HIMENDER BHARTI

In this human dominated biosphere, share a Article place unparalled by any form of life, which our human have now started to reckon with. Feature

earth, out of which more than 12,000 have been discovered, of these about 660 from our country. Ants Friends of Humans Ants play an important role in our survival. Superorganisms They are the major soil turners, channelers of energy, pollinators, scavengers, biological control agents, indicator of the World! organisms monitoring ecosystem health and are important components of our chain. Ants constitute one-tenth of and were witness to the extinction of UMANS recklessly crush these tiny, the total biomass on earth, roughly equal dinosaurs! elegant creatures under their feet. to the total biomass of all the people on The fascinating world of ants has HChildren often take pride in earth. If ants perish human species may received much attention during the last squashing these defenceless creatures. not be able to generate resources and decade or so and they have been given And, of course, none of us gives even a clear debris from earth. Unfortunately, with the status of ‘Superorganism’, much fleeting thought to their existence at all growing penetration of anthropogenic superior to human species in terms of and think of them as irritating pests that activities in natural ecosystems, about a development, intricacies and evolution. should be got rid of. dozen species have turned pests. Due to their great adaptability, ants have Most of us are unaware of the fact Monomorium pharaonis (Pharao’s ant) is a occupied every possible niche or habitat that ants are an important and common example of this. indispensable part of our ecosystem. found on land, forest canopies, rotten logs, These tiny creatures have existed on earth crevices, and braved the freezing World of Ants much before the arrival of the human temperatures of high altitudes. Almost An is built up by the queen ant. race, originated 145 million years ago 30,000 species of ants are estimated on After its , a fertile queen finds a suitable nesting site for laying eggs. The eggs hatch into tiny larvae. The first batch of larvae is tended by the queen itself. The The Queen Ant larvae change into pupal stage and finally

Food shared by ants

19 SCIENCE REPORTER, MARCH 2012 Feature Article

Ant with brood Leafcutter Ant

Army Ant

Redfire Ant

Harvester Ant Ant frightens death

High Altitude Ant

Jumping Ant Weaver Ant

Weaver Ant Nest Trapjaw Ant

Ant with Larva

“The neglect of ants in science and natural history is a shortcoming that should be remedied...” Bert Holldobbler The workers exhibit a variety of behaviour – cooperation with nest mates, defending the nest from robbers, organizing food raids, looking for the best food, tending to the immature ants in the nest etc. All their efforts are targeted at ensuring the survival of the colony.

