26
May
Study Shows 50% Decline in Butterfly Population Across the European Union, 1990-2011
(Beyond Pesticides, May 26, 2023)The use of pesticides in agriculture, transportation, and domestic settings has created a disastrous conflict for the human species. Two irreconcilable facts confront humans as they try to adapt to the consequences of earlier choices: One, industrial civilization came to believe that because some insects, fungi, and other organisms like to eat the same plants humans eat, humans can kill them with impunity; two, because some insects and other organisms are necessary to the health and reproduction of plants, humans need to protect them. At no point in history have people acknowledged that it is very difficult to kill the “bad” actors while protecting the “good” ones. There are not really two sides to the biological fact; rather, pesticides and biodiversity meet each other on a single plane, like a Möbius strip.
Among the most dire effects of pesticides are their ruination of pollinators. Bees spring to mind as our primary pollinators, but they are by no means the only ones. Butterflies, often regarded as mere ornamental additions to a landscape, are actually significant pollinators themselves. Monarchs pollinate many flowers, including calendula and yarrow. Other butterflies pollinate dill, celery, fennel, cilantro, lettuce, peas, and basil, among other important food plants. Butterflies are also known to be excellent indicators of ecosystem health, so if an environment has lots of butterflies it is reasonably robust.
The European Union has just released a report, the European Grassland Butterfly Indicator 1990-2020 as part of the EU’s attempt to “halt the loss of biodiversity and the degradation of ecosystem services in the EU…and restore them, in so far as feasible, while stepping up the EU contribution to averting global biodiversity loss.” The Grassland Butterfly Indicator is one of the EU’s tools to identify trends in “genetic, species and ecosystem/landscape diversity.” The survey includes counts of 17 species of butterflies from 19 countries. Results show that, “Grassland butterflies have undergone a huge overall decrease in numbers. Their populations declined by almost 50% from 1990 to 2011” across the EU member states. This is derived from the Indicator, which has declined by 32% over the last decade. Intensification of farming is the major culprit for grassland butterflies, and climate, especially heat waves and drought, is close behind. Industrial farming not only destroys habitat, but it uses poisonous chemicals as well.
In addition to documented declines in Europe, research documents declines of 58 percent between 2000 and 2009 in the U.K. and of 33% over 1996–2016 in the state of Ohio in the U.S. Even steeper declines have been documented for Monarch butterflies, with an 80 percent decline of Eastern monarchs and 99 percent decline of Western monarchs.
Butterflies and moths belong to the order Lepidoptera. Unfortunately, some 70 percent of agricultural pests—many of them moths at various life stages—also belong to this order. This puts butterflies smack in the bullseye for many pesticides. As Beyond Pesticides has repeatedly reported, the neonicotinoid pesticides destroy insects’ nervous systems, and they are not picky as to species. Their effects on bees caused the EU to ban three neonicotinoids in 2013—clothianidin, thiamethoxam and imidacloprid—but in the US the Environmental Protection Agency is just getting around to pondering whether they are harmful enough to ban.
Until the last few years, the U.S. Environmental Protection Agency (EPA) had never considered a pesticide’s effects on endangered species in its registration process. In 2019 the Center for Food Safety sued the EPA, and a California federal judge ruled that “EPA had unlawfully issued 59 pesticide registrations between 2007 and 2012 for a wide variety of agricultural, landscaping and ornamental uses,” according to the CFS.
Last year the EPA admitted in response to that ruling that these three neonicotinoid pesticides are “likely to adversely affect from two-thirds to over three-fourths of America’s endangered species—1,225 to 1,445 species in all,” including many butterfly species. On May 5 of this year, EPA released new analyses of these neonics’ effects on endangered species. These more fine-grained analyses focuses on the species most at risk of extinction, and the results represent a “five-alarm fire,” according to the Center for Biological Diversity’s environmental health director, Lori Ann Bird. EPA identifies 25 insect species and upwards of 160 plants dependent on insect pollination whose existence is most perilous. This step by EPA is one in a long line of glacial movements that may result, if the winds of fate do not reverse, in the removal of these chemicals from the market.
Clothianidin is used on cotton, but cotton growers may be shooting themselves in the foot by using it. In 2021, Science reported on a study of cotton pollination showing that the services of butterflies and hoverflies add approximately $120 million annually to the $1.8 billion cotton industry in Texas. They do this by visiting different cotton flowers and appearing at different times than bees do. The researchers counted 40 bee species, 16 fly species, and 18 butterfly species in the cotton fields they examined. The study estimates that about 50% more flowers are visited by all pollinators than if bees were the sole actors. More broadly, according to the Center for Regenerative Agriculture and Resilient Systems at California State University Chico, the efforts of wild native bees and other pollinators are worth $3 billion.
Change at the federal level is too slow, according to advocates, but many efforts at smaller scales, from scientists to farmers to individual citizens, are afoot. Butterflies may have been left out of much consideration of the pollinator crisis and development of ways to assess ecosystem health in general, but they are great poster children for both problems. They are what might be called “charismatic minifauna”—beautiful and beloved by people all over the world. In the U.S., many citizens participate in butterfly counts every year, organized by the North American Butterfly Association. These can be very helpful to researchers trying to assess how quickly our ecosystems are collapsing. Home gardeners can help pollinators in many ways, but one caveat: Milkweed, the mainstay of monarch support, may contain pesticide residues that harm monarch caterpillars if the milkweed plants come from a nursery. Some caterpillars do eat foods humans like, but most of these are moth larvae, and the damage butterflies may cause is surely outweighed by their insects’ benefits.
There are also moves to modify farming practices. As Beyond Pesticides has noted, hedgerows are a good way to help many species of native pollinators. Hedgerows of small trees, low shrubs and native plants provide refuges for these insects and can also help control pesticide drift across field boundaries.
In Oregon’s Willamette Valley, vineyards are starting to incorporate pollinator habitat between their rows of vines. Buzz Cover Crop Seeds of Philomath, Oregon sells seed packets for pollinator-friendly field cover crops and pathways between grapevine rows that have multiple benefits and help reduce chemical applications. Oregon also offers a “pollinator paradise” license plate, the fees for which support pollinator research at Oregon State University.
Some state and federal transportation agencies are acting. The Federal Highway Administration and numerous state departments are incorporating pollinator-friendly policies. The FHA publishes a handbook, “Roadside Best Management Practices that Benefit Pollinators.” Even airports, some of the most habitat-destroying and contaminated lands in the world, may be changing: the National Academy of Sciences has published a report, “Considerations for Establishing and Maintaining Successful Pollinator Programs on Airports.”
The pollinator crisis makes it clear that the template for sustainable human life must change. The toxic Möbius strip of pesticide use versus biodiversity must be broken and reassembled to promote the smooth flow of life. Without drastic reduction in the creation and use of pesticides, the plant and animal systems we need to survive will collapse. It is not enough to preserve European honey bees and not the plethora of other volunteer pollinators that exist all over the world. We must practice “what’s good for the bee is good for the butterfly” agriculture without delay. See all the reasons to support organic agriculture on Beyond Pesticides’ Keeping Organic Strong webpage.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: European Grassland Butterfly Indicator, Science Daily
