This study in protected and preserved areas of Germany is another alarm bell that is warning us that our environment has gotten too toxic even for the insects, birds, and butterflies. Much of the blame for this decline rests on agriculture’s shoulders. We are seeing these ecological declines all over the world–even in our treasured Green Mountain State.
We must finally realize that we have to change our food system from exploitative, pollutive, and abusive to regenerative organic.
This may initially seem like a good thing, but this occurrence, dubbed the “windshield phenomenon” by entomologists,1 is an ominous warning — a canary in the coalmine that the environment is in grave danger.
“I’m a very data-driven person,” Scott Black, executive director of the Xerces Society for Invertebrate Conservation in Portland, Oregon, told Science. “But it is a visceral reaction when you realize you don’t see that mess anymore.”2 It’s also not all in your head. Insects are vanishing right before our eyes, at a rate that’s at once sobering and alarming.
Seventy-Six Percent of Flying Insects Have Disappeared in the Last 27 Years
Declines in certain insect groups like bees, butterflies and even moths have been apparent for some time, according to researchers of a recent study published in PLOS One.3 However, their study looked at total flying insect biomass over a period of 27 years in 63 protected areas in Germany to assess the bigger picture. Using malaise traps, which are large, tent-like traps used for catching flying insects, the researchers set out to estimate trends in the number of flying insects in the region between 1989 and 2016.
A 76 percent decline was revealed, seasonally, while a midsummer decline of 82 percent in flying insect biomass was also recorded. The declines occurred regardless of habitat type and could not be explained solely by changes in weather, land use or varying habitat characteristics. The researchers noted:4
“Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services … This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning … ”
The ramifications of disappearing insects should not be taken lightly. It’s estimated that 80 percent of wild plants depend on insects for pollination, and 60 percent of birds depend on them for food. Further, the “ecosystem services” provided by insects as a whole is estimated at $57 billion annually in the U.S. alone, the researchers noted, so “[c]learly, preserving insect abundance and diversity should constitute a prime conservation priority.”5
While increasing attention has been given to declines in bees and butterflies, the data suggest that “it is not only the vulnerable species, but the flying insect community as a whole, that has been decimated over the last few decades.”
The researchers described the significant decline as “alarming,” made even more so because the traps were placed in nature preserves that are meant to protect ecosystem functioning and biodiversity. Still, nearly all (94 percent) of the protected areas included in the study were enclosed by agricultural areas, giving clues as to why so many insects may be disappearing.
‘Agricultural Intensification’ May Be Killing Off Insects at an Alarming Rate
After observing the massive decline in flying insects in under 30 years, the researchers then began looking into potential driving mechanisms. Landscape and climate changes were not strongly associated with the declines, according to their analysis, so they suggested other “large-scale factors,” like agricultural intensification, may be involved:6
“Agricultural intensification (e.g., pesticide usage, year-round tillage, increased use of fertilizers and frequency of agronomic measures) that we could not incorporate in our analyses, may form a plausible cause … Part of the explanation could therefore be that the protected areas (serving as insect sources) are affected and drained by the agricultural fields in the broader surroundings (serving as sinks or even as ecological traps).
Increased agricultural intensification may have aggravated this reduction in insect abundance in the protected areas over the last few decades … Agricultural intensification, including the disappearance of field margins and new crop protection methods has been associated with an overall decline of biodiversity in plants, insects, birds and other species in the current landscape.”
Indeed, while the observational study wasn’t set up to determine causes for the insect decline, the increasing use of agricultural chemicals is a prime suspect, one that’s been implicated in insect losses before. For instance, numbers of Monarch butterflies have decreased by 90 percent since 1996. As usage of glyphosate (the active ingredient in Monsanto’s Roundup herbicide) has skyrocketed, milkweed, which is the only plant on which the adult monarch will lay its eggs, has plummeted.
In 2013, it was estimated that just 1 percent of the common milkweed present in 1999 remained in corn and soybean fields and, tragically, while milkweed is not harmed by many herbicides, it is easily killed by glyphosate.7 A 2017 study published in the journal Ecography further noted a strong connection between large-scale Monarch deaths and glyphosate application.8,9
Neonicotinoid Pesticides Implicated in Bee, Butterfly and Predatory Insect Declines
Neonicotinoid pesticides, which are widely used in intensive agricultural operations, have been implicated in the decline of bees, particularly in commercially bred species like honeybees and bumblebees, although wild foraging bees may be negatively affected also.10 Neonicotinoids are the most widely used insecticides on the planet.
As systemic pesticides, the chemicals are typically applied to seeds before they’re planted, then taken up by plants as they grow, contaminating flowers, nectar and pollen. “Neonicotinoids are suspected to pose an unacceptable risk to bees, partly because of their systemic uptake in plants, and the European Union has therefore introduced a moratorium on three neonicotinoids as seed coatings in flowering crops that attract bees,” a study published in Nature revealed in 2015.11
Separate research published in the journal Nature also suggests that combined exposure to neonicotinoid pesticides and parasites may alter queen bees’ physiology and survival, thereby potentially destroying the whole hive.12 Butterflies are also being affected.
Researchers from the University of Nevada tracked 67 butterfly species at four locations for at least 20 years.13 At each site, declines in the number of butterfly species were most closely linked to increased used of neonicotinoids, even more so than other potential factors in butterfly declines, like land development.14
Applying the chemicals to plant seeds, rather than spraying them across a field, was supposed to reduce the effects on nontarget insects, but research published in PeerJ found both types of insecticides are equally damaging.15 The study revealed that the use of neonicotinoid insecticides in North American and European farming systems led to a 10 percent to 20 percent decline in predatory insects like tiger beetles, which is similar to those caused by “broadcast applications” of pyrethroid insecticides.
Like pollinators, predatory insects also have an important role in the ecosystem, contributing “billions of dollars a year to agriculture through the elimination of crop pest insects,” study author Margaret Douglas, postdoctoral researcher in entomology, Penn State, said in a news release.16
Another predatory insect, parasitoid wasps, are also at risk from the chemicals. Research revealed that exposure to just 1 nanogram of the neonicotinoid imidacloproid, while not enough to kill the insect, reduced mating rates by up to 80 percent, which is essentially the same thing on a specieswide level.17