Phenomenal Nature - Migratory Locust Swarms
Last week I wrote about The Great Wildebeest Migration, a truly amazing phenomenon of the natural world that I would desperately like to see for myself.
Today I’m going to stick with the theme of an amazing phenomenon of the Animal Kingdom, Great Migratory Locust swarms and the devastating impact they can have on an afflicted area, it goes without saying I likely won’t be setting up a savings account to see one of these Swarms for myself.
Migratory Locusts
Migratory Locusts are polyphenic, meaning they display several different physical traits throughout their lifecycle based on their environment. The two main phenotypes of the Locust are solitary (no interest in migration or swarming) and gregarious (constantly moving for food in dense populations), solitary Locust will be brown/green in colour whereas the gregarious Locust will be brown/yellow and smaller in size.
At the inception of the swarm population most Locusts will be solitary, this changes as the population density increases, as a response to overcrowding the Locusts begin to change colour, feed more regularly and breed at a faster rate, these changes are triggered by a release of Seratonin within the Locust that occurs after tactile contact.
The resulting offspring will also be born with these traits, at this point the swarm will continue to grow at an exponential rate and migrate great distances until their food supply has been exhausted, the swarm will then diminish in size, before transitioning back to a small group of solitary Locust.
This method of transitioning and adapting both physically and socially allows the Locust to maintain steady numbers and allows for their food source to replenish, as such, this life-cycle functions flawlessly during regular weather seasons.
Another transition the Locusts undergo is a striking physical change which occurs in both solitary and gregarious Locust, over the course of a Locusts life it will shed its exoskeleton on five occasions where it will grow slightly larger until it has reached adulthood, the first five phases are referred to as Instars, through Instars one to five the Locust is limited to life on the ground, during these phases they pose a limited threat to isolated areas of land and are fairly easy to control.
It’s not until the fifth and final Instar that the true potential of the Locust is seen, at their next shed they become adults and grow a set of wings, thus allowing them to travel to more bountiful feeding areas should their current territory become sparse. Flying Locust can cover vast distances, they fly with the wind and can reach speeds of up to 20 Km/h, this allows them to feed and strip wide areas of land in a very short time frame.
The Calm Before the Storm
When referring to Migratory Locusts, the term ‘the calm before the storm’ is a fairly accurate way to describe the initial phase of the phenomenon. Migratory Locusts will inevitably go through a phase where a swarm of some magnitude will occur, however the size of the swarm will be entirely dependent on the environmental conditions at the time.
To enable a swarm the most ideal weather conditions consist of heavy rainfall in temperature regions, this weather allows vegetation to flourish and provides ample food and cover for breeding insects to thrive, one of the more common modern day swarming Locust species is the Malagasy, the Malagasy appears regularly in Madagascar and will swarm annually, often with limited negative impacts on the country as a whole, issues do however arise during periods of extreme weather, an occurrence that is only predicted to rise as the Earths climate continues to change, the example in this article will centre on the Madagascan swarm of 2013, though, there are several other notable swarms that have occurred in the past century alone.
As mentioned, the Locust only swarm when in their gregarious phase, a solitary Locust population is not an issue unless you have a passion for trekking but also possess a phobia of large Insects, solitary Locust populations can still number in their thousands, but the population remains stable until a clear trigger event occurs.
Enter Cyclone Haruna
Whilst the government had prepared for isolated swarming they were not prepared for the worst-case scenario, which just so happened to occur in February 2013, Cyclone Haruna hit Madagascar and devastated the country on many fronts. Flooding, disease outbreak, crop destruction and structural damage resulted in large areas having no electricity or drinking water and many were left homeless.
The damage and effects of the Cyclone itself would have been enough to declare the event a tragedy, but the struggles were only just beginning, the mass rainfall and warm weather provided the perfect climate for an already large Locust population to explode.
The Swarm
The population of the Locusts skyrocketed rapidly after the Cyclone had passed, just one month after the catastrophe the government were forced to change their status from alert to ‘plague’. There were now hundreds of Locust swarms, each numbering in their hundreds of millions, even billions of Insects, with analysis predicting that 50-60% of the country (over 290,000 km2 of 587,041 km2) had been engulfed by the infestation.
By late March the farmlands that over 13 million people in the country relied on for food were being ravaged at an unimaginable rate, at the peak of the plague the FOA (Food and Agriculture Organisation of the United Nations) estimated that roughly 500 Billion Locust were present on the island and were consuming vegetation at a rate of up to 100,000 tons of vegetation per day (the same weight as four Statue of Liberty’s to offer a random fact) and without international aid and investment there would likely be a death toll numbering in the thousands due to the ensuing famine, it was predicted that if left unchecked the Locusts would destroy over 60% of available crops.
The largest swarms covered areas of up to 30 km2, with each km2 containing 1 billion insects, the giant swarms were easily visible from great distances and resembled dark, rapidly moving storm clouds.
Whilst the Locusts impact on humans was easily observed, the Locust also predictably impacted numerous animal species across Madagascar in a negative manner. Particularly in species of Lemur that are iconic symbols of Madagascar, there are 10 critically endangered Lemur species on Madagascar and their survival hinges on the same food source that the Locusts were consuming. This meant failure to act at the time could very well have lead to multiple extinctions within the region.
Combatting the Swarm
A program was set in place at the beginning of March 2013 by the FOA, with the plan to carry out prevention tasks over a three-year period at a cost of $40Million, the main course of action involved the mass spreading of pesticides over huge areas of land to prevent swarms from gathering further momentum and size.
The FOA have however admitted that their job will likely be an ongoing one, though, they are not receiving the support that they need, and the chances of a relapse of the 2013 event have been cited as highly likely, the best time to act would be during the spring when populations of Locust predominantly consist of Insects that have not grown wings yet, as these populations are easier to target and more sensitive to the pesticide in use.
Looking to the Future
Extreme weather incidents are becoming increasingly common on our little blue ball, and it seems that this trend will likely only get worse before it gets better, as such I feel that more needs to be done to not only protect us, but also to protect all the animals in this world who are suffering through no fault of their own.
I find the whole topic of culling quite difficult to comprehend, even when the animal in question is a ravaging insect, I struggle enough to live feed our pet Bearded Dragon Locusts… So, the thought of destroying 400-500 Billion animals disturbs me to say the least, but on rare occasions I feel it can be justified to preserve the world we know and love.
Despite their deservedly bad reputation the Locusts have their place in this world and form an important part of the surrounding ecosystem, they may have even contributed to vital population control in the past, a trait that is not seen as desirable by us. They are resilient little animals though, and, I’m sure a plague the size of the one observed in Madagascar will occur again within our lifetime.
Content Sources
News Database for the Madagascan Locust swarm
Locust Biology
Resteemed by @resteembot! Good Luck!
Curious?
The @resteembot's introduction post
Get more from @resteembot with the #resteembotsentme initiative
Check out the great posts I already resteemed.
@originalworks
The @OriginalWorks bot has determined this post by @amavi to be original material and upvoted it!
To call @OriginalWorks, simply reply to any post with @originalworks or !originalworks in your message!
Your post are always so interesting. At one time I too think this was the earths way of controlling populations. Now that we prefer all creatures both man and animal to survive this termination can only be a temporary gain and will surely reoccur. Thank you for your post.