A coat of many scents: Cuticular hydrocarbons in multitrophic interactions of fig wasps with ants

The fig fig wasp system of Ficus racemosa constitutes an assemblage of galler and parasitoid wasps in which tritrophic interactions occur. Since predatory ants (Oecophylla smaragdina and Technomyrmex albipes) or mostly trophobiont-tending ants (Myrmicaria brunnea) were previously shown to differentially use volatile organic compounds (VOCs) from figs as proximal cues for predation on fig wasps, we examined the response of these ants to the cuticular hydrocarbons (CHCs) of the wasps. CHC signatures of gallers were distinguished from those of parasitoids by the methyl-branched alkanes 5-methylpentacosane and 13-methylnonacosane which characterised trophic group membership. CHC profiles of wasp predator and wasp prey were congruent suggesting that parasitoids acquire CHCs from their prey; the CHC composition of the parasitoid Apocrypta sp 2 clustered with that of its galler host Apocryptophagus fusca, while the CHC profile of the parasitoid Apocryptophagus agraensis clustered with its galler prey, the fig pollinator Ceratosolen fusciceps. In behavioural assays with ants, parasitoid CHC extracts evoked greater response in all ant species compared to galler extracts, suggesting that parasitoid CHC extracts contain more elicitors of ant behaviour than those of plant feeders. CHCs of some wasp species did not elicit significant responses even in predatory ants, suggesting chemical camouflage. Contrary to earlier studies which demonstrated that predatory ants learned to associate wasp prey with specific fig VOCs, prior exposure to fig wasp CHCs did not affect the reaction of any ant species to these CHCs. (C) 2015 Elsevier Masson SAS. All rights reserved.

A Plant Needs Ants like a Dog Needs Fleas: Myrmelachista schumanni Ants Gall Many Tree Species to Create Housing

Hundreds of tropical plant species house ant colonies in specialized chambers called domatia. When, in 1873, Richard Spruce likened plant-ants to fleas and asserted that domatia are ant-created galls, he incited a debate that lasted almost a century. Alth

Seasonal changes in the trade-off among fig-supported wasps and viable seeds in figs and their evolutionary implications

What the real trade-off is among fig-supported wasps and the viable seeds of figs is heatedly debated in the studies of fig/fig wasp mutualism. In the present study, we collected wasp offspring (galls) and the viable seeds of premature fruits, and determined the foundress number in receptive fruits and all the types of wasps supported by Ficus racemosa L. during both the rainy and dry seasons in Xishuangbanna, China. The data show that the galls were positively correlated with viable seeds (n=32;r=0.74; P < 0.001) when the proportion of vacant female flowers (PVFF) was high, in April (68.0%), and were negatively correlated with viable seeds (n=48;r=-0.59; P < 0.05) when PVFF were limited (PVFF 42.6%) during a colder month (January). The mean foundress number per fruit during the colder months is significantly lower than during the warmer months (F-5,F-603 = 27.9; P < 0.001) and pollinator wasps can live longer during the colder months, During the colder months, the proportions of non-pollinators and wasp offspring are higher than those found during other months, whereas the proportion of viable seeds is not different compared with that of other months. Non-pollinator wasps tend to oviposit the female flowers that have been oviposited by pollinator wasps. The non-pollinators only negatively affect pollinator wasps and there is no obvious negative effect of non-pollinator wasps on viable seeds, so ovipositing by non-pollinator wasps will not result in the extinction of the figs during the process of evolution. The results of the present study indicate that figs can allow less foundresses to be in fruit cavities when PVFF are limited, which provides supporting evidence for the previous assumption that the plants have developed a mechanism to maintain a stable system because of the conflicts between the parties involved.

Exposición suMaría del sistema frenológico del doctor Gall

UANL

Key to the paper and social wasps of Central Europe (Hymenoptera: Vespidae)

A determination key to the Central European paper wasps (Polistinae – Polistes Latreille, 1802 – eight species) and social wasps (Vespinae – 11 species: Vespa Linnaeus, 1758 – one species, Vespula Thomson, 1869 – four species, Dolichovespula Rohwer, 1916 – six species) is given. Distribution and biotope requirements of all species in the Czech Republic and Slovakia are briefly mentioned. All social wasps occur more or less regularly in both countries. Four paper wasps are relatively common but four other species (Polistes atrimandibularis Zimmermann, 1930, P. sulcifer Zimmermann, 1930, P. associus Kohl, 1898, and P. gallicus (Linnaeus, 1767)) are very rare with the Czech Republic and/or Slovakia at the northern edge of their range.

