Scientists at Washington State University and China Jiliang University have discovered that the quality of the host rice plant determines whether the brown planthopper, a major pest on rice in Asia, grows short wings or long wings.
Wing size determines whether the insect can fly long distances to other plants or stick around and feed off nearby rice plants, said Laura Lavine, professor in WSU’s Department of Entomology.
“It’s all about the amount of glucose, or sugar, in the plant,” Lavine said. “Rice plants with higher glucose levels are older and dying. That increase in glucose causes adolescent brown planthoppers to develop into the long-winged adults. The plant really is telling the insect how to grow.”
“It’s a one-time decision,” said Lavine, who became the Entomology department chair July 1. “If the decision to stay and reproduce or migrate and fly away is incorrect, the brown planthopper is in trouble. Grow short wings when long wings are needed to move away and they die. Grow long wings when they could manage with short wings and they’re leaving a healthy food source and have to needlessly search for another home.”
Once insects reach adulthood, they can’t alter their body structure, she said.Paper. (open access)
Why does one get the sense that, if the plant were telling the insect anything, it would be telling it to buzz off no matter what?
The hope is now that this discovery has been made, other scientists could manipulate the insect into making long wings and leaving. The brown planthopper, Nilaparvata lugens Stål, is one of the most destructive rice pests in the world and threatens the sustainability of rice production and global food security.
“The results of this study will hopefully allow scientists a new way to figure out how to trick the brown planthopper into developing into the wrong form so that they die before they become pests,” Lavine said. – Xinda Lin, Yili Xu, Jianru Jiang, Mark Lavine, Laura Corley Lavine. Host quality induces phenotypic plasticity in a wing polyphenic insect. Proceedings of the National Academy of Sciences, 2018; 201721473 DOI: 10.1073/pnas.1721473115 More.
Given how many tricks plants play on insects it’s a wonder the rice plant hasn’t developed deceit already. Must be a bit slow if it needs human tutoring. 😉
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