title: Flower-Visiting Insects and Phenology of Lippia alba (Lamiales: Verbenaceae): Floral Color Changes and Environmental Conditions as Cues for Pollinators.
abstract: Lippia alba (Mill.) N.E. Br. ex Britton & P. Wilson (Verbenaceae) is a herbal aromatic shrub with medicinal properties. Natural populations of this species are allogamous and self-incompatible. Therefore, this plant species relies on pollinators to outcross and maintain the genetic variability. Here, we investigated the floral phenology, pollen morphology, the floral visitor entomofauna, and the influence of climatic factors on the frequency of visits in L. alba flowers. The study was conducted at Federal University of Juiz de Fora Plant Experimental Area, southeast Brazil. The flowering of L. alba occurred throughout the whole year. The anthesis is diurnal and lasts 5 d. The nectar guide was visible from the onset of flowering until the third day. Pollen grains were classified as isopolar, oblate spheroidal, three-colporate (rare, four-colporate), surface tectate-perforate, and endoaperture lalongate, with median constriction. Insects from the order Hymenoptera were the most frequent visitors observed, followed by Lepidoptera, Thysanoptera, Diptera, and Hemiptera-Heteroptera. The preference of insects for flowers with nectar guides shows that the color is likely to be an important visual trait to increase the frequency of visits. Moreover, the climate variables temperature, relative humidity, wind speed, and light were important to define the composition of the most frequent floral visitors.
authors.affiliation: 1Programa de Pós-graduação em Ecologia, Universidade Federal de Juiz de Fora, 36036-900 Juiz de Fora, Minas Gerais, Brazil (danielevenancio@gmail.com).
authors.forename: Daniele de Fátima Alves
authors.initials: DFA
authors.lastname: Venâncio
authors.affiliation: 4Departamento de Botânica, Universidade Federal de Juiz de Fora, 36.036-900, Minas Gerais, Brazil (luizi.ponzo@ufjf.edu.br), and.
authors.forename: Lyderson Facio
authors.initials: LF
authors.lastname: Viccini
authors.affiliation: 5Departamento de Zoologia, Universidade Federal de Juiz de Fora, CEP 36036-900, Juiz de Fora, MG, Brazil (fabio.prezoto@ufjf.edu.br).
authors.forename: Andrea Pereira
authors.initials: AP
authors.lastname: Luizi-Ponzo
authors.affiliation: 5Departamento de Zoologia, Universidade Federal de Juiz de Fora, CEP 36036-900, Juiz de Fora, MG, Brazil (fabio.prezoto@ufjf.edu.br).
authors.forename: Fábio
authors.initials: F
authors.lastname: Prezoto
keywords: climatic factor; insect; pollen grain; pollinator