Host niches and defensive extended phenotypes structure parasitoid wasp communities

Oak galls are spectacular extended phenotypes of gallwasp genes in host oak tissues and have evolved complex morphologies that serve, in part, to exclude parasitoid natural enemies. Parasitoids and their insect herbivore hosts have coevolved to produce diverse communities comprising about a third of all animal species. The factors structuring these communities, however, remain poorly understood. An emerging theme in community ecology is the need to consider the effects of host traits, shaped by both natural selection and phylogenetic history, on associated communities of natural enemies. Here we examine the impact of host traits and phylogenetic relatedness on 48 ecologically closed and species-rich communities of parasitoids attacking gall-inducing wasps on oaks. Gallwasps induce the development of spectacular and structurally complex galls whose species- and generation-specific morphologies are the extended phenotypes of gallwasp genes. All the associated natural enemies attack their concealed hosts through gall tissues, and several structural gall traits have been shown to enhance defence against parasitoid attack. Here we explore the significance of these and other host traits in predicting variation in parasitoid community structure across gallwasp species. In particular, we test the "Enemy Hypothesis,'' which predicts that galls with similar morphology will exclude similar sets of parasitoids and therefore have similar parasitoid communities. Having controlled for phylogenetic patterning in host traits and communities, we found significant correlations between parasitoid community structure and several gall structural traits (toughness, hairiness, stickiness), supporting the Enemy Hypothesis. Parasitoid community structure was also consistently predicted by components of the hosts' spatiotemporal niche, particularly host oak taxonomy and gall location (e.g., leaf versus bud versus seed). The combined explanatory power of structural and spatiotemporal traits on community structure can be high, reaching 62% in one analysis. The observed patterns derive mainly from partial niche specialisation of highly generalist parasitoids with broad host ranges (>20 hosts), rather than strict separation of enemies with narrower host ranges, and so may contribute to maintenance of the richness of generalist parasitoids in gallwasp communities. Though evolutionary escape from parasitoids might most effectively be achieved via changes in host oak taxon, extreme conservatism in this trait for gallwasps suggests that selection is more likely to have acted on gall morphology and location. Any escape from parasitoids associated with evolutionary shifts in these traits has probably only been transient, however, due to subsequent recruitment of parasitoid species already attacking other host galls with similar trait combinations.

Characterization of microsatellite markers for Sycoscapter nonpollinating fig wasps

We isolated 18 microsatellites from Sycoscapter australis, a nonpollinating fig wasp that develops in figs of Ficus macrophylla, and assessed their variability in 20 wasps. We further optimized nine of these loci for use in three other Sycoscapter species that develop in Ficus rubiginosa figs and assessed their variability in 47-140 wasps per species. These are the first microsatellites developed for nonpollinating fig wasps and show sufficient polymorphism to become important tools in evolutionary and genetical studies of Sycoscapter wasps.

Molecular dating and biogeography of fig-pollinating wasps

Figs and fig-pollinating wasps are obligate mutualists that have coevolved for over 60 million years. But when and where did pollinating fig wasps (Agaonidae) originate? Some studies suggest that agaonids arose in the Late Cretaceous and the current distribution of fig-wasp faunas can be explained by the break-up of the Gondwanan landmass. However, recent molecular-dating studies suggest divergence time estimates that are inconsistent with the Gondwanan vicariance hypothesis and imply that long distance oceanic dispersal could have been an important process for explaining the current distribution of both figs and fig wasps. Here, we use a combination of phylogenetic and biogeographical data to infer the age, the major period of diversification, and the geographic origin of pollinating fig wasps. Age estimates ranged widely depending on the molecular-dating method used and even when using the same method but with slightly different constraints, making it difficult to assess with certainty a Gondwanan origin of agaonids. The reconstruction of ancestral areas suggests that the most recent common ancestor of all extant fig-pollinating wasps was most likely Asian, although a southern Gondwana origin cannot be rejected. Our analysis also suggests that dispersal has played a more important role in the development of the fig-wasp biota than previously assumed. (C) 2009 Elsevier Inc. All rights reserved.