This year I planted a lot of fall tomatoes for market. Having experienced a great deal of worm problems in fall tomatoes in past years I decided to start this venture prepared, so I ordered a bottle of Monterey Garden Insect Spray. Made with a somewhat recently “discovered” ingredient called “spinosads”

Spinosads are a class of soil dwelling bacteria labelled Saccharopolyspora spinosa. Biological warfare, if you will. Like BT.

To quote the standard repository of all knowledge and wisdom (Wikipedia):

“Spinosad (spinosyn A and spinosyn D) are a new chemical class of insecticides that are registered by the United States Environmental Protection Agency‎ (EPA) to control a variety of insects. The active ingredient is derived from a naturally occurring soil dwelling bacterium called Saccharopolyspora spinosa, a rare actinomycete reportedly collected from soil in an abandoned rum distillery on a Caribbean Island in 1982 by a scientist on vacation^[1] . It has not been found in nature since that time, and was subsequently described as a new species. The bacteria produce compounds (metabolites) while in a fermentation broth. The first fermentation-derived compound was formulated in 1988. Spinosad has since been formulated into insecticides that combine the efficacy of a synthetic insecticide with the benefits of a biological pest control organism.”

Anywho…Sure enough after the plants set fruit, the hornworms came with a vengeance, and while my back was turned had defoliated several plants. So I pulled out the bottle and gave it a go. Surprisingly, for a not terribly popular organic insecticide, it worked great! I sprayed at dusk (while the bees weren’t hanging around), and the next morning I was rewarded with the sight of brown, shrivelled hornworms, either on the ground or hanging limply from the leaves. Like this dude:

Awesome right?

Yes, in a way, and while it was nice to have a cure-all for my trouble it was a bitter-sweet victory. And I probably won’t use it again on my fall tomatoes unless I absolutely have to. While, for insecticides, it’s pretty mild, and is OMRI listed and completely usable for Organic production.  It’s still highly toxic to bees and wasps. Less so to other beneficials. But, even that’s not so bad if you take into consideration the results of this study:

Although spinosad has low toxicity to most beneficial insects, initial acute laboratory tests indicated that spinosad is intrinsically toxic to pollinators. The hazard of spinosad to bees was evaluated using a tiered approach. Initial acute laboratory exposures were conducted, followed by toxicity of residues of spinosad on treated foliage, greenhouse studies to assess acute as well as chronic toxicity, confined field assessments, and finally full field studies using a variety of crops under typical use conditions. These data were used to assess the potential of adverse effects on foraging bees following the use of spinosad. This research has clearly demonstrated that spinosad residues that have been allowed to dry for 3 hr are not acutely harmful to honeybees when low-volume and ultralow-volume sprays are used. Further, glasshouse and semifield studies have demonstrated that dried residues are not acutely toxic, and although pollen and nectar from sprayed plants may have transient effects on brood development, the residues do not overtly affect hive viability of either the honeybee or the bumblebee. Field studies in which typical application methods of spinosad were used on a variety of crops have demonstrated that spinosad has low risk to adult honeybees and has little or no effect on hive activity and brood development. The collective evidence from these studies indicates that once spinosad residues have dried on plant foliage, generally 3 hr or less, the risk of spinosad to honeybees is negligible.

So why a bitter-sweet victory then? I sprayed at dusk, when no pollinators were out. I probably didn’t hurt a fly, especially since I sprayed pretty lightly anyway.

All the same, Organic farming and gardening is about prevention, not spraying the heck out of stuff. Products like the one I used are something you don’t want to grow to depend on. Still, it worked, and I’m glad I purchased it. Definitely a good thing to have on hand for bad times. You can get it here .