The good weather, the long days and the refreshing bathing on beaches and in swimming pools make summer the most anticipated season of the year. But summer is also accompanied by other less desirable visitors, such as wasps, jellyfish, cockroaches and mosquitoes.
Despite their bad reputation, these species are essential for the balance of ecosystems and for protecting us from pests, and some of them even have biomedical applications. Their disappearance would have catastrophic repercussions for the planet’s biodiversity.
Wasps regulate other insects
If there is one omnipresent insect around swimming pools, barbecues and any pleasant activity we do outdoors, it’s the wasp. Their annoying stings have led to some very bad press, a label that does not correspond to the key function they perform in terrestrial ecosystems.
“We don’t know what would happen if wasps disappeared, but we would certainly see a huge explosion in the populations of the insects they prey on, such as aphids, caterpillars…” says Seirian Sumner, a professor at the Centre for Research on Biodiversity and the Environment of University College London (United Kingdom) to OpenMind.
About 110,000 species of wasps have been identified and an estimated 100,000 more have not yet been discovered. As Sumner notes in an article published in The Conversation, these insects are at the top of the invertebrate food chain, hence their role as regulators of other populations is imperative.
They also act as pollinators of plants, transporting the pollen so that the production of seeds and fruits is possible. In addition, the potential of their venom to kill cancer cells without harming healthy ones is being investigated, specifically the mechanism of an antibacterial peptide of the Polybia Paulista wasp.
Jellyfish are also not well received on the beaches. Their simple presence can cause panic among bathers, who fear the painful stings that contact with their tentacles can deliver. But these gelatinous animals are important for the marine life cycle. They serve to transfer organic particles rich in carbon from the surface to the depths.
In the biomedical field, the Portuguese caravel (Physalia Physalis)—which is not really a jellyfish but a colonial hydrozoan—was key to understanding the basis of anaphylaxis, a type of potentially deadly allergic reaction whose discovery was recognised with the Nobel Prize in Medicine in 1913.
The green fluorescent protein of the crystal jelly (Aequorea victoria) is a luminescent marker widely used in cell research, medical diagnosis and in different treatments, for which the 2008 Nobel Prize in Chemistry was awarded.
What if they disappeared from the seas? “Jellyfish, like birds, are very diverse and have numerous roles in the ecosystem. Undoubtedly their disappearance would have huge ramifications in many different ways,” Monty Graham, director of The University of Southern Mississippi’s School of Ocean Science and Technology, tells OpenMind.
The researcher leads a study in which he analyses the relationship between human well-being and jellyfish. While the jellyfish may be a well-known creature, the authors complain about the lack of research on its impacts, both positive and negative.
The Iron Genes of Cockroaches
Warm temperatures, humidity and darkness form the perfect cocktail for one of the animals least loved by humanity: cockroaches. Around 4,600 species have been identified worldwide, according to the Cockroach Species Archive.
The analysis of the American genome (Periplaneta americana), recently published in the journal Nature Communications, has revealed that their genes explain in part why they adapt so well to living in urban environments.
Some gene families associated with the response to chemical stimuli and with tolerance to chemical and biological factors have expanded remarkably, which may explain their resistance to certain insecticides.
Their role in the food chain is fundamental, as they feed on decaying organic matter, bedbugs and pest eggs. Cockroaches, in turn, are a source of food for certain arthropods, birds and rats.
They also release nitrogen, so they play a key role in the cycle of this element. As in the case of other species, their disappearance would lead to a chain of unpredictable ecological consequences, affecting both the anterior and posterior links of the food chain.
Mosquitoes protect the jungles
Beyond the annoying bites of persistent mosquitoes at dusk, what most worries doctors and researchers is their role as disease transmitters. Some of the most serious transmitted by these bites are the Zika virus, dengue and malaria.
But not all mosquitoes are so harmful. Under this umbrella are included more than 3,500 species that live on all continents, except Antarctica. Fewer than 100 of them transmit diseases to humans and it’s only the females that do it, as Nora Besansky, a biologist at the University of Notre Dame in the United States, explains in an interview with NPR.
Among the benefits to the ecosystem, the biologist emphasises that mosquitoes are an important source of food for fish, birds and other insects. In addition, as with wasps, they also have a pollinating function. Their total eradication would unbalance the food chain.
According to the scientific writer David Quammen, almost virgin ecosystems such as rainforests, where the house-building fever of humans has not arrived, are daunting places for humans to live thanks to the protection offered by clouds of mosquitos. There is nothing like mosquitoes to put the brakes on urbanisation.