Mast seeding and Lyme disease

Abstract

In her cogent review of the factors controlling levels of Lyme disease, Randolph[1]makes one small error. She shows that `mast years' (high acorn crops) are associated with outbreaks of mice, with variable effects on densities of the ticks that carry Lyme disease. In years of very low or no acorn production, reduced mouse predation allows higher survival of gypsy moths, which may trigger an outbreak of the moths. She then says that `these data [on mast years], therefore, do not explain the cause of the severe acorn failures and contingent crash in mouse populations that might initiate... moth outbreaks'.