ANTIBIOTICS AS PESTICIDES? Citrus growers in Florida have been struggling to combat citrus greening disease—a disease spread by an invasive insect known as Asian citrus psyllid.
Citrus greening is destroying crops, turning fruit bitter, and causing heaps of lost trees. Unable to curb the disease, growers have been resorting to using oxytetracylcine and streptomycin. Studies show these substances harm soil microorganisms and can cause health problems. Yet the Trump administration recently approved the use of 2.23 million pounds of the antibiotics on fields of trees- this is 36 times more than that used on humans each year!
How will this enhance agricultural runoff, which is already a tremendous problem. What wide scale destruction could result to the water, to soil, to the animals and people exposed? How will this impact antibiotic resistance?
Farmers may be desperate, but by using natural means like predatory wasps, the phyllid’s natural predator, they may have a healthier outcome in the long run rather than a risky temporary solution. By improving soil health could the trees naturally resist the psyllid? Nature nearly always has a solution that’s better than any chemical could pretend to be.
Or is too late, have we already decimated the beneficial wasp population with our overuse of pesticides and fungicides? We’re already causing the collapse of several beneficial bugs, pollinators, birds and bats with our overzealous use of agricultural chemicals. These very creatures often are the solution we need in times of environmental crises.
An insect Armageddon is under way, say many entomologists, the result of a multiple whammy of environmental impacts: pollution, habitat changes, overuse of pesticides, and global warming. And it is a decline that could have crucial consequences. Our creepy crawlies may have unsettling looks but they lie at the foot of a wildlife food chain that makes them vitally important to the makeup and nature of the countryside. They are “the little things that run the world” according to the distinguished Harvard biologist Edward O Wilson, who once observed: “If all humankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed 10,000 years ago. If insects were to vanish, the environment would collapse into chaos.” Source: The Guardian
If we aren’t careful the world will be barren of insects and then we will be in great trouble indeed.
Studies urge Caution:
Dangers of Streptomycin and Oxytetracycline
Streptomycin, an antibiotic produced by Streptomyces griseus that has long been used as a fungicide , also has bactericidal activity. Streptomycin interferes with amino acid synthesis. In Escherichia coli, application of streptomycin caused misincorporation of an isoleucine molecule in the phenylalanine polypeptide chain associated with 70S ribosomes . Another research with a thermus thermophilus mutant strain suggested that misreading of the genes coding for amino acid synthesis explains the negative effect of streptomycin on bacteria . Furthermore, Perez et al.  found that streptomycin could also be a nonselective excitatory amino acid (EAA) receptor antagonist. This antibiotic selectively blocked amino acid receptors in the anterior vestibular nerve fibers of Ambystoma tigrinum, a salamander, suggesting that it could also be toxic to eukaryotes, in addition to fungi and bacteria.
Oxytetracycline is widely used in agriculture because of its broad-spectrum antibiotic activity. It is also registered as fungicide in New Zealand and VietNam, according to the information provided by Pesticide Action Network of North America (http://www.pesticideinfo.org/Detail_ChemReg.jsp?Rec_Id=PC38140). Previous research reported inhibitory effects of oxytetracycline on protein synthesis in bacteria through interference with the ternary amino-acyl-tRNA complex binding to the acceptor site of ribosomes , leading to retarded bacterial growth, disordered microbial community structure, and limited microbial ectoenzyme activity in the soil system [21, 40]. Therefore, caution must be taken with the application of oxytetracycline to control fungal diseases, as it is antibiotic and impacts bacteria.
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