The Increase of Multi Legged Life in the World

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Issue 17, Volume 110

By Jenna Mackenroth 

In the large mess of 2020, an infestation of new issues has arrived, one of which is an unprecedented increase in the population of bugs. Two new invasive species in particular, the Asian murder hornet and the Hokkaido gypsy moth, have entered the United States, most likely via air cargo and shipments from East Asia. Due to their non-nativity, their arrival poses a large threat to the survival of native organisms and habitats. Similarly, India and parts of Western Africa are currently experiencing an infestation of desert locusts that are putting their crops and ecosystems at risk by devouring farms and habitats. The immediate importance of these infestations, such as famines and ecosystem disruption, are the easiest to tackle, but they are symptoms of the larger environmental trend of climate change and its devastating consequences.

Asian murder hornets, formally known as Vespa mandirinia, are native to the warm tropics of easter and southeastern Asia. They are the largest species of hornets in the world, with the the female murder hornet spreading an average of 2.2 inches (5.6 centimeters) long, and they are commonly found to prey on species of honey bees. In the United States and other regions of North America, the murder hornet poses a great to the already disturbingly sparse honeybee populations.

The hornets feed on the larvae of honeybees for sustenance. As they attack a nest, they release a chemical hormone that signals for other hornets to attack. Using their powerful mandibles, or the arthropod’s sideways-moving equivalent of a jaw, they decapitate the adults before feeding on the larvae. Japanese honeybees, which are commonly hunted down by the hornets, have developed a defense mechanism that involves surrounding the hornets and vibrating. In this self-defense mechanism, the honeybees use the vibrations to increase friction in the air, thus heating it up. As they continue to vibrate and generate heat, the hornets begin to heat up to an unbearable temperature. This temperate, which is 45.9 degrees Celsius (114.6 degree Farenheit) is just beyond the limits of the murder hornet, and thus, it kills them. In contrast, the American species of honeybee does not have this defense mechanism and is unusually vulnerable to the hornets. The already destabilized population of honeybees, which had finally started to improve after hard work by conservationists, is at prominent hazard.

The Hokkaido gypsy moths, which are known to defoliate countless trees and destroy forests, are also recently voracious visitors from Asia. Their larvae also destroy tree bark, further endangering the woods. Though they are most prevalent in Washington state, the Hokkaido gypsy moths may migrate and eventually begin destroying forests across the United States. A dense infestation of gypsy moths is able to defoliate 30-60 percent of a forest. Their efficiency in arboreal destruction has posed concerns about carbon emissions, and many believe that the destruction of forests and a large increase in Gypsy moth populations could set back reforestation efforts and release carbon emissions back into the atmosphere.

In India, an infestation of desert locusts has completely demolished crops in the states of Punjab, Madhya Pradesh, Maharashtra, Gujarat, Uttar Pradesh, and Chhattisgarh. This specific species of locusts, called Schistocerca gregaria, has been known to plague nations by demolishing crops, leading to large famines. According to the United Nations Food and Agriculture Organisation, 40 million locusts can eat as much food as 35,000 people. The desert locusts tend to fly along monsoon winds, which suit for their breeding pattern and migration. In addition to the wind patterns facilitating the travel and spread of locusts, unusually heavy rains allowed for denser growth of vegetation that the locusts could feed on. However, higher occurrences of monsoons have led to greater proliferation of the locusts and thus a greater fear of crop and environmental damage.

The increase in the population of these insects is a dangerous indicator of a much larger problem: climate change. Though the spread of such insects is attributed to shipping and transcontinental transport of goods, their survival is ensured by abnormally high temperatures and longer spring and summer periods. The population of these insects decreases due to colder temperatures; however, if they don’t die off, they enter a period of dormancy and stop breeding. Unfortunately, with the recent increase in temperatures caused by global warming, such dormancy periods have simply ceased to exist. Populations of these insects, especially locusts, have continued to proliferate to levels that destabilize ecosystems. As the temperatures fail to reach the necessary low to trigger dormancy, the cycle that previously existed and kept numbers under control has disappeared. In turn, the elevated population causes a change in ecosystems that other native organisms and species cannot keep up with.

Though Asian honey bees have a clear-cut way of defending themselves against hornets, American honeybees do not have one against this kind of predator because it is not native to their natural habitat. A decrease in honeybee populations is devastating to North American ecosystems, as honeybees are one of their primary pollinators. Similarly, the ability of gypsy moths to rapidly defoliate entire forests has led to concerns about their effect on habitats and carbon emissions. We currently depend on our forests to offset 15 percent of our carbon emissions, and the defoliation and tree death caused by gypsy moths could potentially release these emissions back into our atmosphere.

The locusts currently invading India and parts of Western Africa have introduced another environmental issue. People are so unequipped to fight such large numbers of harmful insects because the occurrence and degree of these infestations were unprecedented. Though farmers have the resources to combat “scheduled” seasonal infestation patterns, they have yet to adapt to mass infestations like that of the desert locusts. Because of this, they have resorted to using harmful pesticides against the locusts. However, this plan has deeply negative consequences; the most commonly used pesticide in question is a kind of organophosphate, which is deeply toxic and creates severe environmental damage. Many of the organophosphates are nerve agents and can reach and pollute water sources very quickly. In turn, they can harm other organisms, including farmers, near the site where the pesticide was sprayed.

The consequences of these infestations may seem geographically far from home, but the effects are surprisingly important to us. Honeybees are primary pollinators; they allow for the fertilization of flowers and crops that often end up on our plates and ultimately, in our stomachs. Honeybees are responsible for approximately $30 billion in global crops alone, and a dwindling population directly threatens both the revenue earned from crops—and whether or not we actually get to enjoy them. If the population of murder hornets increases, the risk of our already fragile honeybee population becoming even more unstable rises. Not only would this affect our crops, but also ecosystems and other animals which rely on plants pollinated by honeybees. As honeybees die out, certain plant species would follow, and after that, the animals; it’s a ripple that can turn into a devastating ecosystemic tidal wave.

The unprecedented presence of murder hornets is a clear sign of the unpredictable outcomes related to climate change. It is also a frightening wake-up call showing how sorely unprepared we are to face them. When considering our environmental actions, such as opting for non-environmentally friendly energy, we must remember that they have much greater consequences than just an increase in emissions. The increase in carbon release contributes to a greater issue of the negative impacts on ecosystems. Our actions could potentially cause mass famine and the extinction of several key species. The unexpected arrival and increase of the Asian murder hornet, Hokkaido gypsy moth, and desert locust serve to remind us of how our output affects the greater environment is essential.