SCIENCE REPORTER, MARCH 2012 20 FFFeaeaeaturetureture Article

In this era of technological revolution, the nest where fungus is cultivated to digest leaf cellulose. The most interesting part of ants are far more superior to advancing technology. the story is that if even the most advanced human species is forced to live with fungus Many of have been grouped culture, it may not be able to bear the Scientists have even studied the on the basis of specific tasks performed brunt of pathogens, but these behaviour of ants to develop a by them. These include: a) Harvester ants, superorganisms are least susceptible to b) Weaver ants, c) Leaf-cutter ants, d) Army new generation of antivirus such infections. The resistance developed ants and e) Fire ants. software for computers. is unparalleled in any form of life. a. Harvester ants: The harvester ants have been named so as they harvest seeds of d. Army ants: This group contains more than different types of grasses and mainly 200 ant species. In our part of the world the first batch of workers emerges. These belong to Messor, Pognomyrmex and these belong to Aenictus and workers then take up the responsibility of Pheidole genera. These can be easily genera. These carry raids in groups feeding the young ones – the larvae as spotted in a garden, park or lawn where attacking prey en masse. Army ants can well as the queen. The worker caste they create corridors or passages on land consume up to 100,000 prey each differentiates into soldier caste, foragers, which look like passages created by day and thus have a significant influence feeders etc. and works on the principle of repeated movements of humans. The ants on the population, diversity, and behaviour division of labour. collect grass seeds, remove their plumule, of their prey. Army ants on the march are Thus, a single ant colony with a set so that they don’t germinate and store known to kill tethered horses, human of workers performing different tasks can them in well-kept nest godowns. After babies, lizards, snakes, chickens, and small be compared to the human body where consumption, the hard seed coats are mammals. They also climb trees and attack organ systems perform different thrown out of the nests and can be noticed birds in nests and have even been used to functions. In this way, an ant colony is in abundance outside their nests. execute criminals. These don’t make established with one colony containing permanent nests like other ants, instead up to 20 million workers. During the b. Weaver ants: As the name suggests they build a living nest with their bodies, known reproductive phase of the colony, the weave nest with leaves. One of the as a bivouac and keep moving like queen produces future queens and prominent groups in this category is nomads. It is a treat to watch a moving males. The queen ant may live up to 20- Oecophylla. These can be spotted on column of these ants in tandem and 30 years, worker ants up to 60 days and mango, citrus and guava trees and are rhythm without exchanging a single word. males for few days, their main task is to quite ferocious in nature. These ants exhibit It can make the most efficient army of the inseminate the female. marvelous architecture and intelligence world envious. The workers exhibit a variety of to build their nest with leaves. The workers behaviour – cooperation with nest mates, capture their larvae quite delicately in their e. Fire ants: Fire ants include a variety defending the nest from robbers, jaws and move them to and fro on the of stinging ants with more than 285 organizing food raids, looking for the best edges of young tender leaves, in response species worldwide. They have several food, tending to the immature ants in the to this movement or tingling feeling, the common names, including ginger nest etc. All their efforts are targeted at larvae release sticky material from their ants, tropical fire ants and red ants. The ensuring the survival of the colony. They glands. Then the other workers fold these most commonly heard fire ant is Solenopsis are a unique example of unbinding co- leaves and join them with the secreted invicta, known in the United States as operation and high degree of glue. To join the two leaves (which are quite the red imported fire ant (RIFA). It is an unselfishness. apart), ants form chains by holding each invasive pest in many areas of the world, While performing all these tasks other’s waists and thus pull the leaves notably the United States, Australia, thousands of workers communicate for together. the Philippines, China and Taiwan. The smooth functioning of the colony. The ants Weaver ants are used in biological RIFA was accidentally introduced into the do not communicate verbally, or visually, control to increase fruit yield and their United States aboard a South American but use the language of chemical cues to brood is used in Chinese soups, drugs, as cargo ship that docked at the port communicate. Ants release specific food and as aphrodisiac in many parts of of Mobile, Alabama, in the 1930s, and chemicals called pheromones along with the world. came to infest the majority of the tactile cues (tapping each other’s Southern and Southwestern United States. antennae) to elicit a specific response c. Leaf-cutter ants: This group contains In our country a similar species Solenopsis from fellow workers. They use a blend of about 47 species belonging to the genera geminata exists. chemicals for recruitment of nest mates Atta and Acromyrmex. These are endemic Unlike many other ants, which bite and for collecting food; or to alert the entire to Central, South America, Mexico and then spray acid on the wound, fire ants colony when attacked by intruders. United States. Leaf-cutter ants initiated only bite to get a grip and then sting (from Moreover, a unique colony odour is agriculture much earlier as compared to the abdomen) and inject a toxic alkaloid present in each ant’s nest, which is released the human species. These ants bring fresh venom called Solenopsin, a compound by the queen ant. Thus, each colony has a leaves and plant cuttings into their nests; from the class of piperidines. For humans, specific odour by which its members