Diffuse Coevolution between Two Epicephala Species (Gracillariidae) and Two Breynia Species (Phyllanthaceae)

Abstract

The diffuse coevolution between two moth species (Epicephala lativalvaris and E. mirivalvata) and two plant species (Breynia fruticosa and B. rostrata) is reported based on field observations and indoor experiments conducted in Hainan and Fujian, China. Study results showed that the two Epicephala species jointly pollinated the two Breynia species, which led to a unique obligate pollination mutualism of two−to−two species specificity. A single Epicephala larva exclusively fed on seeds of host plants and developed to maturity by consuming all six seeds of each fruit, whereas a fraction of intact fruits were left to ensure the reproduction of plants within the whole population. Larvae of the two Epicephala species are competitive for resources; the population of E. mirivalvata is much smaller than that of E. lativalvaris, which has resulted from the differences in the female ovipositor structures and oviposition mode. The life history of Epicephala species highly coincides with the phenology of Breynia plants, and different phenology of B. fruticosa resulted in the different life history of the two Epicephala species in Hainan and Fujian. The natural hybridization of two host plants, possibly induced by the alternate pollination of two Epicephala species, is briefly discussed.

Non-congruent colonizations and diversification in a coevolving pollination mutualism on oceanic islands

“…Alternatively, competition between two pollinators may result in displacement of one species, or divergence in the plant may be accompanied by coevolution with different pollinators. Local coexistence rspb.royalsocietypublishing.org Proc R Soc B 280: 20130361 of two distantly related Epicephala species on a single leafflower species has been reported in Asia [30,82]. Because host-shifts may potentially be a mechanism of diversification mediated by coevolution, data on their frequency, ecology and selective consequences in this and similar systems may reveal much about how coevolving clades diversify.…”

A Novel, Enigmatic Basal Leafflower Moth Lineage Pollinating a Derived Leafflower Host Illustrates the Dynamics of Host Shifts, Partner Replacement, and Apparent Coadaptation in Intimate Mutualisms

“…For instance, floral odor blends emitted by leafflowers are known to vary both among species within a clade (Okamoto et al 2007) as well as among clades (Okamoto et al 2013), and these blends are responsible for mediating host recognition by female moths. More derived Epicephala females possess a sclerotized ovipositor, which is used in most cases for laying eggs inside ovary tissue of leafflower flowers rather than on the external surface of the carpels (Kawakita and Kato 2009, 2016; but see Zhang et al 2012 b ). Finally, processes such as biogeographic isolation of some pairs of subclades (such as Madagascar Phyllanthus and their Epicephala ) may reduce the likelihood of host shifts among subclades.…”

Pollinator sharing and gene flow among closely related sympatric dioecious fig taxa

“…The extent to which plant taxa in an obligate system maintain the identity of their floral signature, especially among sympatric closely related taxa, may be critical to guarantee the reproductive isolation of plants. Further, the occurrence of multiple pollinators per host, pollinator sharing and pollinator shift events have been reported in many obligate pollination systems [6,[19][20][21]. Temporal isolation [22] or habitat preference [23] have also been mentioned as mechanisms to maintain reproductive isolation.…”