Re: [gardeners] Saturday in the garden

Ron Hay (
Mon, 15 May 2000 11:29:58 -0700

Dorsett wrote:

> Ron,
> About those tobacco budworms:
>  Insecticides containing Bacillus thuringiensis/Bt (Thuricide, Dipel, etc.)
> are effective biological controls when used on some plants, but not really
> on geraniums. You might want to plant some petunias as a trap crop...and
> spray them with Bt.  The budworms eat more of the flower surface on
> petunias, and ingest Bt as they nosh.
> Eggs are deposited on leaves and buds: subspherical with a flattened base,
> about 0.6 mm in diameter, and white or cream in color. They develop a
> reddish-brown band just prior to hatching.  Hatchlings eat leaf material for
> a couple of days, then move into buds.
>   Parasitic wasps are predators, Campoletis sonorensis, Cardiochiles
> nigriceps, and several Polistes spp. paper wasps.  Several diseases,
> including the microsporidian Nosema heliothidis Lutz and Spendor, also
> reduce budworm populations.
>  Barb in Southern Indiana  Zone 5/6
>     A root is a flower that disdains fame.

Hi, again, Barb,

Thanks again for your very kind input. The problems with the pelargoniums is
that we have no room at all for petunias. Most of are collection of zonals and
regals are in pots; some are in amongst the calla lillies and bird of paradise,
filling in the empty spaces.

I will see about predator insects, but am not sure there are enough budworms to
feed a host of beneficial insects. My collection is about 30 plants, most in
pots, many of them very young. I will just have  to try to be inventive, but

Thanks again,