully bent a leaf onto itself or drawn its edge toward another, other workers nearby join the effort. The
Relationship with humans
Large colonies of Oecophylla weaver ants consume significant amounts of food, and workers continuously kill a variety of
Weaver ant husbandry is often practiced in Southeast Asia, where farmers provide shelter, food and construct ropes between trees populated with weaver ants in order to protect their colonies from potential competitors.
Oecophylla colonies may not be entirely beneficial to the host plants. Studies indicate that the presence of Oecophylla colonies may also have negative effects on the performance of host plants by reducing fruit removal by mammals and birds and therefore reducing seed dispersal and by lowering the flower-visiting rate of flying insects including pollinators. Weaver ants also have an adverse effect on tree productivity by protecting sap feeding insects such as scale insects and leafhoppers from which they collect honeydew. By protecting these insects from predators they increase their population and increase the damage they cause to trees.
As food, feed and medicine
Weaver ants are one of the most valued types of
The larvae of weaver ants are also collected commercially as an expensive feed for insect-eating birds in Indonesia.
- Polyrhachis, other ants that weave nests (though less complex)
- Where the Green Ants Dream, a 1984 film directed by Werner Herzog
- Myrmarachne plataleoides, a spider that mimics the weaver ant
- Nanfang Caomu Zhuang, earliest Chinese record of O. smaragdina "citrus ants" protecting orange crops
- Bolton, B. (2015). "Oecophylla". AntCat. Retrieved 30 January 2015.
- Rastogi, N (2011). "Provisioning services from ants: food and pharmaceuticals" (PDF). Asian Myrmecology. 4: 103–120.
- Hölldober, B. & Wilson, E.O. 1990. The ants. Cambridge, Massachusetts: Harvard University Press.
- Bolton, B. 2003. Synopsis and Classification of Formicidae. 370 pp. Memoirs of the American Entomological Institute, Vol. 71. Gainesville, FL.
- "Key to Australian Genera of Formicinae - AntWiki". antwiki.org. Retrieved 2023-04-05.
- Crozier, R.H.; Newey, P.S.; E.A., Schlüns; Robson, S.K.A. (2010). "A masterpiece of evolution – Oecophylla weaver ants (Hymenoptera: Formicidae)". Myrmecological News. 13: 57–71.
- Offenberg, J (2014). "The use of artificial nests by weaver ants: A preliminary field observation" (PDF). Asian Myrmecology. 6: 119–128.
- Chen, S. (1991). "The oldest practice of biological control: The cultural and efficacy of Oecophylla smaragdina Fabr in orange orchards". Acta Entomologica Sinica. 11: 401–407.
- Van Mele, P.; Vayssières, J.F. (2007). "Weaver ants help farmers to capture organic markets". Pesticides News. 75 (6): 9–11.
- Sribandit, W; Wiwatwitaya, D; Suksard, S; Offenberg, J (2008). "The importance of weaver ant (Oecophylla smaragdina Fabricius) harvest to a local community in Northeastern Thailand" (PDF). Asian Myrmecology. 2: 129–138.
- Offenberg, J; Wiwatwitaya, D (2010). "Sustainable weaver ant (Oecophylla smaragdina) farming: harvest yields and effects on worker ant density" (PDF). Asian Myrmecology. 3: 55–62.
- Césard N, 2004. Harvesting and commercialisation of kroto (Oecophylla smaragdina) in the Malingpeng area, West Java, Indonesia. In: Forest products, livelihoods and conservation. Case studies of non-timber product systems (Kusters K, Belcher B, eds), Center for International Forestry Research, Bogor, 61-77