Insects aren’t cute or cuddly. It’s unlikely there will ever be insect-watching tours or “save the flies” T-shirts. While photogenic mammals are the poster children for tragic biodiversity loss, insects are also in an alarming worldwide decline.
And it’s not only bees. Many other types of insects are dying which are essential to the pollination of food crops and flowers, decomposition of biomass, nutrient turnover, and biological pest control.1
A groundbreaking study by a team of amateur German entomologists last year showed three-quarters of flying insect biomass across German nature reserves has disappeared in under three decades.2 Although there is consensus among entomologists that insects are in trouble,3 the study results produced audible gasps when they were presented – scientists did not expect such dire declines.4
The situation in Canada may be similar. Ask yourself: when was the last time the front of your car was really spattered with dead bugs after a country drive?
To date, most evidence of insect decline in Canada has been anecdotal: people simply noticing fewer bugs.5 Other relevant research is not on insect populations, but on the subsequent decline in birds that depend on insects as food. Many species of bug-eating birds in Canada have seen populations decimated.6,7
Neville Winchester, an adjunct associate professor at the University of Victoria, is launching an insect inventory study this summer in the municipality of Metchosin, near Victoria.8 The study is the first of its kind in BC, and important to understanding insect declines.
Winchester said he has noticed declines in bees and butterflies even on pristine properties. “So how do we quantify that? Well, that’s what we’re trying to do with this project.”
While bee deaths get the lion’s share of press, neonicotinoids indiscriminately kill other invertebrates such as worms, aquatic insects, and butterflies and moths.
Like the German study, Winchester’s project will use malaise traps to collect flying insects year after year at the same locations. Malaise traps look like three-sided mesh tents, with a funnel at the top to herd insects into a collection area. The biomass collected will provide data to track the health of future insect populations.
Because it will take many years to spot long-term trends, Winchester anticipates the study running almost indefinitely. He hopes a hundred years from now scientists will ask “who had the foresight to get this data?”
Winchester chose Metchosin because many residents are interested in environmental conservation, and because it gave him an opportunity to collect insects from the coastline to the highest altitudes in the municipality. Trained citizen-scientist volunteers will be tasked with servicing traps.9
“I’m glad Neville’s doing this project, more of these things need to be done,” said Jeff Skevington, a research scientist at the Canadian National Collection of Insects, Arachnids, and Nematodes. “We’ve known for a long time that there’s been significant declines, but quantifying it has always been the problem.”
Silent Spring Part II
Several causes of insect decline are likely. Habitat loss and urbanization, monoculture farming, climate change, and pesticide use are all factors.10 Of these, climate change is increasingly diminishing biodiversity as a whole, and is expected to rival land-use change, currently the largest cause, by 2050.11,12
One wildcard variable is vehicle strikes, which according to a Canadian study, could account for hundreds of billions of dead bugs every summer in North America.13
“It should be no surprise to anyone that insects have declined, because we’re pouring poisons onto the environment to try to get rid of insects in agricultural ecosystems.”
Entomologists seem to agree that insecticides, particularly neonicotinoids, are a sizeable part of the problem.14 Neonicotinoids are widely used to coat crop seeds and as an insecticide spray. They are water soluble, and 90% or more of the active ingredient leaves the plant and ends up in the soil or water. Some neonicotinoids are 5,000 to 10,000 times more toxic than DDT.15 While bee deaths get the lion’s share of press, neonicotinoids indiscriminately kill other invertebrates such as worms, aquatic insects, and butterflies and moths.16,17
“It should be no surprise to anyone that insects have declined, because we’re pouring poisons onto the environment to try to get rid of insects in agricultural ecosystems,” says Skevington. “Of course they’re going to have spillover effects.”
Bee part of the solution
To promote healthy insect populations, Skevington says communities need to ensure adequate green areas and corridors for insects to thrive. Winchester encourages people to join an environmental organization with initiatives related to preserving and enhancing insect habitats.
Around the house, the obvious thing to do is swear off pesticides. Skevington also advises planting native species in yards and gardens. “If people plant non-natives, you can have very nice looking habitat that’s devoid of life.”
Insect decline, though disturbing in its own right, is part of overall biodiversity loss – the death of the essential variety of life forms on earth. A new report by the preeminent science body on biodiversity warns biodiversity loss is “significantly reducing nature’s capacity to contribute to people’s well-being. This alarming trend endangers economies, livelihoods, food security and the quality of life of people everywhere.”18
Maybe a “save the flies” T-shirt isn’t such a bad idea.
Gavin MacRae is a writer suffering mild eco-anxiety as a side effect of recent fatherhood. He lives in Port Moody.
- Neville Winchester interview
- Hallmann CA, Sorg M, Jongejans E, Siepel H, Hofland N, Schwan H, et al. (2017) More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLoS ONE 12(10): e0185809.
- Jeff Skevington interview
- Neville Winchester interview
- Bird studies Canada
- Smith AC, Hudson M-AR, Downes CM, Francis CM (2015), Change Points in the Population Trends of Aerial-Insectivorous Birds in North America: Synchronized in Time across Species and Regions. PLoS ONE 10(7): e0130768.
- Neville Winchester, Research proposal, Temperate Rainforest Biodiversity – 2018-2022. Estimating species diversity and biomass trends in the Metchosin Igneous Complex in southwestern British Columbia, Canada: Biodiversity research and conservation in a rural municipality.
- Email follow-up questions for Neville Winchester
- IPBES (2016): IPBES (2018): Summary for policymakers of the assessment report of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services on pollinators, pollination and food production. S.G. Potts, V. L. Imperatriz-Fonseca, H. T. Ngo, J. C. Biesmeijer, T. D. Breeze, L. V. Dicks, L. A. Garibaldi, R. Hill, J. Settele, A. J. Vanbergen, M. A. Aizen, S. A. Cunningham, C. Eardley, B. M. Freitas, N. Gallai, P. G. Kevan, A. Kovács-Hostyánszki, P. K. Kwapong, J. Li, X. Li, D. J. Martins, G. Nates-Parra, J. S. Pettis, R. Rader, and B. F. Viana (eds.). Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, Bonn, Germany. 36 pages.
- IPBES (2018): Summary for policymakers of the regional assessment report on biodiversity and ecosystem services for the Americas of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. J. Rice, C.S. Seixas, M.E. Zaccagnini, M. Bedoya-Gaitán, N. Valderrama, C.B. Anderson, M.T.K. Arroyo, M. Bustamante, J. Cavender-Bares, A. Diaz-de-Leon, S. Fennessy
- Scientific American, March 28, 2018
- Baxter-Gilbert JH, Riley JL, Neufeld CJH, Litzgus JD, Lesbarrères D. Road mortality potentially responsible for billions of pollinating insect deaths annually. Journal of Insect Conservation. 19: 1029-1035. DOI: 10.1007/s10841-015-9808-z
- Email exchange with Jeff Skevington
- The Task Force on Systemic Pesticides
- The Environmental Risks of Neonicotinoid Pesticides: a review of the evidence post-2013 | Thomas Wood and Dave Goulson, Sussex University, authors
- Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Media Release | Summaries for Policymakers of all four assessment reports (Africa, the Americas, Asia-Pacific and Europe & Central Asia)