All it's taking to transform the ecosystem of the Chihuahua desert is a 13mm long beetle called Oncideres rhodosticta, say researchers.
The beetle - mesquite girdler - is speeding up the degradation of grasslands in the Chihuahua desert, the landscape so stunningly depicted in this year's Oscar-winning film No Country for Old Men, says a new research.According to the research carried out by Benjamin Duval and Walter Whitford at New Mexico State University, the mesquite girdler does this by regulating the growth of the mesquite shrub, ensuring their offspring have a plentiful supply of food.
The beetles chew girdles around the older stems of the shrub, which forces the plant to regrow new stems the following year. The new stems supply the beetle larvae with food, but the mesquite shrub takes more nutrients from the soil for its increased growth, leaving less for the other plant species such as grasses.
Till 150 years ago, the North Chihuahuan Desert was completely covered in grassland. However, it is a completely different picture today, as dunes and mesquite shrubs cover much of the landscape.
"Although the desertification process was likely started by overgrazing cattle, the ecosystem engineering impact of the mesquite girdler could finish off the process," said Duval.
The research is published in the latest edition of the Royal Entomological Society's Ecological Entomology journal.
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