|Copyright: manaswi jain (manaswi27)
|Date Taken: 2010-10-11|
|Camera: FujiFilm FinePix S9600|
|Exposure: f/2.8, 1/70 seconds|
|More Photo Info: [view]|
|Photo Version: Original Version|
|Date Submitted: 2010-11-02 6:24|
|[Note Guidelines] Photographer's Note|
Weaver ants or Green ants (genus Oecophylla) are eusocial insects of the family Formicidae (order Hymenoptera). Weaver ants are obligately arboreal and are known for their unique nest building behaviour where workers construct nests by weaving together leaves using larval silk. Colonies can be extremely large consisting of more than a hundred nests spanning numerous trees and contain more than half a million workers. Like many other ant species, weaver ants prey on small insects and supplement their diet with carbohydrate-rich honeydew excreted by small insects (Hemiptera). Oecophylla workers exhibit a clear bimodal size distribution, with almost no overlap between the size of the minor and major workers.  The major workers are approximately eight to ten millimeters in length and the minors approximately half the length of the majors. There is a division of labour associated with the size difference between workers. Major workers forage, defend, maintain and expand the colony whereas minor workers tend to stay within the nests where they care for the brood and 'milk' scale insects in or close to the nests. Oecophylla weaver ants vary in color from reddish to yellowish brown dependent on the species. Oecophylla smaragdina found in Australia often have bright green gasters. These ants are highly territorial and workers aggressively defend their territories against intruders. Because of their aggressive behaviour, weaver ants are sometime used by indigenous farmers, particularly in southeast Asia, as natural biocontrol agents against agricultural pests. Although Oecophylla 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.
Nest building behaviour
Weaver ants collaborating to pull nest leaves together.
Oecophylla weaver ants are known for their remarkable cooperative behaviour used in nest construction. Possibly the first description of weaver ant's nest building behaviour was made by the English naturalist Joseph Banks, who took part in Captain James Cook's voyage to Australia in 1768. An excerpt from Joseph Banks' Journal (cited in Hölldobler and Wilson 1990) is included below:
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 probability of a worker joining the concerted effort is dependent on the size of the group, with workers showing a higher probability of joining when group size is large. When the span between two leaves is beyond the reach of a single ant, workers form chains with their bodies by grasping one another's petiole (waist). Multiple intricate chains working in unison are often used to ratchet together large leaves during nest construction. Once the edges of the leaves are drawn together, other workers retrieve larvae from existing nests using their mandibles. These workers hold and manipulate the larvae in such a way that causes them to excrete silk. They can only produce so much silk, so the larva will have to pupate without a cocoon. The workers then maneuver between the leaves in a highly coordinated fashion to bind them together. Weaver ant's nests are usually elliptical in shape and range in size from a single small leaf folded and bound onto itself to large nests consisting of many leaves and measure over half a meter in length. The time required to construct a nest varies depending on leaf type and eventual size, but often a large nest can be built in significantly less than 24 hours. Although weaver ant's nests are strong and impermeable to water, new nests are continually being built by workers in large colonies to replace old dying nests and those damaged by storms.
Silvio2006, Dis. Ac., siggi, rommel has marked this note useful
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Ciao Manaswi, my today neighbour, wonderful composition with a lot of ants, fine details and splendid sharpness, very well done my friend, ciao Silvio
very nice picture from this plant with ants.
Good of sharpness and details.
Well captured this interesting situation. Good DOf and colours. Well done Manaswi.
- [2010-11-02 12:32]
Verry interesting photo you have here. nice and sharp. Very good composition and colors.Well seen and well done.Best regards Siggi
- [2010-11-02 16:52]
Hi Manaswi,a lot of elements in your rich composition today! And what a sharpness and perfect colors,not easy in this difficult light.Very well done,have a nice day and thanks,LUCIANO
Interseting picture and good notes, thanks for sharing!
- [2010-11-03 2:50]
a common view but very effective one. The red ants are well seen and the nest is well depicted.
The green surroundings is well presented.
- [2010-11-06 3:48]
Good eye to have spotted this unique and interesting image.