Mother Wasp

…think wasp is a stinging machine? Think again.

It was a sultry day in 2008. The October heat had set in. We were in the field taking a break under a small Teak tree, sipping on the little water left with us. The grass was tall and green but the characteristics of a deciduous forest were already showing. There was no wind – which is typical of October and the humidity was at its peak. We were downright exhausted and had decided to sit under the Teak which provided the only little shade around. We’re glad we chose that place, for we observed a very interesting behavior in the big world of little creatures.

I chose to sit in the grass where the area was dense enough for various critters to crawl around. I saw some movement in this undergrowth and for once thought it was a scorpion! I was super excited, a scorpion sharing the shade with us! After a few glimpses of this ground-walking animal, I saw that it was a wasp carrying a huge caterpillar in its mandibles – the prey was double its size and must have weighed more than the wasp itself.
As seen walking in the undergrowth
That very moment I forgot how exhausted I was, how the sun charred my skin and how my throat screamed for water. I took some shots of her walking in a considerably straight line – towards god knows what. The story breaks here.

Let’s have a look at this insect first. It was a wasp, a Hymenopteran. It was carrying a caterpillar in its mandibles, hence a predatory wasp. It had a slender abdomen – much like the thread-waist wasps so it could belong to Sphecidae. The caterpillar was 8 cm in length. It was a semi-looper caterpillar and hence belonged to the moths. I suspect it belonged to Catocalinae – a diverse family of moths, most of which are termed Fruit Piercing Moths that act as pests. Now we have a closely identified wasp, but are unsure if it’s a Mud-dauber or a Digger. We will find that out soon. But we know who the unlucky prey was.

The story commences. So there is this wasp carrying a big caterpillar – walking all the way downhill on a hot October day. That’s some stamina alright. I can only speculate how she captured the prey. Finding such a big caterpillar would not have been difficult since these predatory wasps are experts in finding and capturing prey. What’s surprising is how she managed to lift it and walk all the way here. I emphasize on “walk” because that’s how I saw her at first. She was walking – she perhaps could have been flying before – but considering the bulk of the prey I am not very positive whether she could fly or not. Now the way was close to 10 feet – long distance for a two inch wasp.
Making her way through the obstacles
She made her way through the thickets and often disappeared into the fallen leaves – appearing once in a while. She was non-stop on her trek, did not wait unless something blocked her way and she stuck to her near linear line-of-walk. I can only imagine how she managed to do that. But let’s answer that later.

Where she headed was still a mystery until my friend spotted a little hole in the ground. Yes! A hole in the ground, yes, it is a solitary Digger Wasp. There are three Subfamilies Sphecinae (Digger wasps), Sceliphrinae (mud-dauber wasps) and Ammophilinae. This particular wasp belongs to the last Subfamily, in the genus Ammophila.
A neatly dug nest of the Digger Wasp
In summary, the Digger Wasps sting their prey – which can be a cricket, a grasshopper, and any other insect, paralyze it and carry it along to the nest – a burrow. The wasp collects enough prey and stacks it into the nest, and then lays eggs. But some species of solitary wasps stack only one prey and lay a single egg. The prey is only paralyzed hence is alive, and as soon as the grubs hatch, the food is served fresh.

This is the sole reason why I decided to title this post as “Mother Wasp”. We often think that only higher animals show motherly care towards their young ones; and forget how hard working these little animals are towards a successful progeny of theirs. This care for the young ones is seen in many insect groups, from social ants, bees and wasps to solitary ones including hemipteran bugs, beetles and flies. It is true that all the “motherly” behavior is inbuilt in their genes, but let’s not forget – it is inbuilt in our genes too but ours is also affected by the environment we live in.

