The History of Biocontrol and IPM

The Nature of Things

IPM is a fairly new term. So is biocontrol. Terminology aside, though, there is nothing new about the practices themselves. Predation and parasitism, being devised by the schemes of nature, have been around since the beginning of time. The food chain, as we call it, is how things work. It is one of the reasons certain things flourish while others pass into extinction. This is balance, as balance is not always indicated by like numbers on even footing. Perpetuation of life on earth, in general, is always the outcome — until it is meant to end. Not all life will survive, just that capable of holding its own through adaptation or evolution. Some pretty remarkable events have shaped the world we live in. Catastrophic events both natural and man-made. But life continues in one form or another. Popular opinion-or unpopular, depending on your view-now dictates that all things which currently live must continue to live as extinction is no longer acceptable. In part, due to the incomprehensible numbers of human beings in this world, this thinking is understandable. We are often thought of as the earth’s caretakers. Thought of this way, that is, by ourselves. We might be wrong, though. Maybe a higher power has considered us as we are, imperfections, stupidity and all — good or bad in our perception — as “normal.” Perhaps we are still dwelling within the original template of life on earth. After all, we are the brainy ones capable of so much destruction and so much cure, but it doesn’t necessarily mean we have the right or responsibility to change a thing. If a species cannot adapt or evolve, maybe it is meant that it is time for that species to pass. Then again, maybe not. I offer no answers, only insight and conjecture. I’m not even asking questions. It is within ourselves, perhaps, that the opinion of the truths herein lie. And, quite possibly, it all means nothing. Please excuse my digression if that’s what it is. Let’s get back to predation and parasitism-the food chain. Like I said, it is nothing new, all humans have done is to harness some of this natural phenomena.

Starting in China

In 16th century China, the earliest example of insect-based pest control I know of, biocontrol was being employed to combat agricultural pests. The facts are a bit shaky here, as is often the case with early recorded history as much of our contemporary beliefs are formed by the opinions of one person — the person telling or passing along the story. I believe the Chinese used predacious ants, Oncophylla smaradina, to thwart certain pests in citrus orchards. The ants were always there. So were the pests. All the Chinese did was to bridge together their valued trees with bamboo so the ants could gain the upper hand in the hunt for their quarry. This action allowed the ants to travel quickly throughout the orchard and to prosper while the pest numbers were being reduced to inconsequential numbers. The result: the trees were allowed to grow unhindered by excessive pest attack, resulting in better yields of fruit. Like I said before, I know little of the actual facts in this example. And I have taken liberties. I filled in the many of the blanks with common sense. More conjecture, perhaps.

More recently a history of insect biocontrol outside the Americas had taken place in 1762 when mynah birds were relocated from India to the islands nation of Mauritius for the control of locusts. This project, from what I understand, was successful. More importantly, perhaps, was the actual importation of the birds. This example details the first commercial shipment of insect biocontrols. I’ve been unable to determine if it was Fedex or UPS handled the shipment, but I did find out it went without a hitch.

Early in the US

Closer to home, and the facts here are surely a little more in focus, we had our first encounter with the world of human-harnessed biocontrol in the Americas. This was at the end of the 19th century. In 1883, millions of parasitic mini-wasps, Apanteles glomeratus, were released in California in an effort to control the imported cabbage worm, Pieris rapae. Though it sounded good at the time, it didn’t work. The idea that it would work was based on earlier (1602) but misguided observations by an Italian man named Aldrovandi who thought the immature parasitoids were caterpillar eggs (in 1700 he was corrected by Antoni van Leewenhoek who recognized the parasitism for what it really was). The project was a complete failure. The wasps simply did not take, though I’m not exactly sure as to why. The project was scrapped, but not entirely forgotten. It couldn’t be forgotten. People were trying to grow plants for food. As pests, even then, were a real pain in the rear and interfered greatly with the burgeoning need for more and more agricultural commodities. This transpired before chemicals were introduced, so, through necessity and desperation, research continued in this field.

Later in the US

Cottony Cushion Scale (1) Six years later, in 1889, another likely but experimental operation was put into effect by the United States Department of Agriculture, USDA. This time their ducks were in a row and, through their research, a scenario which was more likely to succeed was implemented. The pest this time was the cottony-cushion scale, Icerya purchasi. It was decimating the California citrus industry. A natural enemy to this pest was identified and located in Australia. The answer, they thought, was embodied in a little critter called the vedalia lady beetle, Rodolia cardinalis. Thousands were imported-but few survived the journey. Fedex and UPS were a lot slower back then. In fact, only about five-hundred beetles were alive and able to be released into the citrus crop. The beetles, fortunately, like, totally loved the laid-back Californian climate, you know, and, like, survived, like, totally.

Cottony Cushion Scale (2) In fact, they thrived. The warm sunshine and abundant food (the scale insects) allowed them to gain a real foothold and overtake the pests within weeks. The operation was a huge success and the vedalia lady beetle, then called the “miracle bug” was credited with saving the California citrus industry from certain demise. This control lasted for decades as the beetles thrived. As a footnote, though, chemical technology has since all but wiped out the beetles. As a result, the cottony-cushion scale is now again a pest in need of control. The chemicals which displaced the need for the beetles are no longer effective. And to those chemicals the scale insects have become resistant. If not for other pests in need of chemical controls which, by the way, are incompatible with the beetles, the vedalia ladybugs could once again be introduced and would, again, probably prosper. One step forward, two steps back. See how much smarter we, as human beings, are now.

Rachel Carson and Others

Rachel Carson - A few decades later, in the 1950s, chemicals were introduced by some really happy-go-lucky scientists, biocontrol technology took a nose-dive and we were duped into believing progress was being made. A few individuals, though, did not give up hope. They saw the future with clearer eyes than many. Among those were Rachel Carson whose book, Silent Spring, made some startling revelations (which some have might deemed as anecdotal). Perhaps it was Ms. Carson’s time for conjecture. Nevertheless, her book really caught the attention of America and made us take a second look at the “progress” we were becoming so comfortable with. Thank goodness. If not for insightful thinking like her’s, we might have inadvertently sped up our own extinction-if extinction was in the higher power’s master plan, that is.

Other people of the chemical era, such as Everett J. “Deke” Dietrick, further enhanced the field of biocontrol by publishing the Five Features of IPM, a paper which stated some salient, undeniable facts about this, then, very new science. The paper highlighted the need to:

  1. Avoid the use of disruptive pesticides.
  2. Build refuges for beneficials.
  3. Monitor insect ecology.
  4. Develop cultural practices.
  5. Release beneficial organisms.

This paper was published in 1969. Back then people who weren’t spraying pesticides on their crops were probably, as the song goes, “smoking dope and drinking wine.” A grand era of lavish self-indulgence and self-abuse, perhaps.

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