Non-native insects dominate daytime pollination in a high-elevation Hawaiian dryland ecosystem

Clare E. Aslan, Aaron B. Shiels, William Haines, Christina T. Liang

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Premise of the Study: Over one-third of the native flowering plant species in the Hawaiian Islands are listed as federally threatened or endangered. Lack of sufficient pollination could contribute to reductions in populations, reproduction, and genetic diversity among these species but has been little studied. Methods: We used systematic observations and manual flower treatments to quantify flower visitation and outcrossing dependency of eight native (including four endangered) plant species in a dryland ecosystem in Hawaii: Argemone glauca, Bidens menziesii, Dubautia linearis, Haplostachys haplostachya, Sida fallax, Silene lanceolata, Stenogyne angustifolia, and Tetramolopium arenarium. Key Results: During 576.36 h of flower observations, only insects visited the flowers. Out of all recorded flower visits, 85% were performed by non-native species, particularly the honeybee (Apis mellifera) and flies in the family Syrphidae. Some plant species received little visitation (e.g., S. angustifolia received one visit in 120 h of observation), whereas others were visited by a wide diversity of insects. The endangered plant species were visited by fewer visitor taxa than were the common native plant species. For six of the focal plant species, bagging of flowers to exclude pollinators resulted in significant reductions in seed set. Conclusions: The flower visitor community in this system, although heavily dominated by non-native insects, appears to be facilitating pollination for multiple plant species. Non-native insects may thus be sustaining biotic interactions otherwise threatened with disruption in this island ecosystem. This may be particularly important for the studied endangered plant species, which exhibit fewer partners than the more common plant species.

Original languageEnglish (US)
Pages (from-to)313-324
Number of pages12
JournalAmerican Journal of Botany
Issue number2
StatePublished - Feb 1 2019


  • Apis mellifera
  • Asteraceae
  • Haplostachys haplostachya
  • Silene lanceolata
  • Stenogyne angustifolia
  • Tetramolopium arenarium
  • disrupted mutualism
  • flower pollination treatments
  • flower visitation observations
  • island endemics

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics
  • Plant Science


Dive into the research topics of 'Non-native insects dominate daytime pollination in a high-elevation Hawaiian dryland ecosystem'. Together they form a unique fingerprint.

Cite this