Evidence for damaged plant tissue as the mechanism behind the aggregation of Altica subplicata on one of its primary host plants, Salix cordata.

Abstract

Aggregation behavior of Altica subplicata on one of its host plants, Salix cordata, has been previously documented. An aggregation pheromone was suggested as a possible mechanism. The purpose of this study was to investigate the mechanism behind the aggregations. Field studies were carried out whether the number of A. subplicata attracted to a treatment were compared. Treatments consisted of mechanically damaged S. cordata, S. cordata with beetles, beetles, and an undamaged S. cordata. A significantly greater number of A. subplicata was attracted to the damaged plant than any other treatment. This finding suggests that the beetles may be attracted to volatile chemical released from the host plant during feeding. Further investigation was made to see if such a response was found among other primary and secondary host plants. The findings from the second experiment indicate that this response may be a species specific response to only S. cordata, but further investigation is warranted.