Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Chheang, Pisal [1], Hembry, David H. [2], Yao, Gang [3], Luo, Shixiao [4].

Diversity and network structure of specialized pollination of leafflower trees (Phyllanthaceae: Glochidion) by leafflower moths (Lepidoptera: Epicephala) in tropical Southeast Asia (Cambodia).

Mutualistic associations between leafflower trees (Phyllanthaceae: Glochidion) and leafflower moths (Gracillariidae: Epicephala ) have previously been reported from the Asia-Pacific region. However, the pollination ecology and network structure of this interaction is poorly understood in tropical Asia, where this mutualism is most species-rich at both regional (~200 spp.) and local (< 9 spp.) scales. Here we report investigations of pollination biology, species-specificity, and network structure of Glochidion-Epicephala interactions at six sites in tropical Southeast Asia (Cambodia). Through nocturnal observations and fruit dissections, we find that at least three and likely five Glochidion species in Cambodia are pollinated by seed-parasitic leafflower moths. We find no evidence that any of these leafflower moths are non-mutualistic parasites, despite known examples of such parasites of this mutualism elsewhere in Asia. While the presence of a single larva in a fruit results in only a fraction of seeds being consumed, the presence of more than one larva per fruit—a frequent occurrence in some species—can result in almost all seeds within the fruit being infested. Multilocus molecular phylogenetic analysis indicates that there are five different minimally monophyletic leafflower moth clades (candidate moth “species”), each of which pollinates a unique Glochidion host species. Indeed, we find that the regional leafflower-leafflower moth network is highly reciprocally specialized and significantly modular at both local and regional scales. The regional network is also characterized by low connectivity. Interestingly, we find that each host plant species has a unique pollinator species across all sampled sites in Cambodia. Our results indicate that in its center of diversity in tropical Asia this system is an obligate pollination mutualism as previously described at the global margins of its distribution, and is extremely specialized. These findings provide insights into the processes that generate and maintain biodiversity and maintain mutualism stability in plant-insect interactions in this biodiversity hotspot.

1 - University of Chinese Academy of Sciences, South China Botanical Garden, Beijing, China
2 - University of Arizona, Tucson, USA
3 - South China Agricultural University, Guangzhou, China
4 - South China Botanical Garden, Guangzhou, China

Keywords:
Glochidion
Epicephala
mutualism
leafflower-leafflower moth
Phyllanthaceae
Southeast Asia
network property.

Presentation Type: Oral Paper
Session: SYMB3, Symbioses: Plant, Animal and Microbe Interactions 3
Location: /
Date: Thursday, July 22nd, 2021
Time: 3:45 PM(EDT)
Number: SYMB3004
Abstract ID:203
Candidate for Awards:None