Ficus curtipes belongs to the monoecious subgenus Urostigma, subsection Conosycea. This species is widely distributed in China, Malaysia, India, and Thailand. Growing up to 5–10 m, it occurs naturally in Xishuangbanna's tropical forests. Previous studies have shown that Ficus curtipes Corner is a passively-pollinated fig tree species with two internally-ovipositing ‘non-pollinating’ fig wasps (NPFWs) that can pollinate its figs.
Prof. YANG Darong and his research group of Xishuangbanna Tropical Botanical Garden (XTBG) have engaged in the studies on interrelationships between figs and fig wasps for many years. In a recent article, they described studies of the biology of the ‘non-pollinating’ fig wasps and their relationship to the tree's agaonid pollinator. The study was conducted at the Xishuangbanna Tropical Botanical Garden (101°15'E, 21°55'N, at about 555 m a.s.l.)
Specifically they asked: (i) Is egg maturation in ‘non-pollinating’ fig wasps pro-ovigenic, as in agaonids and do they contain the same number of eggs as the agaonid associated with F. curtipes? (ii) Are they of a similar body size and are their ovipositors of a similar length to those of the tree's agaonid pollinator and do they insert their ovipositors in a similar way? (iii) Do all three internally-ovipositing fig wasps prefer to oviposit in short-styled flowers? and (iv) What is the relationship between the NPFWs and the agaonid: are the NPFWs gallers, inquilines or parasitoids?
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 indicated that both NPFWs were inquilines under the widely-used terminology in the fig wasp literature, because they utilized 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 were better described as secondary gallers that modified galls previously generated by the pollinators and killed the primary gallers.
The study entitled “Secondary galling: a novel feeding strategy among ‘non-pollinating’ fig wasps from Ficus curtipes” has been published online in Ecological Entomology, DOI: 10.1111/een.12030
