Secondary galling: a novel feeding strategy among ‘non-pollinating’ fig wasps from Ficus curtipes
Correspondence: Yan-Qiong Peng, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 88 Xuefu Road, Kunming, 650223, China. E-mail: firstname.lastname@example.org
- The interaction between pollinator fig wasps (Agaonidae) and their host fig trees (Ficus) is a striking example of an obligate plant–insect mutualism, but figs also support numerous ‘parasites’ of the mutualism. Female agaonids (foundresses) lay their eggs in shorter-styled flowers, whereas longer-styled flowers produce seeds. A few ‘non-pollinating’ fig wasps (NPFWs) can also enter figs to oviposit
- Fig wasp oviposition site choice and larval biology in figs of an Asian monoecious species, Ficus curtipes Corner, were recorded where two NPFW species oviposit inside the figs, such as the agaonid.
- Eupristina sp. agaonids chose flowers in proportion to their availability, rather than preferring to oviposit in shorter-styled flowers. Diaziella yangi van Noort & Rasplus and Lipothymus sp. (Pteromalidae) foundresses followed Eupristina sp. into receptive figs and laid their eggs entirely in flowers that already contained pollinator eggs. This indicates that both NPFWs are inquilines under the widely-used terminology in the fig wasp literature, because they utilise galls generated by the pollinators. However, their adult bodies and galls were larger than those of the pollinators, showing that they independently stimulate ovule growth. These species are better described as secondary gallers that modify galls previously generated by the pollinators and kill these primary gallers.
- Use of the term ‘inquiline’ among NPFWs inadequately and often inappropriately describes their biology. No known NPFWs are inquilines in the strict sense that they do not harm their hosts. ‘Primary gallers’, ‘secondary gallers’, ‘seed predators’, and ‘parasitoids’ describe their biology more accurately.