Physalis angulata pollination after herbivory: the effects of herbivore damage on pollinator preference

Abstract

Pollination is the pinnacle of a plant’s life cycle. Progeny carry on paternal traits for higher fitness and survival while also maintaining genetic diversity among populations. While some species such as Physalis angulata can undergo self-pollination (“selfing”), outcrossing with other plants via pollinators still yields higher quality and number of seeds. Thus, the selection/avoidance of pollinators for certain plants is crucial in determining the health of future generations. This study examines pollinator preferences for plant flowers following herbivory. We created two groups of P. angulata, exposing one to Manduca sexta (a specialist herbivore for the Solanaceae family) and keeping the other as a control. Following substantial damage, the plants were introduced to the generalist pollinator Bombus impatiens, and interaction data were recorded for both groups. Analysis indicates a significant effect of herbivory on time elapsed until plants were first visited by pollinators. However, no impact of herbivory was seen on flower production or on pollinator preference regarding number of flowers visited, number of unique bumblebee visitors, and average visit duration per flower. We therefore conclude that herbivory by M. sexta on P. angulata does generate a significant effect on pollination as mediated by B. impatiens due to the increased time needed by pollinators to locate plants and flowers following herbivore damage. Expanding upon previously observed ecological relationships between herbivory and plant reproductive success, the novel mechanism of time to first visitation has potential applications for agricultural outputs as protection against pests could yield higher pollination rates during finite growing seasons.