which are further cut into smaller pieces this is a painful sting, it hurts, a sensation recognize nest mates from non-nest and are treated with ants’ faecal liquid. similar to what one feels when burned by mates. Then these are dumped into that part of fire—hence the name fire ant. 21 SCIENCE REPORTER, MARCH 2012 Feature Article The next step in this direction is the Ants play an important role in comparison of various ant genomes to Adapting Ants our survival. They are the major study how the invasive species have Ants have adapted to high altitudes well diverged from their native counterparts and such ant species are termed as cold soil turners, channelers of and whether pesticides like DDT could hardy species, since they can survive in energy, pollinators, scavengers, have accelerated ant evolution. The subzero temperatures of winter. Himalayan biological control agents, genome of red (which is a ants belong to this category and recent model for studying reproductive division discoveries of new species from Himalaya indicator organisms of labour, phenotypic plasticity, and by the author and his team has revealed monitoring ecosystem health sociogenomics) revealed that gene that these ants are quite distinct in their and are important components networks involved in generating key features and have diversified in this region differences between the queen and after the formation of the Himalayas. of our food chain. worker castes (e.g., wings and ovaries) The most significant discovery is a show signatures of increased methylation. potentially redlist socially parasitic species These findings indicate that ants and bees named as Myrmica nefaria (nefaria Unraveling Ants may have independently co-opted the means robber). This species has very The wonderful world of ants has been same gene regulatory mechanisms for unique features, and has been reported explored by researchers to unravel reproductive division of labour. with males and workers along with host marvelous pieces of scientific information. The leaf-cutter ant, which cannot species and exemplifies the concept of The genome of six ant species has already survive without its fungus food, has slimmed sympatric speciation (the formation of been worked out, which include its genome to get rid of those genes it no species with in the same region without Harpegnathos saltator (jumping ant, longer requires due to its symbiotic life style. geographical isolation contrary to the common in India as well), Camponotus Thus the evolutionary trades of one of the widely accepted view that new species floridans (Florida carpenter ant), Atta most successful association in nature are formed due to some geographical cephalotes (leaf cutter ant), Linepithema between leaf-cutter ant and its fungus can barrier like mountains etc.). humile (Argentine ant), Pognomyrmex be read through DNA. Queens of socially parasitic ants barbatus (Red harvester ant) and Such is the importance of these world’s invade the nests of other ants by using Solenopsis invicta (Red Fire ant). premier social organisms that “An Ant Tree various means (by killing the host queen, Ants of the same species but in of Life Project (Ant AToL))” is being carried picking up scents of the colony or different social castes have the same DNA to understand their evolutionary patterns. mimicking CHCs of that particular colony sequence but assume radically different Besides, a big Barcode initiative of life has so that they are not noticed) and capitalize characteristics as a result of ‘epigenetic also been initiated for ants as well, where on the host resources without using their changes’ — DNA modifications that affect DNA barcodes of all the ant species energy. Thus they don’t produce the worker the expression of genes rather than the present on earth are being generated with caste and are termed as inquilines. genes themselves. By examining the active participation from India also. Moreover, 94% of the Himalayan ant fauna sequences from jumping ant and Florida has been found to be endemic to this carpenter ant, researchers have been Communication in Ants region and due to its exceptional features able to identify how these epigenetic Ants communicate by biological or adaptive strategies needs conservation. changes affect the ants’ characteristics. molecules; of much interest in recent times Ants of leaf litter are mostly specialized The results provide a tantalizing link among these molecules are cuticular predators and are of interest to between ageing mechanisms in ants and hydrocarbons (CHC) which provide researchers. In the last decade more focus other organisms. Two genes in case of important cues for nest mate and caste has been to look for leaf litter ants and jumping ant, one encoding the enzyme recognition. Scientists have already one of the remarkable discoveries is the telomerase and the other encoding the elucidated CHC profiles for about 80 ant ant (Martialis means from protein SIRT1, are also associated with species. Such 1000 different CHCs have Mars and heureka means surprising longevity in humans. been recognized, which act due to discovery) from the Amazon rain forest, In the case of Argentine ant, 367 switching on or off of particular biosynthetic which has shed light on the evolutionary genes are meant for odour receptors pathways. patterns in ants. In our country, Western (twice in number as compared to honey A very interesting piece of Ghats also harbour a number of leaf litter bee), which help to distinguish between information which appeared online ant species. their friends and enemies. In fire ant recently in the journal BMC Ecology Due to a great deal of anthropogenic genomics, G C content in DNA has been reveals that a newly described species activities invading in to natural ecosystems found to be 34.8% similar to most of of silver fish (Malayatelura ponerophila) the world over, these ecosystems are eukaryotes and the genome is much larger spends its entire life among a colony getting disturbed. To measure such and complex than most . Since of army ants (Leptogenys disturbances indicator organisms that are both fire ant and Argentine ant are invasive distinguenda). To avoid being