As we brace for a new bug season, I find myself hoping for a banner bug year.
Not for blackflies, mosquitoes, midges or wasps, but for dragonflies and their cousins, the damselflies.
A single dragonfly can eat anywhere from a couple of dozen to hundreds of mosquitoes
Every day, depending on what other insects are available. Unfortunately, they’ll also eat butterflies, which might leave them too stuffed to go after many mosquitoes.
Dragonflies not only help us by eating biting bugs, they are entertaining. They are fascinating to watch as their two sets of translucent wings allow them to fly straight up and down, upside down or backwards.
They are among the earth’s oldest critters, believed to have evolved roughly 300 million years ago. They were much different back then, much larger and probably more ferocious. Some dragonfly fossils have been found with wingspans of up to two feet.
There is some disturbing news about their future. A recent assessment from the International Union for Conservation of Nature (IUCN) says that about 1,000 of the roughly 6,000 known species of dragonflies and damselflies are at risk of extinction.
Of those, 95 are considered critically endangered.
These insects rely on wetlands, ponds and lakes for life, and pollution and climate change are making life difficult for them. So is destruction of wetlands, which humans tend to see as messy things that should be filled in to allow more development.
Now there is research indicating that winter road salt leaching into roadside storm ponds is harming dragonfly populations. Both dragonfly and mosquito larvae develop in these ponds.
Dragonfly larvae have huge appetites and one healthy dragonfly larvae can consume 11 mosquito larvae in just two hours. That’s a lot of mosquitoes that will not become biting adults that drive us crazy.
The research indicates that dragonfly larvae exposed to large amounts of road salt have smaller appetites, and develop into weaker, less healthy flying adults more susceptible to infections. As luck would have it, mosquito larvae do not suffer the same unhealthy results from road salt exposure.
That is interesting, helpful information and we are lucky to have it. Research on dragonflies is hard to come by because they have short lifespans, emerge as flying insects at different times in different places and are not easy to catch because of their nimble flight movements.
The ICUN said that there is not enough research data to determine the conservation status of more than 500 dragonfly species. Conservation status indicates whether a species still exists, or if it does, how likely it is that it will become extinct in the near future.
Dragonflies are not the only insects affected by changing weather patterns and human development. Research indicates that 40 per cent of insect species are declining and one-third are in danger of extinction.
Scientists who analysed 73 insect studies estimate that the world’s insect population is declining by 2.5 per cent a year and that in another 100 years insects could disappear completely.
Others say that is alarmist thinking and a world without insects is very unlikely. They say that reported declines are worrying but too little is known about insects to say anything definitive about their future.
In other words, we need to learn more about insects by devoting more effort and time to studying them.
Meanwhile, the bug season begins. While the scientists debate the future of bugs, the rest of us will continue to put up with them. Bring out the head nets and lotions, sprays and creams that are touted as the best stuff to keep them away.
As much as they irritate us, insects are critically important to the environment and all life on earth. No one should wish for their extinction.
It would be nice, however, to see fewer of the pesky types around and more of the good guys like dragonflies and damselflies.
Despite all the gloomy talk about the future of the good guys, there is hope. We are starting to appreciate the environmental value of wetlands and are doing more to protect them. And, there are enough smart folks around to figure out ways of preventing road salt from getting into their living rooms.
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