The story resumes. After a long walk through the thickets, the she-wasp was near her destination. This is when I started to wonder, how in this big world did she find her way in? I mentioned she walked in a strict straight line. Had she been flying, she could have easily seen the burrow through some landmark – for instance, the teak tree. Here she was walking with a burden and reaching the target without any effort of searching around for it. She must have used the mid-day sun to navigate. Many insects do it such as bees and ants. But this behavior of using the sun to navigate makes me wonder about a lot of other things.
...reaching the nest site
The story pauses here. Let’s assume she used sun to navigate. Her nest was downhill (on a slope), and the sky was clear. The nest was below a shady tree but was easy to spot. All of this tells me that this wasp is diurnal, which is obvious, but it also gives me an idea of the time when she hunts. It is possible for such a wasp to navigate on ground or in air with the help of sun as the compass. But here I assume that navigating through the thickets during mid-day is easier than at dawn or dusk. I wonder if they have specific times for hunting.

The story resumes. The wasp carried the paralyzed prey and set it beside the nest. She went inside the burrow to inspect it – she spent about 30 seconds inside the nest, throwing out little stones. I stooped over, without disturbing her and photographed whatever movements she made.
Notice the injury on the ventral side of the caterpillar - that's where the wasp stung the prey
She inspected the burrow a several times, often getting some soil off the nest.
Inspecting the burrow and making room for the prey
An interesting observation by Daniel Dennett showed that – when the wasp drops the prey beside the burrow and goes inside to investigate it, and if the prey moves (or is moved), the wasp does locate it, brings it back, drops it beside the burrow and goes inside to investigate again. Every time the prey moves, the wasp does the same act. This mechanical behavior is how he describes as an example of “how seemingly thoughtful behavior can actually be quiet mindless, the opposite of freewill (that is Antisphexishness)". For a more elaborate read – visit HERE.

After inspecting the burrow – possibly adjusting the stack that is already stored inside and clearing tiny stones from the nest site – the wasp grabbed the prey and receded inside the burrow. This did not take very long, and within a few seconds, the large prey was well inside the nest. I am unsure if she laid the eggs before the caterpillar was taken in or after – since she appeared outside very quickly, but I assume she laid one egg each on the paralyzed prey inside.

Three sequence shots taken when the wasp dragged the paralyzed caterpillar in the burrow

Now was the time to cover the nest. The wasp came out after a couple of minutes and started burying the nest. This task was not something very random, but she put in just as much effort in burying the nest as she must have in making one.
Carefully covering the burrow with a layer of lose soil
The wasp carefully shifted only the soft soil into the burrow and occasionally separated large soil particles off the nest entrance. The work was exhaustive and she took several turns to clear the large particles by her mandibles and then turning her back towards the entrance, she would shove soil onto the entrance by her hind appendages. She repeated the steps several times until she was satisfied by the quality of soil on top of her nest. The larger particles (stones, really) were carried in the mandibles – which she did not throw aside but preferred to fly a feet from the nest and drop it. This peculiar behavior also interests me, and I haven’t come across a reason why she chose to throw it well away from the nest. Perhaps because it might fall over the nest again - another genetically inbuilt behavior?
Removing any larger soil particles off the burried nest
Following are a few more sequences of her laborous work to cover the nest.
Three sequences showing the wasp covering the nest-site (1st picture), removing larger soil particles (2nd picture) and again covering the nest-site with finer soil
After all the taxing work of a mother, which took several minutes, and after standing in the mid-day sun, bending over and making absolutely no movements – the nest-site looked perfectly neat and clean. It’s as if there was no burrow at all. The task was over. The grubs had enough food to eat. Her motherly duty was completed – she laid eggs, provided food and provided protection. The wasp flew away, never to return.
Here once was the Digger Wasp burrow!
This little natural history has been followed and studied for years. The millions of years of evolution have made these little creatures masters of their skills. I had seen another wasp carry a katydid and fly to her nest in a hurry in the same area. They are there all around us, doing their daily job of looking after their young ones, making sure their species survives. It may seem very mechanical, the way they behave, the way things are, but they are not living without benefiting the ecosystem. They have a purpose that is not mechanical.

