Ugh!  I went to our four seasons patio last night to enjoy some of the plants I keep there for the Winter.  My Bay Laurel tree appears to be doing very well from a distance - lots of nice, new growth, a pretty green color.  But, when I stepped in to take a closer look, I found sticky "goo" on some of the leaves.  Sticky goo on houseplants is never a good thing.  It usually indicates unwelcome visitors in the form of aphids or scale insects.  In this case, it is scale insects.

Scale insects are those brownish - grayish little disk-like things stuck to the underside of leaves, especially along the central leaf veins, or clustered along the stems.  They are usually about the size of a pin head, but can be smaller or larger.  Whatever size, they are ugly and a challenge to control.  And Bay Laurel is one of their favorite buffets, so they don't give up easily. 

For young scale insects, insecticidal soap effectively kills them, but in my experience, I don't see the little buggers until they are old enough to resist harm from the soap.  So, tonight I'll be out there scraping off the visible insects with my fingernail and then wiping all the leaves and stems with a cloth soaked in 70% rubbing alcohol.   In the past, I have also resorted to putting alcohol in a spray bottle and spritzing the hard to reach places, especially where the leaves attach to the stem.  You need to be careful with this form of application, though, as alcohol can burn the leaves.  Then it will require careful watching, as they tend to re-infest easily.

You can also try to control them and other sucking insects with a "systemic" insecticide, an insecticide form that is highly soluble in water and therefore is easily transported into the tissues of the plants.  Imadocloprid formulated for indoor use, generally a 0.22 % formulation, is one of the most common.  It comes in granular form and is scratched into the surface of the soil.  Since I use my Bay Laurel leaves a lot in cooking, I hate to use insecticides, even though it is stated to be safe for human consumption after 14 to 21 days.  There is a question in my mind as to how that works since it also says it stays active in the plant tissues for up to 8 weeks. Hmmm????

The other downside of imadocloprid is that, like most pesticides, it isn't smart enough to distingquish good bugs from bad - it kills indiscriminately.  There are a couple ladybugs who hitched a ride into the patio last fall that I don't want to harm, and I don't want to take the chance that there would still be imadocloprid active in the plants when I move them outside for the bees and butterflies to enjoy this Spring. 

So, I guess I have a Friday date night with my Bay Laurel tree and the rubbing alcohol bottle.