Taken from Eclectic Gardener @ www.teachinggarden.org
Written by Alan Hickman

If your plans got washed out last Sunday, please accept my apology. For weeks, I’d been wishing for a good day-long soaking rain, to get at least some moisture back into the soil, but I forgot to be specific. "Between 11 p.m. and 5 a.m. mid-week" might have been a prudent codicil!
Since Colorado Potato Beetle picking season began, there has been lots of time to contemplate the way promising ideas and good intentions almost invariably turn out to have quite unforeseen side effects.
Controlling Colorado Potato Beetles is itself a perfect example of good intentions gone awry. Peel Teaching Garden volunteers grow produce for donation to a local low/no cost eatery and food bank and one of the vegetables most asked for is potatoes. This year the garden area planted to potatoes is sixty feet long by thirty feet wide, double the size of last year so, all things being equal, it should produce double last year’s crop.
Each year the potatoes are planted in a new area that has lain fallow for more than a decade. De-weeding and fertilizing are both accomplished by piling straw and cattle manure several feet thick over the area and leaving it to rot for about eighteen months. By planting time, the soil has a depth and quality of which most city gardeners can only dream.
Despite the sanitation, fertility and the provision of adequate irrigation, by mid June, the Colorado Potato Beetles are in full battle order. Left unchecked, the population could strip the leaves off the entire potato patch in a matter of a few days and reduce the crop to practically nothing. Once the potatoes were defoliated, the beetles would then migrate to any tomatoes, eggplants, peppers or whatever other solanaceous crops or weeds that the adults could get to.
Last year it took about an hour to make one pass over the potatoes, picking off the beetles. This year, twice the area, twice the time required. Every day someone spends at least two hours, walking up one side of each row and down the other, picking off adults and larvae. The task has to be done each and every day, otherwise the numbers become overwhelming. Even under the pressure of daily hand-picking, in really hot weather, the beetle population soars.
On the morning of 26 June, the cull came to seven adults and 680 larvae. And, yes, I did count them. (See www.teachinggarden.org click ‘Peel Teaching Garden’ and ‘Photo Gallery’ and scroll down for pictures.) The following day the count was similar, then the temperature fell and the pick reduced to maybe a couple of hundred larvae a day.
Most people think that picking squishy grubs and dropping them in a pot of soapy water is a pretty disgusting way to spend a couple of hours. After a couple of weeks though, all the stooping down and reaching doesn’t hurt so much and the job can be quite interesting. The eye becomes remarkably adept at spotting the distinctive hump-shaped larvae bodies and, even on a windy day, the most fleeting flash of red triggers recognition.
Although we only pick the CPBs, there are all sorts of insects making a living on the plants. The common ladybird beetles will actually prey on the smallest CPB larvae but on only one occasion have I ever seen predation in progress, a ladybird with a larva in its jaws. There is also a sort of stink bug that predates CPBs but I’ve only seen one of those bugs in the entire field so I don’t think it will have much effect on the CPB population.
If all you have is half a dozen plants in a home garden, then hand picking certainly can be used to effectively keep the CPBs to acceptable levels. It is when production is scaled up that the unfortunate side effects become apparent.
If it takes about 2 hours to pick an area of 60 x 30 feet or 1,800 square feet (0.041 acres), it would take one person 48 hours to hand pick one acre. Put another way, it would take 5 people about 10 hours to pick one acre. At $5.00 an hour, one picking would cost $250.00. Over a fifty day growing season that would be $12,500.00 an acre. With a typical yield of 20,000 lb. of potatoes per acre, that’s over sixty cents a pound just to control one pest.
While cost is an obvious ‘unfortunate side effect’ of hand picking, a more problematic question is: if it takes five people to keep one acre of potatoes clean, without even considering the meager $5.00 an hour bit, from where would the hundreds of thousands of people come who would be needed to hand pick all the potatoes grown in Canada?
So, why does PTG bother with hand picking? Because it is primarily a ‘teaching’ garden and most people have never grown a potato. If students participate in the most basic pest-control process, they have a practical basis for forming informed opinions. Experience won’t eliminate choices with unwanted consequences, but it might serve as a reminder that even simplicity can come with a high price.

Day +18un with cloud Winds W20km/h P.O.P.30%
Night +7 a few clouds Winds SW5km/h P.O.P.20%