In case of the Digger Wasp, they are predatory as we know it and prey on pest populations such as crickets, katydids, grasshoppers and caterpillars. Thus they not only protect a certain plant from being eaten, but also keep their population under control and act as natural pest controllers in agricultural fields.

Thank you for reading.

1. Observations on the Nesting Behavior of the Digger Wasps of the Genus Ammophila by Howard E. Evans
The paper discusses the Ammophila genus in detail along with detailed information on how the wasps carry their prey, the nest size and other observations. A must read if you read this blog article.
2. The Evolution of Prey-carrying mechanisms in Wasps by Howard E. Evans
An in-depth look into the elaborate behavior patterns of Wasps, their ancestry, mandibular and pedal mechanisms.

International Biodiversity Year

“When we become a part of anything, it becomes a part of us.”
- David Harold Fink
Seedlings sprout from the dried fruit that is 
still clinging to the mother tree during Monsoon
A new year is something everyone looks forward to. 2010, however is not just another year, it is the end of a decade. 2010 is, most importantly, declared as an International Year of Biodiversity. Keeping this in mind, I wonder how many of us have really emphasized on the biodiversity around us. It’s certainly not many, because if many did, we would not lack the knowledge and understand of nature and her ways even today.
Neanotis lancifolia flowers barely measure a centimeter
 and these little Daggerflies are seen enjoying on this tiny herb in bloom
To acknowledge the year 2010 as the biodiversity year, it’s us as the citizens of this planet who must stand up and face the truth. The truth – had it not been for this biodiversity, we would not exist. Some of us may think, so let’s consider a cockroach or a mosquito into our “biodiversity appreciation” year, and learn to live with them. No. I don’t mean only cockroaches and mosquitoes, I mean every living organism that you can and can’t see. I mean those elephants that are killed for ivory (click HERE to read on the latest news on Global Ivory Trade), and those rhinoceros poached for their horns, I mean those tigers left in the Indian forests, and those Cougars of the northlands. I mean those butterflies and birds poached for their beauty, and those insects that end up in someone’s rare collection. I mean everything and everyone, including us.
Gushing waters during Monsoon is common and a best site for observing biodiversity
 but often such sites are teeming with ignorant tourists
So how do we go about this appreciation of biodiversity? I am sure some may ask. Do you want us to pick up every insect and whisper sweet words to it? Or maybe go kill a poacher and be happy? It is not easy, I agree. But there are little things that are easier.
A disheartening landscape - a view of the behind of Bazar of Matheran littering the valley beneath with tonnes of waste
Such easier things are:

• Stop throwing plastic. Oh, you don’t, is it? I know most of us don’t, so do you pick it up? No you don’t. And no one expects you to pick it up either. But when we are in a forest, walking for our visual pleasure, taking photographs and admiring nature, we always come across a piece of plastic ruining that landscape. Pick that up. It’s always relieving to see that piece of plastic in the garbage-bin than in a forest. This drive, which starts from you and I, if spread into everyone’s mind – can make a big difference.

• Stop throwing paper. Now we know it is biodegradable and safe to dispose. I don’t blame you for throwing paper, I know you don’t (and wont) but the paper – a product of the forests itself, is no more a “true” product of the forest. It gets processed in factories that use fuel to drive them; it gets acidic due to heavy bleaching, and hence not quite comparable to its initial environmentally-friendly form. Instead, it is better to recycle all paper and paper products. So dumping the useless papers into recycling-bins is better than letting them decompose in nature.

• Stop using plastic bottles. There was a time, not a decade ago when all of us as school kids used to hang a water-bottle in our necks and drink from it. It has changed, for bad. Now we use the disposable bottles which we use-and-throw. Reusing them does sound like a solution but then it is not good for health either, so we recycle them, but we basically discard them. Recycling is more of “downcycling” where the quality of a recycled product is not as good as the previous. So why not stop using them? Why not carry a water-bottle in your backpack and refill it whenever possible? This will save the evil plastic corrupting our brains and polluting our forests!

