A new study conducted on the walking stick insect revealed a surprising discovery: less effective insect camouflage will produce a domino effect of accelerated predation on other species.
The study focused on the Timema cristinae, a walking stick insect found in California. Previous research on these walking stick insects revealed that the chameleon-like species produce two different types of babies – one which blends well in greenish environment, greenbark ceanothus; and the other which show white stripes on its back to camouflage within the chamise with thin, needle like leaves.
Tim Farkas, lead author of the study from the University of Colorado, and his colleagues showed that the camouflage of these particular insects evolved very fast. Should it fail however, it will create a disturbing domino effect impacting other plants and animals within the ecosystem.
"We have combined both experimental and observational data with mathematical modeling to show that evolution causes ecological effects and that it does so under natural conditions. We also focused simultaneously on multiple evolutionary processes-including natural selection and gene flow-rather than just one, which affords us some unique insights," Farkas wrote in the report.
The researchers were able to document the impacts on the ecosystem such as increased predation on other insects which also thrive in the same area. The study of the two types of plants and the camouflage of the insects reveal that the insects blend well in their normal environment. However when the striped insects were placed in the greenbark ceanothus; and the greenish, unstriped insects in the chamise, insect predation increased.
For example, a walking stick insect which failed to camouflage well in its surroundings will probably get eaten by birds, which will most likely start to eat the other insects in the area such as caterpillars, spiders, plant hoppers, etc. This cascade of events will go on and in turn affect the flora itself.
"Our study shows that the evolution of poor camouflage in one species can affect all the other species living there and affect the plant as well," Farkas said.
"We're hoping our research helps biologists to appreciate the extent of dynamic interplay between ecology and evolution, and that it can be used by applied scientists to combat emerging threats to biodiversity, ecosystem services, and food security."
The study was published in the Oct. 21 issue of Current Biology.
