How pollinator visits are affected by flower damage and ants presence in Ipomoea carnea subs. fistulosa (Martius and Choise) (Convolvulaceae)?

This study aimed to evaluate the effects of florivory and of the patrolling ants associated to EFNs-extrafloral nectaries, on the frequency of floral visitors, using the specie Ipomoea carnea subs. fistulosa (Martius and Choise) in Caatinga area. The floral attributes of the species were characterized. The effect of florivoria on the frequency of visitors and the influence of the presence of ants associated with the NEFs on the pollinator visit rate were evaluated. The rate of natural florivoria was recorded and collected floral visitors and ants over eight months. The damage on floral structure and the presence of ants foraging in the flowers causes a decrease in the number of total visits. The results may be justified by the fact that the floral damage consisted in the loss of important floral attributes. These effects for Ipomoea carnea subs. fistulosa can affect reproductive success, since it is a self-incompatible species and depends on the activity of the pollinators for their fertilization to occur.

Evaluation of the symmetric effect of antagonists in the floral morphs of the distylic shrub Bouvardia ternifolia: a field study

<p><strong>Background:</strong> Heterostyly is a genetic polymorphism characterized by a system of sporophyte auto-incompatibility in which the plant populations show two (distyly) or three (tristyly) floral morphs. This reproductive system is known as a promoter of cross-pollination, assuming similar reproductive success between morphs.</p><p><strong>Hyphothesis:</strong> For this assumption to take place, the pollinators must respond in a similar manner to attraction floral traits in both morphs, maintaining a symmetric flow of pollen. We hypothesize that floral damage by antagonists should correspond to similarities or differences in atractiveness among floral morphs.</p><p><strong>Studied species:</strong> We tested this hypothesis in the distylous shrub <em>Bouvardia ternifolia</em> (Rubiaceae).</p><p><strong>Methods:</strong> we evaluated the magnitude of the nectar theft, foliar herbivory, and seed predation by assessing individual plants of both floral morphs throughout their flowering period (June-July 2015) under natural conditions. At the end of the flowering season, we quantified fruit and seed production.</p><p><strong>Results:</strong> The intensity of the herbivore and nectar thieves in this distylous population is similar between morphs, as well as the size of their floral displays. The number of seeds and fruits produced was also similar between morphs.</p><strong>Conclusions:</strong> Our study showed that selection pressures imposed by antagonists were similar to both floral morphs in the studied population of <em>Bouvardia ternifolia</em>.

Does dose-dependent petal damage affect pollen limitation in an annual plant?

Damage to flowers by herbivores, or florivory, can have direct impacts on gamete survival and can also indirectly affect fitness by reducing pollinator service. While recent studies have examined the impact of natural or artificial floral damage, very few researchers have manipulated both damage and pollen addition to see whether pollen limitation is enhanced by damage, and no workers, to my knowledge, have examined whether pollen limitation is dependent on the levels of florivory used. I used a pollen addition treatment and six levels of artificial floral damage to investigate whether damage increases pollen limitation and whether that pollen limitation becomes more severe with increasing numbers of petals damaged in Nemophila menziesii Hook. & Arn. I found that artificial floral damage that mimics natural florivore damage increases pollen limitation, and that this pollen limitation generally increased with increasing numbers of petals damaged. The treatment with the heaviest amount of damage did not suffer the most pollen limitation, perhaps because flowers in this treatment remained radially symmetric. These findings suggest that florivory may decrease pollen import through pollinator deterrence and could thus serve as a selective force on either floral or defense traits in outcrossing plant populations.