Putting your eggs in several baskets: oviposition in a wasp that walks between several figs

Abstract

The interaction between figs (Ficus spp., Moraceae) and their pollinator fig wasps (Hymenoptera: Agaonidae) is an obligate mutualism, but females of dioecious fig trees exploit fig wasps without providing rewards. Figs are closed inflorescences that typically trap pollinator females after entry, but some fig wasp species can re-emerge (although wingless) and subsequently oviposit in and pollinate further figs. Using glasshouse populations, we examined the sex ratios and clutches laid by single foundresses of Kradibia tentacularis (Grandi) in their first and subsequent male figs of Ficus montana Blume, and how the probability of emergence and entering a second fig varied between seasons. A maximum of four figs were entered by any one foundress. Wingless foundresses were able to locate and enter figs up to 60 cm from the first fig they entered, but the probability of entry declined sharply with distance from that fig. The foundresses that re-emerged produced slightly higher adult offspring totals than those that failed to re-emerge. Clutch sizes of a single foundress in its first fig equalled those in all the subsequent figs combined, with clutch size per fig decreasing when more figs were entered. Smaller clutches had less female-biased sex ratios. Figs were more numerous in summer than in winter, but the proportion of figs entered by only wingless foundresses remained unchanged.Movement between figs increases pollinator reproductive success in male figs, thereby encouraging foundresses that encounter a female tree to also move between and pollinate several female figs.

A comparison of pollinator fig wasp development in figs of Ficus montana and its hybrids with Ficus asperifolia

“…The plant population comprised mainly cuttings from the source plants originally obtained from the wild population, supplemented by second-generation plants grown from seed. Kradibia tentacularis females actively pollinate the figs of F. montana and routinely re-emerge from both male and female figs, allowing them to pollinate and lay eggs in several figs (Suleman et al, 2013a).…”

Interactions between pollinator and non‐pollinator fig wasps: correlations between their numbers can be misleading

“…These (wingless) foundresses are able to locate and enter figs up to 60 cm from the first fig they enter (Suleman et al . ). The NPFW Sycoscapter sp.…”

“…Pollinating females of K. tentacularis seek out figs at the receptive stage, enter, attempt to oviposit and pollinate and then either die or leave in an attempt to oviposit in another fig (Suleman 2007). These (wingless) foundresses are able to locate and enter figs up to 60 cm from the first fig they enter (Suleman et al 2013c). The NPFW Sycoscapter sp.…”

Female figs as traps: Their impact on the dynamics of an experimental fig tree-pollinator-parasitoid community

“…Pollinating females of K. tentacularis seek out the figs at the receptive stage, enter them, oviposit, pollinate and then either die or leave the fig in an attempt to oviposit in another fig (Suleman, 2007). Wingless foundresses (passing through the ostiole physically removes the wings of female fig wasps) are able to locate and enter figs up to 60 cm from the first fig they enter (Suleman et al, 2013c). The NPFW Sycoscapter sp.…”

“…K. tentacularis foundresses can reemerge from figs and this allows them to oviposit in several figs on the same plant. Foundresses entering their second figs lay smaller clutches, which reduces competition for oviposition sites and weakens the impact of foundress numbers on offspring sex ratios (Raja et al, 2008a;Suleman et al, 2013c).…”