E-Kantipur

Now, having been bitten by a wasp on the nape of my neck (here’s a tip: if this happens to you, place a raw potato slice on the bite—it takes the sting out!) I can understand people’s fear of wasps. But like anything else in life, if you choose to rise above your own prejudices, you will find a fascinating world full of drama all around you. And nothing typifies it more than the wasp.

Our wasp is a truly complex being. It is precise, determined, and aspires to overcome the largest obstacles with intelligence. Take the nests they dig out: the Bembix rostrata digs into the ground like an excited puppy, scratching the sand out continuously and throwing it backwards between its hind legs. The Cerceris tuberculata pick up bits of gravel from the bottom of the pit with its mouth, and disposes of it outside. Then a group of Sphex flavipennis works together by rolling away this detritus.  If one piece is too heavy, the wasps huff and puff with shrill, ‘hoo hoo!’-like screams.

Nests themselves are fascinating. Some wasps build their homes on tree branches, others in tree holes, and more underground, in already existing animal burrows and lofts. All of them have one thing in common: they are master craftswomen (all the workers are female). The Eumenes wasps decorate their nests with shells and pebbles.  But how do they make the nests? The social wasps chew wood with their saliva until it becomes like soft, like paper. They make great wasp cities, combs of perfect hexagonal cells which architects say are the most useful and economical  form of building in nature. They use them for only one season and then make them all over again the next year.

So, what do they eat? While the adults subsist on pollen and nectar, they hunt insects for their offspring. They bring in beetles, caterpillars, spiders and crickets—all far larger than themselves and all alive, if yet paralysed. The female will often choose a caterpillar more than ten times her weight. She grips him by the skin of his neck and holds tight, despite his writhing. Carefully and deliberately, she inserts her needle-like stinger into each segment of his body, moving methodically from ring to ring, from up to down, each one in the precise place where the caterpillar has its nerves. She then squeezes his brain so that the caterpillar goes into a coma, before dragging him into the nest. She places the caterpillar in a chamber, and lays a solitary egg on it.

Evidently the entire operation is thorough, and she uses exactly enough poison to keep the victim alive, but immobile so that the flesh does not putrefy.  When the egg hatches, the larva can feed on the still-fresh meat: eating the live caterpillar bit by bit until the larva grows into an adult wasp. Could an untaught human be so perfect in his or her hunting skills? Some wasps will provide as many as forty spiders for each larva.

Nature’s drama is never-ending. The Alcon blue butterfly lays her eggs near an ant nest. The newborn caterpillar exudes a smell similar to that of the ants, and so they carry it off to their nest as one of their own, where they will feed and nurture it. However, the ichneumon wasp wants the caterpillar to feed her own babies. So she enters the nest and sprays a chemical that causes the ants to fight with each other (America, are you listening? Why not just use a spray in Iraq, Afghanistan, Libya?). Amid the confusion, it finds the caterpillar and injects an egg into it. Once the ants return to normal, they continue to feed and groom the caterpillar until in a few days what emerges from its torn body is a wasp baby.

Surprisingly, even when wasps die, they are helpful to the end. They release a smell which will warn other wasps of the lurking dangers, as an indicator that help is needed. Female bee wolf digger wasps have colonies of bacteria that inhabit their antennae. When their babies become cocooned, the mothers inject them with these bacteria, which scientists have now found to be antibiotic. This is the first non-human use of prophylactic antibiotics to fight infections

found so far. Female workers help the queen wasp in increasing the population of the nest by laying eggs, but as soon as the nest fills up, the workers become sterile. If only humans could do the same! Engagingly, there is only one way in which the wasp is similar to the human. Some occasionally feed on fermented fruit, get drunk, fight and pass out. Oh yes, and they like sugar fixes. The wasp is an important source of food for dragonflies, beetles, moths, birds, bears, badgers, bats, weasels, rats—and of course the Chinese. So be kind to a species that is not just smarter than you but much more useful.

       gandhim@nic.in

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