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ABSTRACT Most plant communities worldwide include exotic plants, which did not evolve with local organisms. The central goal of this study is to test if native organisms expanding their interactions to novel hosts are usually generalists or specialists. Here we studied new associations between hummingbirds, flower mites andMusa velutina(Musaceae), an exotic plant native to northeast India currently invading lowland forests in Costa Rica. Hummingbirds are pollinators, but flower mites feed on nectar without contributing to pollen transfer. Flower mites hitch rides on hummingbird beaks to colonize new flowers. To determine the original diet breadth of hummingbird and flower mite species, we assembled hummingbird and flower mite interactions at La Selva Biological Station. We identified four hummingbird species visitingMusa velutina. DNA barcode analyses identified only one species of flower mite colonizing flowers ofM. velutina. All new associations withM. velutinainvolved generalist hummingbird and flower mite species.Musa velutinadisplays both male and female flowers. Although flowers of both sexes were equally visited by hummingbirds, mites were 15 times more abundant in male than in female flowers. We hypothesize that this is the result of constant immigration coupled with mite population growth. Only half of the mites hitching rides on hummingbird beaks emigrate to newly opened flowers. Our results show thatM. velutinaintegration to a plant community occurs mainly by establishing interactions with generalists.
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Solitary Bees Acquire and Deposit Bacteria via Flowers: Testing the Environmental Transmission Hypothesis Using Osmia lignaria , Phacelia tanacetifolia , and Apilactobacillus micheneri
ABSTRACT Microbial environmental transmission among individuals plays an important role in shaping the microbiomes of many species. Despite the importance of the microbiome for host fitness, empirical investigations on environmental transmission are scarce, particularly in systems where interactions across multiple trophic levels influence symbiotic dynamics. Here, we explore microbial transmission within insect microbiomes, focusing on solitary bees. Specifically, we investigate the environmental transmission hypothesis, which posits that solitary bees acquire and deposit their associated microbiota from and to their surroundings, especially flowers. Using experimental setups, we examine the transmission dynamics ofApilactobacillus micheneri, a fructophilic and acidophilic bacterium, between the solitary beeOsmia lignaria(Megachilidae) and the plantPhacelia tanacetifolia(Boraginaceae). Our results demonstrate that bees not only acquire bacteria from flowers but also deposit these microbes onto uninoculated flowers for other bees to acquire them, supporting a bidirectional microbial exchange. We therefore find empirical support for the environmental transmission hypothesis, and we discuss the multitrophic dependencies that facilitate microbial transmission between bees and flowers.
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- PAR ID:
- 10610363
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecology and Evolution
- Volume:
- 15
- Issue:
- 4
- ISSN:
- 2045-7758
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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