Is Spinosad, The Bio-Insecticide Safe ? | Farming Inspirations

Very low concentrations of the popular organic insecticide spinosad have been known to have profound effects on beneficial insect species particularly honey bees which includes vision loss and neurodegeneration.

Spinosad is a “biological insecticide”, a product naturally derived from the fermentation of the actinomycete “Saccharopolyspora spinosa”.

It is commonly used in crops like cotton, red gram, chilli, brinjal and soybean for the control of various pests like bollworms, shoot & and fruit borers, thrips, aphids and Jassids.

A study conducted by “The University of Melbourne used the vinegar fly-drosophila to analyse the impact of chronic exposure to lower concentrations (0.2 ppm) of spinosad and the resulting physiological impacts it causes.

Within a matter of 20 days, tiny doses of spinosad can have an alarming impact on the brains of adult Drosophila. Observing sections of brain tissue under a microscope demonstrated that there was an average of 17% of the fly brains destroyed due to exposure.

Neurons that serve vital functions die leaving large vacuoles, fluid-filled sacs, in the brain. This leads to neurodegeneration, blindness and behavioural changes in adult vinegar flies. As Drosophila’s genetic and biochemical factors resembles other insects, these impacts could be translated to other beneficial insects, particularly honey bees.

As a natural substance made by a soil bacterium, spinosad is often thought to be less harmful to beneficial insects and is frequently used as an alternative to synthetic insecticides.

There is greatly an assumption that organic equates to safer, but the equation is not the same and safe here. Spinosad is currently registered for use in over 80 countries, and it poses a far greater risk to beneficial insects than previously thought.

A similar study revealed that spinosad was found to have a much greater negative impact on vinegar flies at far lower doses than imidacloprid, a synthetic insecticide which has been banned in several countries for its impacts on non-target insects including honeybees.

Finally, the aim here is not to pin the blame on spinosad, it does show that having an organic label doesn’t always mean safer. All insecticides, no matter their source, need to be rigorously studied for any unintended ecological impacts in coming future.