Info About Hibiscus Sawfly on Hardy Hibiscus

Hi everyone, I don't usually post here. In an effort to have a plan on how to approach controlling Hibiscus Sawfly larvae for next year, I have discovered some information that I thought others would find useful. I would prefer to be completely organic in all my gardening efforts, however sometimes when a plant seems it is not going to make it without - I will resort to chemicals. (This particular problem the chemical would be Spinosad) I always feel that this is perhaps ruining all my efforts of letting the natural order of things occur. Example being, I am most likely harming the beneficial insects along with the harmful ones and potentially poisoning small birds or frogs which I enjoy having in my garden. If you feel like me you may find this article interesting. http://www.theprairiestar.com/articles/2009/07/17/ag_news/farm_and_field/field1.txt
The most important thing I took from the above article is leaving my Hibiscus stems through winter. I know they are awful to look at, but if it is going to help keep my Hibiscus leaves from looking like delicate lace work the next year, then so be it. I believe the article said leaving at least 6" would be good but I'm not taking any chances and leaving the whole things just in case. Another thing I've taken from the article which may not be an issue for others is 'Not' to burn my ornamental grasses which are growing on the sides of all my Hibiscus plants. We did this in spring and I wonder if that has anything to with the heavy damage from Sawfly larvae this year.
In case you are curious as to what they look like, here is a link to an image of these beneficial wasps (which I did see on my Hibiscus plants this year) Bracon lissogaster http://entomology.montana.edu/People/RKDPeterson/wss%20thumbs/Bracon%20lissogaster%20female_0011.jpg and Bracon cephi - I can't get a link directly to picture to work - here is the page that has pictures of them if you scroll down.) http://entomology.montana.edu/People/RKDPeterson/wssthumbs.htm
Hope this will be of help to some fellow DGers.

Edited Links

This message was edited Sep 28, 2009 11:22 AM