A bacterium transmitted via beetle poop is threatening bright blossoms and bulbous vegetables in the USA, Scientific American reports. By the time yellowing leaves and signs of wilting become apparent it is too late. At that point infected pumpkins, melons, cucumbers or squash plants can only be isolated in hope of minimising the damage. Crop yield losses can be as high as 80 percent.
The killer, a bacterium called Erwinia tracheiphila, was first described in scientific literature some 120 years ago when it was reported in cucumber, melon and winter squash fields in Michigan.
An AgScience check shows it is listed as a regulated item on New Zealand’s Biosecurity Organisms Register for Imported Commodities, which records organisms that may be associated with plants or plant products that are imported into New Zealand. The quarantine status for each species is indicated – that is, regulated or non-regulated.
“Appropriate action” will be taken by the Ministry for Primary Industries for regulated species intercepted at New Zealand’s border.
The list is updated frequently, usually at 1-2 week intervals.
The increasing acreage of these plants in the USA, along with the practice of sowing more fields with one or a few crops—rather than a wide variety—appear to have helped the microbe gain traction, Scientific American reports.
It is being blamed for tens of millions of dollars in losses each year.
“To be honest, it’s in every field I go to in the Northeast and mid-Atlantic, unless the plants are completely doused in pesticides,” says Lori Shapiro, an evolutionary ecologist who researches the involved bacterium at North Carolina State and Harvard universities.
The microbes have also taken out gourds and melons across Kentucky and Iowa.
Agricultural experts are concerned the bacterium might creep into new areas like the southeastern or southwestern USA as well as Mexico.
Recent discoveries by Shapiro and colleagues are providing fresh insights into how these microbes hijack their hosts and manipulate insect behavior to help E. tracheiphila proliferate. They are transmitted to gourds and other hosts such as cantaloupe and honeydew melon through beetle excrement.
More details can be found in the American Scientific report (HERE).
Researchers do not know why the blight has apparently not spread to (or at least not been detected) in Texas or California, even though there are available crops and possible bug carriers in those states. These factors suggest there may be some genetic resistance or other factors about potential beetle carriers that could be explored.