Organic Insect Control II

Wednesday, May 23, 2012

Many beetles begin their life as destructive larvae, as do most moths and butterflies. While no one minds doing in the white grubs of Japanese beetles that eat the lawn and emerge to devour the roses, the idea of reducing the number of gorgeous swallowtail butterflies by controlling their larva to save the parsley or dill plants is very objectionable. The nondescript winged mothers of cabbageworms and squash vine borers do not have as many fans, but until it is your crop lost, it is easy to say that you would never spray or dust them because you love butterflies and moths. Exclusion of the moths works well to control them without sprays or dusts, and when it comes to these particular mothers, it is far more effective than watching for signs of damage. Use floating row cover to shield the little plants for the first weeks and then remove it. You still must be vigilant, of course, to see masses of eggs laid even with exclusion and scrape them off right away. If you have ever had a small tomato plant disappear overnight, dig around in the soil to find a fat cutworm that lives in the soil and awaits the transplant trowel. These larvae are able to wrap themselves around little stems at soil level and sever your dreams of yummy vegetables as they cut. It is a simple matter of surrounding vulnerable transplants with ½ inch cardboard collars to deter cut worms. The physical ‘stomp and squish’ method applies to beetles and larvae alike and can be part of that daily garden walk. But where there is one, there are no doubt dozens and plants can be stripped overnight. At the first sign of larvae, spray or dust with BT (in Thuricide or Dipel), a bacillus that preys on all members of the Lepidoptera family, the moths and insects. It will not control white grubs and other beetle babies, which usually respond to 2 applications of milky spore fungus applied spring and fall. Like most things organic, predatory controls may not be fast, but are very effective in the long term.

Go back to Wormy Wisdom

Login or Register to comment post.