Q. For the past three years these little black critters
have chewed holes in the leaves of my Mexican Primrose. What are they and how
can I get rid of them permanently? Since Mexican Primrose is not a food
crop, I sprayed them with Ortho’s Home Defense, but that may not be the best
solution.
have chewed holes in the leaves of my Mexican Primrose. What are they and how
can I get rid of them permanently? Since Mexican Primrose is not a food
crop, I sprayed them with Ortho’s Home Defense, but that may not be the best
solution.
 |
| BB sized holes in grape leaves from flea beetle feeding |
A. Thanks for telling me the insecticide you used but
legally you are not supposed to use an insecticide unless the label states it
can be used for that purpose. The active ingredient of the insecticide might
work on flea beetles but unless there is a given rate of application on the
label, then the rate to apply is not known. The rate of application can mean
the difference between control or no control.
legally you are not supposed to use an insecticide unless the label states it
can be used for that purpose. The active ingredient of the insecticide might
work on flea beetles but unless there is a given rate of application on the
label, then the rate to apply is not known. The rate of application can mean
the difference between control or no control.
Mexican Primrose and Flea Beetle Damage
Mexican
Primrose is notorious for flea beetle damage in the spring and sometimes fall
months. Knowing which flea beetle is yours is the first step in getting
permanent control. If you elect to go down this path, take five or six flea
beetles in a vial of alcohol to the Nevada State Department of Agriculture and
ask their entomologist in Reno to identify the type of flea beetle. Once the
flea beetle is properly identified, methods of permanent control can be
discussed. There is quite a bit of literature on permanent control without
chemicals.
Primrose is notorious for flea beetle damage in the spring and sometimes fall
months. Knowing which flea beetle is yours is the first step in getting
permanent control. If you elect to go down this path, take five or six flea
beetles in a vial of alcohol to the Nevada State Department of Agriculture and
ask their entomologist in Reno to identify the type of flea beetle. Once the
flea beetle is properly identified, methods of permanent control can be
discussed. There is quite a bit of literature on permanent control without
chemicals.
 |
| Flea beetles are quite small |
As far
as I am concerned, flea beetles are vagabonds and become a problem frequently during
the spring, and sometimes fall months. Mark your calendar because they will
come near the same date in the spring most years. This date signals you to
start looking for them or their damage and apply the proper control measure.
 |
| Heavy flea beetle damage on grape leaves |
Flea
beetles last about three weeks and they are gone. They can cause a lot of
damage in a noticeably short time. If you see damage during the fall months,
mark your calendar. Watch for holes in the leaves that signal their feeding has
begun. They hide out on the bottom of leaves so you must spray “up” as well as
over the top.
beetles last about three weeks and they are gone. They can cause a lot of
damage in a noticeably short time. If you see damage during the fall months,
mark your calendar. Watch for holes in the leaves that signal their feeding has
begun. They hide out on the bottom of leaves so you must spray “up” as well as
over the top.
Pesticides and Controlling Flea Beetles
Conventional
insecticides used for controlling flea beetles include Sevin (active ingredient
of carbaryl) or one of the pyrethrins (look for something ending in –thrin in
the active ingredients). These must be applied each season you see them. Once
damage is done, cut the plant back to get rid of the ugly parts, fertilize, water,
and let it regrow.
insecticides used for controlling flea beetles include Sevin (active ingredient
of carbaryl) or one of the pyrethrins (look for something ending in –thrin in
the active ingredients). These must be applied each season you see them. Once
damage is done, cut the plant back to get rid of the ugly parts, fertilize, water,
and let it regrow.