How much leaf area do insects eat? A data set of insect herbivory sampled globally with a standardized protocol

Revisiting florivory: an integrative review and global patterns of a neglected interaction

Florivory is an ancient interaction which has rarely been quantified due to a lack of standardized protocols, thus impairing biogeographical and phylogenetic comparisons. We created a global, continuously updated, open-access database comprising 180 species and 64 families to compare floral damage between tropical and temperate plants, to examine the effects of plant traits on floral damage, and to explore the eco-evolutionary dynamics of flower-florivore interactions. Flower damage is widespread across angiosperms, but was two-fold higher in tropical vs temperate species, suggesting stronger fitness impacts in the tropics. Flowers were mostly damaged by chewers, but neither flower color nor symmetry explained differences in florivory. Herbivory and florivory levels were positively correlated within species, even though the richness of the florivore community does not affect florivory levels. We show that florivory impacts plant fitness via multiple pathways and that ignoring this interaction makes it more difficult to obtain a broad understanding of the ecology and evolution of angiosperms. Finally, we propose a standardized protocol for florivory measurements, and identify key research avenues that will help fill persistent knowledge gaps. Florivory is expected to be a central research topic in an epoch characterized by widespread decreases in insect populations that comprise both pollinators and florivores.

A visual technique used by citizen scientists shows higher herbivory in understory vs. canopy leaves of a tropical forest

Citizen science (CS) initiatives can transform how some ecological data are collected. Herbivory is a fundamental ecological interaction, but herbivory rates in many natural systems are unknown due in part to lack of personnel for monitoring efforts. This limits our ability to understand broad ecological patterns relevant to herbivory. Fortunately, accurate and reliable visual estimation techniques for assessing herbivory could be amenable to CS approaches. In 2008, I developed a CS training initiative (the Million Leaf Project, MLP) to measure herbivory based on a seven-category visual assessment of leaf area removed (LAR). From 2010 to 2018, 394 citizen scientists assessed damage on 175,421 leaves to test the hypothesis that herbivory varies between understory and canopy leaves in a Peruvian tropical forest. In support of this hypothesis, the longitudinal CS data reveal that understory leaves consistently experience more herbivory than do canopy leaves on average (18.3% vs. 12.3%, P < 0.001), a difference that was consistent regardless of CS observer age. Furthermore, data integrity was high, even though younger participants showed some leaf selection bias. The MLP is based on a simple technique, intended to broaden public participation in ecological science, and applicable to any ecological system in which herbivory or leaf damage occurs.