Years of boom and bust: Phenology of the tropical deciduous tree, Senna polyantha and its bud predator, Anthonomus rufipennis LeConte, in central Mexico

The reproductive phenology of the tree, Senna polyantha (Collad) Irwin & Barneby (Fabaceae) and its weevil bud predator Anthonomus rufipennis LeConte (Coleoptera: Curculionidae) were monitored over a period of six years in a tropical deciduous forest of central Mexico.  Rainfall during the six year period was highly variable with aberrant annual patterns. The host tree displayed non-fixed reproductive responses to precipitation events and flowered regardless of season.  Weevils were also flexible in feeding and oviposition responses to available buds.  Population densities of weevils were affected by the flowering period of the previous year. Early flowering (Feb-May) resulting in high population densities in subsequent months, whereas later flowering during the year resulted in lower densities in subsequent years.  Bud damage by weevils was generally weakly correlated with final fruit production, although during years of abnormal precipitation fruit production was significantly reduced. Results suggest that continued aberrant climatic events will exacerbate population fluctuations of A. rufipennis and reproductive output of Senna polyantha; a pattern which is probably indicative, in general, of herbivorous insects and their host plants in seasonal tropical forests.