Non‐pollinating Fig Wasps Decrease Pollinator and Seed Production in Ficus andicola (Moraceae)

Abstract

Fig trees (Ficus spp.) and Agaonine fig-wasps participate in an obligate mutualism. Fig wasps can only develop within fig inflorescences (syconia) and they are the only organisms capable of pollinating fig flowers.Other non-pollinating wasps that lay eggs by inserting their ovipositors from the outside can also develop in syconia. These parasitic wasps may be parasitoids of either pollinating or other nonpollinating wasps, or form galls in fig flowers or other tissues. Depending on this interaction, parasitic wasps may have various effects on the production of pollinating wasps and seeds. Wasps in the genus Idarnes, which parasitize New World figs (subgenus Urostigma), have an effect on wasp production but not on seed production. Heterandrium spp., which have short ovipositors and lay on external flowers, are infrequent and no effect on seed production has been documented. In the Colombian Andes, Idarnes spp. and Heterandrium spp. are the most frequent parasites of the Ficus andicola -Pegoscapus sp. mutualism, affecting 62 and 43 percent of syconia, respectively. Controlling for other factors that influence wasp and seed production, such as number of foundresses, syconium size and tree, we found that Idarnes reduced pollinator production by almost half but did not reduce seed production, whereas Heterandrium reduced seed production by 40 percent, and marginally affected pollinator production. Our results provide the first clear documentation of Heterandrium spp. impact on fig seed production. Whether the relative abundance of this genus is a generalized phenomenon in montane forest remains to be determined.Abstract in Spanish is available in the online version of this article.

A trophic cascade induced by predatory ants in a fig–fig wasp mutualism

“…O. smaragdina appears to reduce oviposition of P. mayri by both direct predation and disturbance, which may indirectly benefit the figs and pollinators. Gall makers, such as P. mayri and P. testacea , lay eggs in the female fig flowers (Wang & Zheng ; Wang, Sun & Zheng ) and analogous galler species in other fig–fig wasp systems having also been reported to reduce pollinating wasp and/or fig seed production (Kerdelhue & Rasplus ; Cardona, Kattan & de Ulloa ).…”

“…O. smaragdina appears to reduce oviposition of P. mayri by both direct predation and disturbance, which may indirectly benefit the figs and pollinators. Gall makers, such as P. mayri and P. testacea (Kerdelhue & Rasplus 1996;Cardona, Kattan & de Ulloa 2012).…”

How to be an ant on figs

“…) reports that he has observed figs unexpectedly covered in numerous long hairs, which on closer inspection turned out to be the ovipositors of NPFWs that had been preyed upon by ants. The production of NPFWs has been negatively correlated with the presence of ants in several fig species (Compton and Robertson, 1988;Zachariades, 1994;Schatz et al, 2006;Harrison, 2013) and the abundance of NPFWss is often strongly negatively correlated with pollinator production (Kerdelhué and Rasplus, 1996;Wei et al, 2005;Tzeng et al, 2008;Ma et al, 2009;Cardona et al, 2012). Interestingly, some NPFWs, such as the Sycophaga species on F. racemosa (Bain, pers.…”

The enemy of my enemy is my friend: Nematode infection of pollinating and non-pollinating fig wasps has net benefits for the fig-fig wasp pollination mutualism

“…In Depending upon the species, NPFWs parasitize developing seeds, pollinators, or other nonpollinators, or induce galls within the fig wall in close proximity to developing pollinators (West et al 1996, Segar et al 2018. Thus, many NPFW species have negative fitness impacts on the fig-pollinator mutualism (West and Herre 1994, Cardona et al 2013, Jansen-González et al 2014, Borges 2015.…”