“When Joro spiders first arrived stateside over a decade ago, scientists worried the massive black and yellow spiders would gorge themselves on the same bugs as native spiders (or even the native spiders themselves).
If the invasive arachnids did make massive meals out of Georgia’s insects, the local orb weaver population — already facing dangers from insecticide and pesticide use — could suffer.
But a new study from the University of Georgia may ease some of those concerns…
The researchers analyzed the stomach contents of more than 200 Joro spiders from 33 sites across Georgia and South Carolina. They compared DNA fragments found in the digestive tracts of these spiders to more than 140 native orb weavers from across the two states.
While Joros do eat some of the same insects as orb weavers, the species’ diets differed significantly, the study found. In fact, the Joros preyed on 26 unique species that the native spiders didn’t touch, including a variety of bugs such as leafhoppers and aphids.
Native spider species had the same diet regardless of whether Joros were present in the area, the study found. This finding suggests that Joros aren’t necessarily making it more difficult for orb weavers to find their favorite snacks.”
From University of Georgia.