Saturday, June 13, 2015

The Myth of "Good Bugs" and "Bad Bugs"

Almost every insect identification request I receive includes the same question: "Is this a good bug or a bad bug?" Ok, another frequent question is "How do I get rid of it (them)?" The concept that any particular species of any organism is inherently good or bad is a symptom of collective ignorance, and I am not sure that the entomological community has done much to counteract that logic.

Caterpillars of the Cloudless Sulphur eat Senna. Can you live with that?

A good deal of our opinions and beliefs have been biased by large scale agriculture, and the fear-mongering media coverage of economic pests. You also have "organic" advocates who promote "beneficial" species, which they often have for sale in their nurseries and other businesses. The common denominator in those instances is money. Millions, if not billions, of dollars are at stake in products ranging from household and garden pesticides to bug zappers to laboratory-reared lacewings and parasitic wasps. Don't you know that you can't live without any of this stuff?

Get behind the sales pitch and the reality is much more subtle and variable. Take the praying mantis, for example. Here in the U.S. you can purchase the egg cases (ootheca) of the European Mantis, Mantis religiosa, for your garden, despite the fact that in most areas of the country you already have one if not several native species already there.

A native mantis eats a Queen butterfly

Then there is the idea that mantids are beneficial predators. Mantids are completely indiscriminate hunters. They will eat bees and butterflies as often as grasshoppers and caterpillars. There are even well-documented incidents of larger species killing hummingbirds. Mantids still looking wonderful to you now?

Phytophagous (plant-eating) insects, on the other hand, simply must be pests, right? If so, then how come so many species have been imported from overseas to control noxious weeds? Most herbivorous insects are highly "host specific," meaning they feed on only a few, closely-related plants. Those plants have learned to co-exist with the insects that eat them. The plants produce their own chemical defenses, and even "talk" to other nearby plants to warn them of an impending infestation. Native plants are better able to withstand an onslaught because they are growing in suitable soil and climate. This also allows them to quickly recover from even the most intense defoliation.

This leaf beetle was imported to control saltcedar (Tamarix spp.)

You can also not equate your garden, yard, or woodlot to a massive farm, orchard, or forest. The reason there are pests at all is because we insist on growing large scale monocultures of various crops (and I would include tree farms in that). What self-respecting European Corn Borer is going to turn up its nose (antennae?) at acres and acres of its host plant? We set the table and then complain about our uninvited guests.

The real world of nature does not play favorites, and if you want a healthy planet Earth, let alone a garden, yard, or home, then you have to stop thinking of every species as "good" or "bad." You don't have to like every creature. Personally, I don't like mantids, but I do recognize their place in the grand scheme of things, and appreciate their existence for that reason alone.

I heartily encourage a public attitude that embraces all life forms, treats them with respect, and actively cultivates a sustainable human culture in which we can all coexist....SLAP! Sorry, there was this mosquito....

13 comments:

  1. Another great article ..thank you.. Michelle

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  2. So well said! We need to keep presenting these arguments again and again until they begin to register. Recently, what fills me with frustration is the attitude of many monarch butterfly lovers: "Monarchs are good. Anything that eats milkweeds is bad. Worse yet, anything that eats monarchs is super-evil." So much for the monarch butterfly being a gateway to learning about conservation!

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  3. Hear, hear!

    I'm even learning to tolerate slugs. Within reason.

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    1. Nice! I totally understand the slug thing. Not my favorites, either.

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  4. Excellent, Eric! Now if only i could make more headway with people's fear and loathing of spiders. In my classroom, no one is permitted to kill any insect/spider they find. I keep a couple of jars handy to catch them and take them outside. When they see an "older" woman with a jar catch them and study them without fear, I hope it makes some kind of impression.

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    1. Thank you for the compliment, Lisa....And yes, I think setting an example is the best thing anyone can do. Keep up the great work!

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  5. All that is so true and can't be said often enough. I hope it reaches the right ears and eyes. I often feel that we are preaching to the choir. But after I was a member of a gardening group for a while, where I was battling the goody - baddy attitude every day, I left. I felt that I could have done a lot to enlighten at least a few members, but I just could not take human self-centeredness and greed in such high doses any longer

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    1. I can certainly appreciate that situation. I'm facing the same thing with a Facebook group a good friend added me to. I've been on vacation for a week, so maybe I can face them with renewed enthusiasm now....

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  6. I think bugs always cause problems
    So it must always looking for solutions to this

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  7. Thats just dumb. As farmers some bugs are "good" for the crop and some are "bad". We arent talkimg nature here, its agriculture, and it is wut it is. Thats like saying "oh, cancer is natural, it helps keep the humanpopulation down, its niether good nor bad." cancer is bad. So are cyclamen mites.

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  8. Excellent and concise essay, Eric. I have shared the link to my regional bug group.
    And to those who wrote the previous two comments. Of course, you are right that certain insects and their kin are bad for human endeavors, and we must find good ways to deal with those problems. That, however, is not quite relevant to the point that Eric is making. Crop pests and disease vectors are bad in those contexts, but not inherently bad or evil.

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  9. It needed to be said, and is well said - and again, the answers show that you can preach to the choir who will agree and others will not get it. It's true though, agricultural mono-cultures and human bodies older than the span that humans evolved for are not 'natural' and can only be maintained by unnatural means. That does not make the bugs bad, does it? I think the group worth educating are pleasure gardeners. They are the ones using, per unit of ground, the most pesticides (more than farmers who have to do a cost-benefit calculation. These hobby gardeners are also asking the goody-baddy question most often. Maybe we can make THEM understand that most 'pests' only kill plants that the gardener tries to raise under unsuitable conditions. It's the gardener who plants exotics and disturbs the natural balance. The bugs just take advantage. Plant local wild flowers and trees, and watch with interest, but without judgement, the interaction that happens.

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