Will Dormant Oil Harm Praying Mantis Cocoons?

Three questions:





1) Will Dormant Oil Harm Praying Mantis Cocoons? (Getting ready to spray dormant trees and ornamentals.)





2) Planting dahlias even though pests love them: snails and slugs - spider mites and red spiders - earwigs and cucumber beetles. Question: Will Insecticidal Soap treat all the above, or can you recommend a product that will help to control dahlia pests? "Magic" has been recommended to me for snails and slugs. Malathion has been recommended to kill the others. My preference is biological control.





3) a clematis last year had a horrible problem with red spiders. Any suggestions about this?





Thanks much,

Will Dormant Oil Harm Praying Mantis Cocoons?
Yes, dormant oil will kill mantis cocoons. It works by coating and "smothering" eggs of insect pests that have laid over for winter to hatch in spring. This is why it's applied in winter. Your desire to use only biological control is a tough order to accomplish. With all the insect pest nowday's, total control is nearly impossible without using chemicals. You will always have plant damage while trying to control biologically. If you wish to use biological control for the snails, put a ring of "table salt" around the plant area. Snails will not cross through the salt, (it will dissolve them). An insecticidal soap for mites may work, but will not totally eliminate the problem.. Spider mites require a certain chemical for control. They have an entirely different digestive system than the normal insect, and a "mitacide" or "acaracide" is needed to eradicate them totally. Even "diazinon" or "dursban" will not totally control them. Hope this helps somewhat..
Reply:Rose H., I did not see your excellent response to my query. I have relocated Mantis cocoons for years and generally place them inside another shrub for protection. It's extra work, but they're dear to me. Thanks for your helpful advice. Report It

Reply:1. Yes. If you can find the cocoons, relocate them to an area you are not spraying (good luck on that one!).





2. I do not suggest salt for slugs or snails as you may inadvertantly poison your soil (a lot of soils have a high concentration of salt from manure products. Have your soil tested by your county extension office). There are several baits on the market that are good--Escar-go is labeled organic; and some of the other major players in the chemical controls have baits out that are not toxic to pets or children (check the label). Spidermites are a big problem and resistent to many controls. You will most likely have to find a product labeled miticide. There are some pretty good 3 in 1 products (fungicide, miticide, insecticide) that, when you follow the directions, are relatively safe. Spidermites usually prefer plants under dry, stressed conditions, so good garden cultivation and even moisture may minimize the damage. If your garden is relatively small (and you have the patience) take a bucket of soapy water and knock the cucumber beetles into the bucket.





3. Where I live red spiders are the same as spidermites, so the information in 2 would apply. You can also call your extension office for more information on products/controls they suggest for your area.