BMAA in cycad-feeding Lepidoptera: defensive sequestration or bioaccumulation?

Many herbivorous Lepidoptera accumulate plant toxins within their own tissues as a defensive strategy. Pioneering research in this area was conducted by Miriam Rothschild and Deane Bowers, who showed that the cycad-feeding butterfly Eumaeus atala sequester toxic compound cycasin thereby deter vertebrate invertebrate predators. The current study focuses on another cycad compound, β-methylamino-L-alanine (BMAA), is known to of insects other herbivores, which has been shown have neurotoxic effects humans. Chemical analyses revealed BMAA accumulates both immature adult E. , well lepidopteran, Seirarctia echo . However, distribution across life stages did not conform patterns predicted for sequestration, subsequent behavioral experiments with ants these predators were deterred BMAA. Our results suggest high levels likely reflect passive bioaccumulation rather than sequestration. Combined previous work provide an example two different single herbivore species via mechanisms implications ecology evolution. They lay groundwork further investigation into processes underlying active sequestration non-adaptive bioaccumulation.