• Stop smoking in forests. For nature’s sake, this is not a place to smoke! I have seen people drink and smoke in forests; these kinds are as responsible for causing pollution as the traffic is in forested areas. A small puff is enough to pollute the fresh forest air. Do not expect the huge trees to clean up your dirty work, no plants can clear the toxic compounds released into the air caused by smoking.

• In the lines of polluting the air, stop (or minimize) using personal vehicles as a means of travelling to wild places. A public transport is always available and accessible. More vehicles in a forest lead to obvious pollution, which we do not realize in the sheer excitement of being in a forest. This is the biggest problem when tourists flock to the pristine wilderness. If we use the public transport – owned by the government itself, we not only reduce our impact on the health of the ecosystem, but also contribute to the economy of that place for good.

• Go on a vacation, locally. This is debatable, but it was brought up by my friends who emphasized on the fact that there is so much to look around wherever we live – within a day or less distance, that we seem to ignore these places completely and yearn to visit far and wide. It is our right to explore, visit new places, and have fun. But that new place could well be near you. Most of us might not agree with this, but if you are an explorer, you sure would explore and learn about the creatures of your backyard first.

• Don’t flock to see a tiger. Yes, sounds too thick, but hey, there are about twenty jeeps lined one after another to see a tiger. I wonder how much pollution the tiger has to live up with now-a-days? Ever wondered how the tiger feels? Now there are no human-like emotions in tigers, but they do feel the stress, which can change their behavior for bad, for instance being used to public, or worse still, disrupting their hunting pattern.

• Lastly, remember the three R’s. The three golden R’s to save our environment. No not the Reduce, Reuse and Recycle. The new “revolutionized” three R’s stand for Reduce, reduce and reduce! If we do not reduce our consumption, we will never get better.
Tourists flocking to Mahuli Fort during Monsoon - such places need to bear hoardings stating ban on using plastics,
smoking and alcohol and encouraging public transport in the locality
There are many more such as eating locally, using public transport daily, switching off the lights, and so on. The issues mentioned here are read and heard about everywhere, but there is no concrete action taken by us, is it true that we will stop littering only when the government slams a fine on us? The little actions we take can indirectly affect our impact on the ecosystem. We must move a step forward now, and promise to lead the way for our narrow-minded followers. Let’s start from us, let’s not wait for someone to lead the way. Let’s not look up to the municipality and wait for them to clean up. If we don’t take this simple responsibility, we cannot appreciate the biodiversity, and fail the 2010 International Biodiversity Year.

My aim is not to emphasize on the “International Biodiversity Year”, but on spreading the message of awareness and taking responsibility ourselves. 2010 IBY is just a means of reaching out to the people, making them think twice before buying illegal, poached products and sensitizing them on the issues of extinction dawned upon nature by us. If we begin to appreciate the sheer biodiversity around us, develop a sense of being within that rich biodiversity and believing that it is our responsibility to protect it, then that’s it, the world has never seen a year as beautiful as 2010.

In the last few years, I learnt a few things about nature, and working with WWF – India, MSO helped a lot. The experience of working with senior folks in the community of ecology, and other like-minded colleagues has been a tremendous help in absorbing the knowledge, through excursions and through sharing experiences. It will not only prepare you to be a better naturalist, but also make you conscious with what’s going on in the field of environment and ecology. In this context, I will also suggest you to become a part of any nature-related organization, such as WWF, BNHS (and others in Mumbai are HERE) and Nature Canada, Ducks Unlimited, Earthroots (and others in Ontario are HERE) and other various local NGOs working in favor of the environment.

Some general information:
Green Grades to techno giants

Last but not the least, there are a million things we can do. Let’s begin from scratch. Let’s start from our very home by doing this little.

The winter is grim now. It’s just going to be a lot of “looking back” on previous nature-walks for me, and pondering over the environmental issues and going in pursuit of sustainability.