title: Complex pollination of a tropical Asian rainforest canopy tree by flower-feeding thrips and thrips-feeding predators.
abstract: OBJECTIVE
  In tropical rainforests of Southeast Asia, a highly fecund thrips (Thrips spp.) responds rapidly to the mass flowering at multiple-year intervals characteristic of certain species such as the canopy tree studied here, Shorea acuminata, by feeding on flower resources. However, past DNA analyses of pollen adherent to thrips bodies revealed that the thrips promoted a very high level of self-pollination. Here, we identified the pollinator that contributes to cross-pollination and discuss ways that the pollination system has adapted to mass flowering.
  
  
  METHODS
  By comparing the patterns of floral visitation and levels of genetic diversity in adherent pollen loads among floral visitors, we evaluated the contribution of each flower visitor to pollination.
  
  
  RESULTS
  The big-eyed bug, Geocoris sp., a major thrips predator, was an inadvertent pollinator, and importantly contributed to cross-pollination. The total outcross pollen adhering to thrips was approximately 30% that on the big-eyed bugs. Similarly, 63% of alleles examined in S. acuminata seeds and seedlings occurred in pollen adhering to big-eyed bugs; about 30% was shared with pollen from thrips.
  
  
  CONCLUSIONS
  During mass flowering, big-eyed bugs likely travel among flowering S. acuminata trees, attracted by the abundant thrips. Floral visitation patterns of big-eyed bugs vs. other insects suggest that these bugs can maintain their population size between flowering by preying upon another thrips (Haplothrips sp.) that inhabits stipules of S. acuminata throughout the year and quickly respond to mass flowering. Thus, thrips and big-eyed bugs are essential components in the pollination of S. acuminata.
authors: Graduate School for International Development and Cooperation, Hiroshima University, 1-5-1 Kagamiyama, Higashi-Hiroshima 739-8529, Japan kondo@hiroshima-u.ac.jp.
authors: Toshiaki
authors: T
authors: Kondo
authors: Matsushiro, Tsukuba 305-0035, Japan.
authors: Sen
authors: S
authors: Nishimura
authors: Forestry Division, Japan International Research Center for Agricultural Sciences, 1-1 Ohwashi, Tsukuba 305-8686, Japan.
authors: Naoki
authors: N
authors: Tani
authors: Forest Research Institute Malaysia, 52109 Kepong, Selangor Darul Ehsan, Malaysia.
authors: Kevin Kit Siong
authors: KK
authors: Ng
authors: Forest Research Institute Malaysia, 52109 Kepong, Selangor Darul Ehsan, Malaysia.
authors: Soon Leong
authors: SL
authors: Lee
authors: Forest Research Institute Malaysia, 52109 Kepong, Selangor Darul Ehsan, Malaysia.
authors: Norwati
authors: N
authors: Muhammad
authors: Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan.
authors: Toshinori
authors: T
authors: Okuda
authors: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Ten-noudai, Tsukuba 305-8572, Japan.
authors: Yoshihiko
authors: Y
authors: Tsumura
authors: Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors: Yuji
authors: Y
authors: Isagi
mesh_terms: D000818:Animals; D053958:Dipterocarpaceae / Q000235:genetics / Q000469:parasitology / Q000502:physiology*; D035264:Flowers / Q000235:genetics / Q000469:parasitology / Q000502:physiology; D014644:Genetic Variation; D060005:Genotyping Techniques; D018895:Microsatellite Repeats / Q000235:genetics; D011058:Pollen / Q000235:genetics / Q000469:parasitology / Q000502:physiology; D054817:Pollination; D011156:Population Density; D065947:Rainforest; D012098:Reproduction; D036226:Seedlings / Q000235:genetics / Q000469:parasitology / Q000502:physiology; D012639:Seeds / Q000235:genetics / Q000502:physiology; D061149:Thysanoptera / Q000502:physiology*; D014197:Trees
keywords: Dipterocarpaceae; Shorea; Thysanoptera; big-eyed bug; general flowering; pollination; single-pollen genotyping; thrips; tropical rainforest