lily beetle

[gardin]

Hi, I just discover this group, and need some advices/opinions.

I learned today that I have lily beetles in my front yard. I am in Ontario (Can). What a disgusting creature! Its larvae live in its own excrement!

I visited a local garden center. They adviced me to use Bug-B-Gon to "drench" around the lily plant, and I can spray Aim (containing Pyrethrine). What a product! It kills upon contact. But the larvae have to be picked out by hand!!!!

My question are:

1) I have used Aim, I will drench around the plant now and in the Fall, is that enough to protect the plant? Will they come back next Spring? 2) Do they cause any harm to neighboring plants/trees/shrubs?

Please advice, and please give details since I am not a flower/plant guy at all. Thanks in advance. Mic -

[RoyDMercer]

Yes. Almost all garden insecticides are only temporary solutions. There are some insecticides which are systemic in that they are absorbed by the plant and work when the bug starts to eat the treated plant. These types of controls will last longer than most other types, but I don't think the effect would last from one year to the next. Systemic insecticides are generally the most toxic to people.

Probably not directly all that much, but many insecticides will kill beneficial insects, such as bees and worms, which could indirectly harm plants.

Insecticidal soap should kill the larvae, although it may not kill the beetles themselves. Of course if you keep killing the larvae, eventually the adult beetles will disappear. Insecticidal soap only kills on contact and will have very little lasting effects. Neem should kill both adults and larvae, but it's effects last a bit longer than insecticidal soap and it will also kill bees. It's not a good idea to use Neem around plants that are currently flowering which you want to allow pollination. Examples of this would be flowering fruits and vegetables and annuals which you want to naturally reseed. Neem suppossedly is mildly toxic to plants, but I have not personally observed any problems with its use.

As with any insect problem, you generally want to find the product which is tailored only to the type of insect you are trying to remove and not to beneficial insects, or at least use one that doesn't persist for very long. Insecticidal soap is usually my first choice because it only kills on contact, however it will only kill soft bodied insects. Dish soap will perform the same function, but is not recommended because the additives in dish soap are harmful to plants.

[J.Caldwell]