Mating Frequency and Fecundity in Agrilus anxius Buprestidae) (Coleoptera:.

Bronze birch borers (Agrilus anxius Gory) (Coleoptera: Buprestidae), a key pest of birches in North America, have the potential to be a major threat to Eurasian birch forests. Therefore, the consequences of single versus multiple mating on the longevity, fecundity and fertility of female A. anxius were examined. There were three treatments: females observed mating one time and 1) then housed alone, 2) kept with their mate, and 3) females paired and housed with a randomly chosen male. Another group of females were observed mating once, and then dissected, 47 of 48 of them had received spermatophores. Weight and longevity of females did not differ among mating treatments. Fecundity, but not fertility, was positively correlated with longevity in all treatments. A high percentage of females in all three mating treatments laid eggs, and there was not a significant difference among treatments. The fecundity of females that laid eggs also did not differ among treatments. These results suggest that a single successful mating may be sufficient to ensure maximal fecundity for females, and that potential for failure of any mating is low. However, there is no apparent cost to multiple mating. Thus, multiple mating may increase fecundity for female bronze birch borers. Our results suggest that laboratory rearing protocols need not ensure females mate multiple times. At the population level, our results suggest that a mate-finding Allee effect at low population densities is unlikely. We also compare the results to an earlier study with the emerald ash borer, Agrilus planipennis Fairmaire. [ABSTRACT FROM AUTHOR]