Florivory and floral larceny by fly larvae decrease nectar availability and hummingbird foraging visits at Heliconia (Heliconiaceae) flowers

Abstract

Insect larvae inhabit the corolla tubes of some Heliconia species (Heliconiaceae). In this study, we present the first evidence of the influence of these larvae on the pollination ecology of Heliconia plants. We provide experimental evidence that the flowers of Heliconia spathocircinata infested by flies have less nectar for pollinators and received fewer visits by hummingbird pollinators, in comparison with uninfested flowers.

Floral antagonists counteract pollinator‐mediated selection on attractiveness traits in the hummingbird‐pollinatedCollaea cipoensis(Fabaceae)

“…Although hummingbirds prefer ornitophilous species, they act as generalist visitors depending on the ecological context (Dalsgaard et al . ) and may be very sensitive to plant resources ( e.g., avoiding flowers with high nectar‐robbing levels; Irwin & Brody , Missagia & Alves ). Indeed, hummingbirds appear to be less specialized and to visit more non‐ornitophilous plants in dry, seasonal, and open habitats (Arizmendi & Ornelas , Dalsgaard et al .…”

“…() found that nectar‐robbers indirectly affect female fitness of the hummingbird‐pollinated Ipomopsis aggregata via changes in pollination success as robbing itself did not reduce fruit and seed production in hand‐pollinated flowers. In a recent study in the Atlantic forest in Brazil, Missagia and Alves () reported that dipteran larvae‐infected flowers of Heliconia spathocircinata received fewer visits by hummingbird pollinators than uninfected flowers. Either way, we here not only demonstrate that offspring production is significantly reduced by a high incidence of floral antagonists, but also that this process exerts negative selective pressures on floral attractiveness traits.…”

“…In this regard, the direct contribution of hummingbirds to plant reproduction may be low, even when they are the most frequent visitors (Maruyama et al 2012, Watts et al 2012. Although hummingbirds prefer ornitophilous species, they act as generalist visitors depending on the ecological context (Dalsgaard et al 2009) and may be very sensitive to plant resources (e.g., avoiding flowers with high nectar-robbing levels; Irwin & Brody 1998, Missagia & Alves 2017. Indeed, hummingbirds appear to be less specialized and to visit more non-ornitophilous plants in dry, seasonal, and open habitats (Arizmendi & Ornelas 1990, Dalsgaard et al 2009, Rodrigues & Rodrigues 2014.…”

“…For example, Irwin et al (2015) found that nectar-robbers indirectly affect female fitness of the hummingbird-pollinated Ipomopsis aggregata via changes in pollination success as robbing itself did not reduce fruit and seed production in hand-pollinated flowers. In a recent study in the Atlantic forest in Brazil, Missagia and Alves (2017) reported that dipteran larvae-infected flowers of Heliconia spathocircinata received fewer visits by hummingbird pollinators than uninfected flowers.…”

Consequences of multiple flower–insect interactions for subsequent plant–insect interactions and plant reproduction

“…Floral antagonists also alter flower traits. Florivory changes floral symmetry (McCall, 2008), volatile emissions (Lucas-Barbosa et al, 2011), nectar guides (Botto-Mahan and Ojeda-Camacho, 2000), rewards (Krupnick et al, 1999;Missagia and Alves, 2017), display size (Ashman and Penet, 2007;Liao et al, 2013), and resistance traits (McCall, 2006;Kaczorowski et al, 2014;Boyer et al, 2016), all of which could affect the preference of other floral antagonists or mutualists (e.g., Soper Gorden and . For example, florivory in Pedicularis gruina reduces the number of pollinator visits (Liao et al, 2013), further supporting the need to study interactions in a community context.…”