Home Biologist salary Summer nights are no longer “a sound chaos”. Where have all the bugs gone?

Summer nights are no longer “a sound chaos”. Where have all the bugs gone?


As summer rolls around, I often think of my childhood in Maryland in the 1970s, and invariably, I think of fireflies. Most of the outdoor spaces in my neighborhood were tame spaces – mowed lawns and manicured gardens. Some, however, were left wild, and in the summer these wild spaces were teeming with vegetation.

Dark green vines of honeysuckle, shiny leaves of poison ivy, bright orange threads of the plant parasite known as dodder would drape over bushes and climb trees. And all that growth was an insect paradise. As evening fell and I looked across our back lawn towards the brush I could see a few flashes of fireflies and then as the sun crept away I saw so many more, twinkling and streaming against the darkening backdrop.

The fireflies were by no means alone. The flickering of their lights was accompanied by the chirping of crickets and the cries of locusts, a cacophony of insect sounds that mingled through the air in a unified hum. The noise betrayed to our ears the sheer number of insects that were there and in what amazing variety. The show these insects gave was the most punk rock performance I have ever seen. It started before sunset, lasted until dawn, obeyed no limits and followed no rules. The same heat and humidity that slowed the pace of our lives accelerated the insects. They pupated and emerged, some after years underground, in raucous celebration, voracious consumption and a race to breed.

The show these insects gave was the most punk rock performance I have ever seen.

Are summers full of sights and sounds of insects a thing of the past? Environmental experts have been measuring wild insect populations for decades. In recent years, the news has been dire. Writing in Current Biology in 2019, insect ecologist David Goulson cites studies from Germany and Puerto Rico that report staggering declines over the past quarter-century in total insect biomass and species diversity. In one such study, the total insect biomass collected from the wild by researchers in 2014 was less than a quarter of what it had been using the same methods at the same location in 1989.

Goulson points to several economic reasons why we should pay attention to insect decline. He notes, for example, that three-quarters of the types of crops we grow require insect pollination, “a service estimated at $235-577 billion per year worldwide.” It further appeals to our sense of natural wonder, asking: don’t all species have as much right to be here on the planet as we do?

Why does this happen? The proposed causes of insect decline are too easy to imagine. In a research paper published in the journal Nature in April this year, Outhwaite and his colleagues reported that insect decline is at its worst in places on the planet where large-scale agriculture and the impacts of climate change coincide. A glimpse of hope comes from the observation by Outhwaite and his colleagues that the presence of natural spaces near sites of low-intensity agricultural use – spaces similar to the wild patches that adjoin mowed lawns in my former neighborhood in Maryland, but on a much larger scale – mitigates declines compared to nearby sites without coverage.

Just before the monsoon season, these fireflies congregate in parts of India. This particular image is a stack of 32 images of this tree. (Prathamesh Ghadekar via AP)

The decline in insect populations is alarming. The problem is one symptom among many that we are not treating our planet as we should. As a nature-loving child who grew up to be a biologist studying an insect (the fruit fly Drosophila melanogaster), I find it a symptom of environmental distress that particularly resonates with me.

I believe that radical societal change on a global scale is needed to save us – along with fireflies, crickets, locusts and so many other invertebrate beasts – from environmental destruction and climate change. Yet I wonder when our society will bend to meet the need. And perhaps more importantly, I wonder when, as an individual, will I be ready to step in and do more, change more than my household recycling habits?

How quiet must summer nights get? How devoid of magical flashes of light? The chaos of sound? The noisy life of the little ones?

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