In the battle for bugs, wolf spiders are outwitting carnivorous plants, according to the first study to show members of the plant and animal kingdoms competing for prey.
In parts of Florida and southern Georgia, two species of wolf spider eat the same insects as the pink sundew—a type of carnivorous plant.
Sundews catch bugs using a sticky mucilage on the tips of their leaves. The small plants then release digestive enzymes, which begin to process the trapped animals, leaving only their exoskeletons behind.
Sosippus floridanus spiders, meanwhile, build funnel webs slightly off the ground, at the same height as the sundews. And a wandering wolf spider species, Rabidosa rabida, actively hunts for the same insects the sundews tend to trap. (See spider web pictures.)
In the field the team saw that, when S. floridanus is in close quarters with the sundew, the spiders build larger webs farther away from the plants, presumably to snare more meals than the sundews' leaves.
This led the team to suspect that the spiders were hurting the plants via competition.
Laboratory experiments with the hunting spider R. rabida later confirmed that the presence of spiders can deprive the plants of bugs—and thus vital nutrients.
The plants become weaker overall, producing smaller leaves and fewer seeds, according to study co-author Jason Rohr, an ecologist at the University of South Florida.
There's no evidence so far that the plant responds in any way to the spiders' presence, though research is underway to investigate that, Rohr added. (Related: "Plants Can Recognize, Communicate With Relatives, Studies Find.")
Overall, the discovery contradicts a long-held assumption that competition for food mostly occurs among closely related taxa, or categories of organisms, he said.
"We have pretty convincing evidence that you get competition between very distantly related taxa."
In parts of Florida and southern Georgia, two species of wolf spider eat the same insects as the pink sundew—a type of carnivorous plant.
Sundews catch bugs using a sticky mucilage on the tips of their leaves. The small plants then release digestive enzymes, which begin to process the trapped animals, leaving only their exoskeletons behind.
Sosippus floridanus spiders, meanwhile, build funnel webs slightly off the ground, at the same height as the sundews. And a wandering wolf spider species, Rabidosa rabida, actively hunts for the same insects the sundews tend to trap. (See spider web pictures.)
In the field the team saw that, when S. floridanus is in close quarters with the sundew, the spiders build larger webs farther away from the plants, presumably to snare more meals than the sundews' leaves.
This led the team to suspect that the spiders were hurting the plants via competition.
Laboratory experiments with the hunting spider R. rabida later confirmed that the presence of spiders can deprive the plants of bugs—and thus vital nutrients.
The plants become weaker overall, producing smaller leaves and fewer seeds, according to study co-author Jason Rohr, an ecologist at the University of South Florida.
There's no evidence so far that the plant responds in any way to the spiders' presence, though research is underway to investigate that, Rohr added. (Related: "Plants Can Recognize, Communicate With Relatives, Studies Find.")
Overall, the discovery contradicts a long-held assumption that competition for food mostly occurs among closely related taxa, or categories of organisms, he said.
"We have pretty convincing evidence that you get competition between very distantly related taxa."
ไม่มีความคิดเห็น:
แสดงความคิดเห็น