Molecular approaches identify known species, reveal cryptic species and verify host specificity of Chinese Philotrypesis (Hymenoptera: Pteromalidae)

Abstract

Philotrypesis, a major component of the fig wasp community (Hymenoptera: Pteromalidae), is a model taxon for studying male fighting and mating behaviour. Its extreme sexual dimorphism and male polymorphism render species identification uncertain and in-depth research on its ecology, behaviour and other evolutionary topics challenging. The fig wasps' enclosed habitat within the syconia makes their mating behaviour inaccessible, to the extent of matching conspecific females and males. In this study, we combine morphological and molecular analyses to identify species of Philotrypesis sampled from south China and to associate their extraordinarily dimorphic genders and labile male morphologies. Morphological evaluations of females identify 22 species and 28 male morphs. The mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2 data detect 21 species using females, and 15 species among the males. Most of the males match the species as delimited by females. Both markers reveal cryptic species in P. quadrisetosa on Ficus vasculosa. Most species of wasps live on one species of fig but three species co-occur in two hosts (F. microcarpa and F. benjamina), which indicates host switching.

Molecular species delimitation of a symbiotic fig-pollinating wasp species complex reveals extreme deviation from reciprocal partner specificity

“…None of the currently used nuclear markers achieve the widespread utility of favoured mtDNA markers like COI and cytb. However, an internal transcribed spacer region (ITS2) of rDNA has recently been proposed as a useful nuclear barcoding marker for animals [41-44]. …”

Plant geographic phenotypic variation drives diversification in its associated community of a phytophagous insect and its parasitoids

“…Indeed within Ficus , intra-specific fig size variation is widespread and is spatially structured in at least some species [21, 22]. More generally, in many plant species, the size of some organs or structures, for instance the size of acorns [17], varies geographically and provides a series of situations in which processes analogous to the one documented here could apply.…”

“…Seven published Philotrypesis COI sequences, 3 from Hainan Island and 4 from Fujian were also included in the analysis [22, 23]. We built COI neighbor joining trees for the two genera.…”

First record of an apparently rare fig wasp feeding strategy: obligate seed predation

“…It has also been introduced into Brazil, Florida, Puerto Rico, and Hawaii (Beardsley, ; Farache et al , ; R. Wang and S. G. Compton, unpublished). This species may also utilise another fig tree host, Ficus benjamina L. (Zhou et al , ). Little is recorded about its biology, other than that females were observed to oviposit into figs that had been pollinated weeks earlier, which suggested that it may be a parasitoid, because gall‐forming species usually oviposit earlier (Compton, ; Chen et al , ).…”