DOI: 10.5061/dryad.q83bk3jv5
title: Data from:Parasites and investment to host inflorescences in a fig tree-fig wasp mutualism

description: Most mutualisms are parasitized by third-party species that inflict costs
 on the mutualists. How such parasites affect mechanisms that help maintain
 mutualism stability is poorly understood, even in well-studied systems.
 Angiosperm plants tend to invest most resources in tissue that yields high
 net benefits. In mutualisms with plant hosts, a reduction in such
 investment can function as a key stability-promoting mechanism, such as in
 fig-wasp mutualisms. Here, uncooperative symbiont wasps that fail to
 pollinate incur ‘sanctions’ via reduced host investment to unpollinated
 figs, realized via fig abortion, killing all wasp offspring, or via
 elevated offspring mortality within unaborted figs. We experimentally
 exposed host Ficus racemosa figs to parasitic wasps Sycophaga fusca, which
 convert fig flowers into offspring without benefitting host trees, with or
 without uncooperative (pollen-free) or cooperative (pollen-laden) symbiont
 pollinator wasps Ceratosolen fusciceps. Pollen-free C. fusciceps were
 still able to convert fig flower ovaries into wasp offspring, whereas
 those naturally pollen-laden were prevented from reproducing by
 experimental manipulation. Independent of the effects of pollination and
 reproduction by pollinators, increased exposure to S. fusca parasites
 resulted in reduced rates of fig abortion and gall failure in unaborted
 figs. Although S. fusca converts flower ovaries that could otherwise
 become beneficial pollinator offspring or fig seeds into parasite
 offspring, figs with intermediate levels of parasite exposure received
 high levels of investment. Our results suggest that S. fusca parasite
 oviposition/larval activities can result in host trees boosting investment
 in figs, even when this may counter the tree’s interests. We suggest that
 oviposition/larval activity by these parasites may mimic the biochemical
 pathways of pollinator gall formation and seed production.
description: # Parasites and investment to host inflorescences in a fig tree-fig wasp
 mutualism Dataset DOI: [10.5061/dryad.q83bk3jv5](10.5061/dryad.q83bk3jv5)
 ## Description of the data and file structure This study shows that in the
 fig–wasp mutualism, parasitic wasps (*Sycophaga fusca*), which don’t
 benefit the host tree, can still trigger increased investment by the fig
 tree in developing figs. Surprisingly, this happens even when cooperative
 pollinators are absent, suggesting that the parasites may mimic signals
 usually produced by beneficial partners, potentially undermining the
 tree’s mechanisms for maintaining mutualism stability. All missing data
 indicated as NA. Chen et al. 2025. Data sheet column headings: Column
 headings are the same for all three data sheets: Ex_1.csv, Ex_2.csv and
 Ex_3.csv, data for experiments 1, 2 and 3, respectively. * **Row** –
 arbitrary row number. Data for each row are from a single fig. -
 **Treatment** – experimental treatment to individual figs (see methods in
 publication for details). * **Tree** – tree on which the experimental fig
 resided (see methods and Appendix s1. Table S1 for details). - **SF** –
 the number of parasite wasps S. fusca to which each experimental fig was
 exposed. * **Poll** – the number of C. fusciceps foundresses
 experimentally introduced into each fig. - **Pollen** – whether
 experimental figs received pollen or not. * **SF_gall** – whether flower
 ovary galling by parasites occurred or not - **Poll_gall** – whether
 flower ovary galling by pollinator foundresses occurred or not. *
 **Abort** – whether a fig aborted or not prior to maturity. -
 **Abortcode** – binary code of whether a fig aborted (1) or not (0). *
 **N_SF_M** – number of S. fusca male offspring produced in a fig -
 **N_SF_F** – number of S. fusca female offspring produced in a fig *
 **N_pol_M** – number of pollinator C. fusciceps male offspring produced in
 a fig. - **N_pol_F** – number of pollinator C. fusciceps female offspring
 produced in a fig * **Galls** – number of flowers in a fig converted into
 wasp galls (S. fusca + C. fusciceps). - **Seeds** – number of seeds
 produced in a fig * **Vacant** – number of flowers that failed to produce
 either a seed or to be converted into a wasp gall. - **Tot_flowers** –
 total number of flowers within a fig * **Tot_SF** – the total number of S.
 fusca offspring produced in a fig. - **Tot_poll** – the total number of
 pollinator C. fusciceps offspring produced in a fig. * **Totwasps** – the
 total number of wasps (S. fusca + C. fusciceps) produced in a fig. -
 **Gall_rate** – the proportion of all flowers galled by wasps. *
 **Gall-failure** – the proportion of all flowers galled by wasps that
 failed to produce an adult wasp offspring (see methods for details). -
 **Occupancy** – the proportion of all flowers that were either galled by
 wasps or produced seeds (see methods for details).