Q. I’ve just spotted Colorado potato beetle bugs and
larvae on my tomatillo plants. I didn’t even know what they were until I did
some research. I’ve never seen them out here before. I can’t find an organic
pesticide that will kill them without hurting the bees and other beneficial
insects. Do you have any advice for me?
larvae on my tomatillo plants. I didn’t even know what they were until I did
some research. I’ve never seen them out here before. I can’t find an organic
pesticide that will kill them without hurting the bees and other beneficial
insects. Do you have any advice for me?
A. Make sure it is actually the Colorado potato beetle
and not a look-alike insect called the Ten-Lined June Beetle. I have not seen
the Colorado potato beetle in the Las Vegas area yet but it is possible. Until
recently, Nevada was one of four US states that didn’t have this pest.
and not a look-alike insect called the Ten-Lined June Beetle. I have not seen
the Colorado potato beetle in the Las Vegas area yet but it is possible. Until
recently, Nevada was one of four US states that didn’t have this pest.
 |
| Ten-Lined June Beetle |
But I
have seen the Ten Lined June beetle here and they look very similar to the
Colorado potato beetle. I posted a picture of this critter on my blog. The
safest way is to pick them off as you see them. In small garden plots this
works well. You can also use a cordless vacuum cleaner and suck them up that
way.
have seen the Ten Lined June beetle here and they look very similar to the
Colorado potato beetle. I posted a picture of this critter on my blog. The
safest way is to pick them off as you see them. In small garden plots this
works well. You can also use a cordless vacuum cleaner and suck them up that
way.
As far
as sprays go an organic/biological pesticide called Spinosad, which is
available in many nurseries now, will give some control.
as sprays go an organic/biological pesticide called Spinosad, which is
available in many nurseries now, will give some control.
 |
| Colorado potato beetle adult (striped) and larvae without stripes on potato leaves in Kosovo. |
Another
organic/biological control chemical is Bacillus
thuringiensis (Bt) var. San Diego (also called variety tenebrionis) gives
some control if they are not resistant. This particular type of Bt controls
beetles. But this organic spray is hard to find locally. You will probably find
it only online.
organic/biological control chemical is Bacillus
thuringiensis (Bt) var. San Diego (also called variety tenebrionis) gives
some control if they are not resistant. This particular type of Bt controls
beetles. But this organic spray is hard to find locally. You will probably find
it only online.
There are Bt sprays in the nurseries
but this is the wrong Bt spray for Colorado Potato Beetle. The one in the
nurseries is Bt var. kurstaki (Btk). This Bt is used to control larvae or
caterpillars that form moths and butterflies like the tomato fruit worm, tomato
hornworm and grape leaf skeletonizer.