The Silence of the Bugs

The Silence of the BugsA recent study in Germany found a surprising decline in insects that cannot be easily explained.

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A study published last fall documented a 76 percent decline in the total seasonal biomass of flying insects netted at 63 locations in Germany over the last three decades. Losses in midsummer, when these insects are most numerous, exceeded 80 percent.

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This alarming discovery, made by mostly amateur naturalists who make up the volunteer-run Entomological Society Krefeld, raised an obvious question: Was this happening elsewhere? Unfortunately, that question is hard to answer because of another problem: a global decline of field naturalists who study these phenomena.

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In my own experience in the field I have not noticed a decline, but then that hasn't been something I was specifically paying attention to. I expect it to be a major topic of discussion at the meetings I'm attending this summer and the next few years it will provide grad students with potential research topics.Generally, bugs don't get much attention from the public. If anything, they are considered an irritant and the less of them the better, but without them not just agriculture would completely collapse, but so would every terrestrial ecosystem.

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The eminent biologist Edward O. Wilson, who has spent much of his life studying ants, has warned: If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos.

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Links and Information please.

I think it will turn out to be multiple human causes, but it will not be the same causes and at the same levels everywhere.I haven't read the study yet, so I don't know which specific insect orders were included. I suspect that some insect groups will be affected way more than others and that may give us our best clues about what is happening.My experience on my job was that certain groups of insect species have exploding populations and rapidly expanding ranges when they are introduced as exotic invasives. I do find it interesting and ironic that the pest insects seem to be the ones the evolve resistance to pesticides most readily, while the most beneficial insects perish. Both are the result of pesticide misuse and limited understanding of insect biology.There are fewer and fewer insect taxonomists being trained and less and less funding for research programs. Now we have a Republican controlled government that is stifling all science.

Some species of grasshoppers go through cycles of population booms where they build up over several years until there is a year with truly stunning numbers and then a period of years of decline. They have a huge impact on agriculture in the boom years.

This is true, although we have more knowledge about larger animals like wolves, bears, or big horned sheep and can make some predictions based on what we see where they still survive and where they have been eradicated.Most insect species have not been studied so we have little knowledge of their function within their ecosystem.Introduction of single species of insects can happen accidentally more easily with insects and can have devastating impact. Dendroctonus ponderosae, the Mountain Pine Beetle is causing heavy damage to forests throughout the Rocky Mountain region. Mountain Pine Beetle EpidemicThere are hundreds of species of bark beetles some which infect the trees with a fungus that is as deadly for the trees as the beetles themselves.Another species, Halyomorpha halys, the Brown Marmorated Stink Bug, attacks numerous fruits and vegetables and is very hard to control. Brown marmorated stink bugI worked on projects to study these species along with many others. In the case of Halymorpha we found several species of parasitoid wasps that may ultimately control them but we will probably never be able to eradicate them.

I have been lucky enough to see fireflies (actually a beetle). We don't have them in Oregon. Some of the places I go looking for dragonflies still seem to have lots of fireflies. One of the magical things about summer evenings.We are already seeing some insect species and plants they eat or pollinate get out of sync in their development. Climate change has caused plants to bloom when the pollinators adult stages have not yet emerged or adult insects are ready to lay eggs before their host plant is at a stage to provide food for larvae. What impact these changes will have for tens of thousands of species of insects and thousands of species of plants is completely unknown.The number of scientists qualified to study these things is rapidly dwindling and in the U. S. they are being forced out of the governmental agencies that have been historically tasked with protecting our forests and agriculture.

Cool, Libellula depressa. In general, dragonflies seem to be doing pretty well. Habitat destruction has the most negative impact on them. Chemical pesticides sprayed on aquatic areas can kill them, but one of the newer techniques using Bti for Mosquito Control is more directly targeting mosquitoes and does not affect the dragonfly nymphs even if they eat the mosquito larvae.