ROOT WEEVILS




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Do you have any leaves that look like the ones in this picture?  This kind of damage is produced by adult root weevils.  Root weevil larvae overwinter in the soil and can do serious damage to root systems.  It seems that excellent control of root weevils can be achieved by applying nematodes in the fall when the soil temperature is right (now through early Oct) and then applying hypoaspis, another beneficial insect, in the spring and summer. This two pronged treatment should go a very long way towards solving getting rid of this difficult pest. Both Nematodes and Hypoaspis are microscopic organisms that seek out and destroy root weevil larvae, thus disrupting the cycle so there are fewer adults feeding during the growing season.  Rhodos, Camellias, Laurels, Bergenia, Heuchera, Primula and a host of other plants are all susceptible to weevil damage.  The nematodes are available in September/October and come in small packages, each enough to treat 12 to 15 average sized rhodos.

Hypoaspis: New Treatment for Vine Weevils – For the last year or two we’ve been hearing anecdotal evidence that fungus gnat predators, aka Hypoaspis miles, are effective in the fight against the black vine weevil. We’ve heard enough now, that we’ve decided it’s time to spread the news.
Applied Bionomics is a local company that is a world leader in the development and production of biological pest controls and they have been testing Hypoaspis with impressive results. Hypoaspis goes after the root weevil larvae thus decreasing the numbers of adults. It takes a year or so for the results to show, but in test areas the weevils have all but disappeared, as evidenced by the healthy foliage on plants that were previously badly eaten. It also appears to be effective against cutworms and other grub producing species as well as flower thrips.
Hypoaspis can be applied at any time of year and needs to be used just once as it will establish in the garden once introduced. It comes mixed with sawdust and all you have to do is shake a tablespoon or so around plants that show signs of weevil damage. For a small garden or one with only a few affected plants there is a consumer sized package for $16.99 and for a larger garden there is a commercial sized package for $52.00.