10 days is a long time in "bug years"... we've had a lot of rain as well which washes away your sevin... couple this with a few very hot days and voila... more bugs...

All the other issues with using Sevin aside, Sevin isn't a "preventative", it's an insecticide. Insecticides work by coming into direct contact with the bugs.

Dave

I recall the directions said something about only reapplying X number of times per season, not after each rain. That suggested to me it had a persistent effect. I don't know, still learning.

Agreed with -golf and -dirt. You want a Btk (I think they call it 'Bonide') and some lightweight row cover. Preventative sprays won't work in the veggie garden, unless you mean some sort of garlic spray.

Dan

As Dan says, there's a strain of BT that works on PBs -- especially the larva. It's marketed by one or another of the pesticide companies under the name "Colorado Potato Beetle Beater." There are probably a few other commercial names as well.

Sevin (Carbaryl) will take out potato beetles but only the ones that are present when you spray. It is a very short life ( 12 hours) insecticide. Most insecticides available to home gardemers will also have a short life. As Dan said, contact insecticides are not useful as preventives. Stomach poisons like Bt in its several forms is more persistant, but it is always best to identify the problem before attacking.

You are certainly free to do as you wish... But, having openened the topic for opinions, here's mine for your consideration... Seems like it would be easiest (and free) to just squash the 5 bugs and their eggs. You've already done the hard part - finding them. I assume you are growing potatoes to save money or to have fresh organic ones. The $ you spent on Sevin is probably more than the cost of any potatoes you might lose by not using it. If you want to eat food that had carbaryl on it, it seems easier to just buy them and leave the chemicals to the professionals. You could investigate a companion plant for the potatoes that would attract a predator of the beetles. Whatever you decide, best of luck to you and your potatoes!

Here is a link that might be useful: Sevin is not an entity I wish to support or perpetuate

Here is an unusual way to get rid of those potato bugs it may sound crazy but I don't have the time to hand pick bugs and I do not want to use any sprays on my plants this is quick and it works. I put an inch or so of soapy water in my shop vac and go up and down the row sucking them off the plants. You have to do it freq as the new ones hatch but it only takes a short time. If you keep up with it they are under control and even gone. My garden has 3 rows of potatoes and each row is forty feet long. The neighbors my look at me strange but oh well.

From my observations, it is the CPB larvae which cause severe damage to potatoes and eggplants. The adult beetles not so much, although they are the ones which lay eggs by the thousands. If you can hand pick a lot of adults you are ahead of the game because you have greatly reduced future numbers of larvae. both adults and larvae are slow movers and easy to pick.

If you decide on Bt, be sure to get the right type. You need the san diego strain. And learn about when to apply it. Timing is critical. Do some research.

Another alternative is Spinosad, which is sold under several brand names.

Jim

Here is a link that might be useful: Controlling CPB

I agree with Jim.. I had huge problem with CPB on my eggplants earlier this year, posted some pics here to identify then went about handpicking. First day I probably took off 8 adults and 50 larvae, next day was 5 and 1, day after was 1 adult... no more since!. I do check them every day now.

Sevin is most effective spray directly on the insects. I did use it on flea beetles on my eggplant, but had to spray a few times. Instead of dousing the plant, I just sprayed what bugs I saw. If it was a bug that was easy to pick off, I'd rather do that.

Having trouble this year with seven calls for 4 ounces per gallon put it up to 8 per gallon they just thank me for the shower they are stripping the plants cleam