Phenological-plasticity
Guides
Euproctis chrysorrhoea
Brown-tail Moth
Euproctis chrysorrhoea, the brown-tail moth, is a univoltine forest pest with a highly polyphagous larval stage. Populations exhibit phenological plasticity, with larval diapause timing and winter feeding behavior varying based on host plant foliage persistence. The species demonstrates sequential host plant utilization during mass outbreaks and shows evidence of host-associated genetic divergence. Larvae possess urticating setae that pose human health risks.
Periphyllus californiensis
California maple aphid, Japanese maple aphid
Periphyllus californiensis is an invasive aphid species native to East Asia (Japan, China, Korea, Taiwan, Russian Far East) that has established populations in North America, Australia, New Zealand, and Europe. It is a specialist feeder on maple trees (Acer spp.), with documented hosts including Acer palmatum, A. japonicum, A. amoenum, and numerous other maple species. The species exhibits complex phenological synchrony with host trees, producing distinct larval morphs—non-summer-diapause larvae on unexpanded leaves and summer-diapause (aestivating) dimorphs on expanded leaves—based on host plant nutritional quality rather than genetic generation. High mortality (>99.9%) of summer dimorphs has been observed, with survivors resuming activity in autumn. The species has been recorded in Poland since 2009 and spreads via ornamental maple trade.