spotted, supposed to encapsulate all information species, disrupt ecosystems, and harm it rubs against baby ants to pick up their about the ecosystem or which act as crops, the genomes would help ascertain scents i.e. CHC profile, so that the smart surrogate organisms for that ecosystem how to use the ants’ reliance on its own silver fish gets free food and shelter and are used and ants have been found to be odours against them without using is considered part of family until it has most effective indicator organisms. environmentally toxic pesticides. the scent. Researchers in developed nations have SCIENCE REPORTER, MARCH 2012 22 Feature Article AMAZING FACTS ABOUT ANTS The first comprehensive book on honeydew and in turn protect their Ant colonies can cross river by ants entitled “The Ants” written by cows from predators. combining themselves in to water Bert Holldobler and Edward Wilson tight balls and floating until the ball was awarded the prestigious “Pulitzer Many plant species have developed finds dry land. Prize” for General Non-Fiction in special structures to harbour ants, 1991. ants make their nests in these The Slave-Maker ants raid the nest structures and the plant gets of other ants, steal their pupae and Ant specialist and biologist Edward protection in return. once the pupae hatch, they are used Wilson was awarded Crafoord Prize, as slaves in the colony. 1990, a prize awarded by the Royal Ants remove dead bodies of fellow Swedish Academy of Sciences in mates and debris to maintain hygiene Some ants don’t produce workers, certain sciences not covered by of the nest, on the contrary some the queen enters another queen’s the Nobel Prize, and therefore species keep fragmented body parts nest, kills the host queen and dictates considered the highest award given of their colleagues as remembrance in terms to the host workers. their nests. in the field of ecology. Fire Ants cause the most bites and Ant brain contains 250,000 Infected or diseased ants perform deaths among other ant species, about neurons, the largest brain among less social interactions, so that others 20 deaths in the world per year. are not infected and spend most of insects and the largest in proportion In United States $5 billion is spent their time outside the nest before their to body size among all animals on annually on medical treatment, death. earth. The processing power is damage, and control in Red Imported almost similar to Macintosh II Some ants show jumping behaviour, Fire Ant infested areas. Furthermore, computer. some feign death when captured, the ants cause damage annually of Ants which do not have a sting some show aggressive postures. about $750 million to agricultural squirt a spray of formic acid in In the deserts of Arizona, Harvester assets, veterinarian bills, defense. ants collect seeds in the day time, but livestock loss and crop loss. In some ants jaws are held open during night a different species of Red imported fire ant (Solenopsis from 180° to 270° and snap shut on ants covers up the nest holes of invicta), tropical fire ant (Solenopsis a hair trigger to capture the prey. Harvester ants in order to block the geminata) the big-headed ant entrances. So that the other species (Pheidole megacephala), the little fire More than 40 chemicals are used could collect seeds during night and ant (Wasmannia auropunctata), the by ants for communication. the next day, when harvester ants Argentine ant (Linepithema humile), In some species, workers vibrate waste most of their time to unplug the yellow crazy ant (Anoplolepis their heads or bodies against some entrances. gracilipes), Pharao’s ant (Monomorium wood or nest structure, when the The leaf cutter ants are of immense pharaonis),Singapore ant (Monomorium queen ant is passing by to inform importance in tropical and sub- destructor) and black crazy ant other members of the nest about the tropical ecosystems and are also major (Paratrechina longicornis) are the major location of the queen. pests in cultivated fields of Central species of tramp/invasive ants, Ants also domesticate cows like and South America and harvest about known to cause devastating humans; these cows are aphids, 85-470 kg (dry weight) total plant ecological effects. Out of these, five mealybugs and other insects. These biomass per colony per year. (tropical fire ant, big headed ant, yellow crazy ant, Pharao’s ant and plant sap-sucking insects excrete Ants are also smuggled and colonies Black crazy ant) have already spread material rich in nutrients called are kept, the trade known as ant in our country as well. honeydew, ants feed on this farming growing day by day. successfully used ants as indicator conducted, so that the dispersal of Holldobbler, “The neglect of ants in science organisms to assess the health of organisms after the formation of and natural history is a shortcoming that deteriorating ecosystems. continents could be better worked out. should be remedied, for they represent Interestingly, the same mechanism In this era of technological revolution, the culmination of evolution, in the has also been used in our country to assess ants are far more superior to advancing same sense that human beings represent the health of the Shivalik range of Himalaya technology, because scientists have even the summit of vertebrate evolution” . (which is currently under stress due to studied the behaviour of ants to develop a human activities) by the author and his new generation of antivirus software for team. It has been found that this range of computers. So, in this human dominated Dr. Himender Bharti is with the Department of Himalaya has been invaded by alien biosphere (noosphere) ants share a place Zoology and Environmental Sciences, Punjabi species of ants that displace native unparalled by any form of life, which our University Patiala, Punjab-147002; Web: species and imbalance the ecosystem. human species have started to reckon with. www.antdiversityindia.com; Email: To understand bio-geographical patterns To put in the words of great biologists [email protected]/ of ants on earth various studies have been Edward Wilson and ant specialist Bert [email protected]/ 23 SCIENCE REPORTER, MARCH 2012