Friday night, at my niece’s birthday party, the conversation turned (not started by me … surprisingly) to news from Germany: the insects are disappearing.
abundance of flying insects has plunged by three-quarters over the past 25 years
In this serious study (peer-reviewed publication: More than 75 percent decline over 27 years in total flying insect biomass in protected areas), that involved surveys from across German nature reserves and natural areas, the pattern is pretty much consistent: numbers and mass of flying insects have shown a precipitous decline.
This is a survey work without a definitive ‘why’ statement (Scientific Theory). Like with bees, hypotheses as to why the insects are disappearing with varying degrees of substance but no certainty as to why.
cause of the huge decline is as yet unclear, although the destruction of wild areas and widespread use of pesticides are the most likely factors and climate change may play a role. The scientists were able to rule out weather and changes to landscape in the reserves as causes, but data on pesticide levels has not been collected.
Truly — we don’t know “why” but we do know it is occurring, that insects are disappearing.
This is Germany, one might suggest, and somewhere — someone — might be thinking/suggesting that this is somehow a German phenomena (looking at the timeline, German unification kills insects as hypothesis?) but there is global work showing declines in insects. From the article:
Current data suggest an overall pattern of decline in insect diversity and abundance. For example, populations of European grassland butterflies are estimated to have declined by 50% in abundance between 1990 and 2011.
Going back to that birthday party conversation, illuminating ‘bringing it to personal life’ comments included this observation for any/all that does long-distance driving:
I used to have to stop, multiple times, to clean the car windshield of dead insects when driving to Cleveland to visit my family. Now, I can go there and back and there might not be a single bug ...
That sparked me to thinking … having gone to school in the Midwest (too many) decades ago, those drives would eat up windshield wiper fluid and the car’s grill would be filthy at the end of the drive. Driving my eldest to school in the Midwest (with detour to Kentucky for the eclipse ...) this August, in what one might consider to be peak insect season, I did not have to clean the windshield of insects once during the entire trip and, thinking back, I don’t recall having to clean any insect remains from the car at the end of the trip.
From decades-long (amateur) scientific data gathering to the car’s windshield, the ominous situation seems clear: insects are disappearing.
Should we care?
Sunday evening, at a dinner party, a friend sparked a conversation starting with ‘I hate mosquitoes … this is an insect that shouldn’t exit ...’ If we think of that in terms of the disappearing insects, sort of like the people who react to a record-breaking warm day in January with ‘if this is global warming, give me more of it’, many people see flying insects as pests to detest and likely would welcome hearing that they’re disappearing. (NOTE: that is not that friend — whose comment really was more focused & even nuanced ...)
But, flying insects aren’t some abstraction, some ‘other’ irrelevant for ecosystem health and, fundamentally, human existence. From the article’s introduction,
insects play a central role in a variety of processes, including pollination [1, 2], herbivory and detrivory [3, 4], nutrient cycling [4] and providing a food source for higher trophic levels such as birds, mammals and amphibians. For example, 80% of wild plants are estimated to depend on insects for pollination [2], while 60% of birds rely on insects as a food source [5]. The ecosystem services provided by wild insects have been estimated at $57 billion annually in the USA [6].
And …
Gastronomy implications
Now, another portion of last evening’s dinner conversation (with various degrees of disgust … though not from me) was the growing move to commercialize human food from insects (or entomophagy … by the way, some restaurant options for exploring insect-based cuisine). Taking us back to another reason to think about and be concerned about disappearing insects.