I read a very disturbing story in Science magazine this month. A German amateur scientific group, the Krefeld Entomological Society, has conducted surveys of insect populations since 1989. These surveys show that the total mass of flying insects collected has declined by almost 80% in this time. Though the story in the May 10 issue of Science (Where Have All the Insects Gone?) does not make an assertion as to the cause for the decline, or whether the decline is limited to the European sites monitored by this society, they do mention the windshield effect. That is, are drivers encountering fewer bugs as they drive in the summer months, and is that symptomatic of a decline in insect populations?
If the monitored decline is widespread, then what does that say about potential effects on wildlife populations and diversity? At this time of year, we are very aware of the insect population, especially as we watch parent birds deliver squirming loads of protein to the next bird generation. If flying insects are in decline, then it indicates a decline in overall insect populations, and that has to be harmful to the species that live off of the abundance of insects in the warmer months.
The story does go into potential causes of the decline in population. Habitat loss in particular is mentioned as a potential contributing factor. But the story implies that a class of pesticides already identified as a factor in bee colony collapse, may also be contributing to the observed flying insect population declines. Neonicotinoid pesticides were developed in the 1980’s and were used for seed coatings beginning in the 1990’s. These pesticides have extremely low mammalian toxicity. But they are mobile in the environment, and are water soluble. Studies have shown that wildflowers adjacent to crop plantings can have concentrations of neonicotinoids higher than on the crop plants.
So this clearly is an issue that requires swift study, and if studies indicate it is justified, then it necessitates new regulations for this class of pesticide. Now let me state something from a personal perspective. I worked for a company that manufactures both herbicides and pesticides. For a good part of my career, the Ag Products division was my work home. I believe that agricultural chemicals provide benefits that outweigh their risks to the environment. I am not one who is chemophobic. And herbicides and pesticides are already among the most heavily regulated chemicals ever manufactured. But occasionally, a class of compounds is commercialized, only to discover decades later that there were unintended harmful consequences to non-target species. This happened with the chlorinated hydrocarbons like DDT. They had low direct mammalian toxicity, but when they accumulated in animals, they caused reproductive harm.
Another series of articles in Science recently discussed the ongoing extinctions that are occurring in the new anthropocene era. The anthropocene is the new geologic era defined by the effects that humanity is causing to our planet, and is now officially recognized by scientists. One of the points of the articles was that the inter-relationships between species are complex, and it is difficult to predict the effects on the system as a whole if one of the pieces disappears (becomes extinct).
What this means is as humanity continues to impose its will on the earth, resulting in the extinction of more and more species, the unexpected effects will continue to grow. At some point, a step-change in the system will show up, and suddenly a large portion of the ecosystem will not work. Bee colonies are a good example of this. Humanity is reliant on bees serving as pollinators for a wide variety of foods. So if we continue to use insecticides that harm bee colonies, then sometime soon we will not have many of our fruits and nuts and oil seeds available as our food sources. We are all related in life on this earth, and we are not immune to the ills of the ecosystem as a whole.
Unfortunately, within the US, the ruling political class has grown hostile to considering the health of natural systems as one of the inputs to making laws or regulations. Since flying insects do not contribute to dark money PACS, they have no advocate in the US Congress or in the administration. Instead, there are efforts to roll back science-based regulations within the EPA. Already the EPA has put a hold on a recommendation from a science advisory committee within the EPA that would have banned the use of the insecticide chlorpyrifos. See, with this administration, money and economic growth are the only things worth considering. All of this science stuff, well, how much money is donated to politician’s campaigns from scientists anyway? Not nearly as much as from chemical companies. So who should we listen to? Those who say that there is statistical correlation (though not proven causation) between exposure to a class of pesticides, and children with increased frequency of ADHD? Or those who donate?
Simplistic thinking breeds simplistic solutions. The natural world though, is complex, and is shaded not in black and white, but in a rainbow of bright hues. When you have an administration that looks at a problem solely in economic terms, and views regulations as barriers to economic growth, then you will develop solutions that cause great harm to the natural systems we rely upon. At some point, the hubris of the human race will cause us to be dashed against the rocks of reality as nature has its way. If only we can recognize our folly and act to reverse it before it determines our fate!