Description
1. Quantitative food web analyses can provide insights into the specificity of consumer species such as herbivores, parasites, and parasitoids. Understanding such patterns of specificity can help forecast the potential benefits and risks of biological control agents being considered for introduction against invasive species. 2. The avian vampire fly, Philornis downsi (Diptera: Muscidae), is a neotropical bird parasite that is invasive in the Galapagos Islands, causing substantial mortality of endemic bird species. We used a novel in-field experimental food web approach within the native range of P. downsi in western Ecuador to test the hypotheses that pupal parasitoids known to attack P. downsi specialize on members of the genus Philornis, which occur only in bird nests. Since the pupae of other fly species are challenging to locate in the field, we developed a method to deploy pupae of non-Philornis fly species adjacent to bird nests to assess specificity of the parasitoids more accurately. We used two complementary indices to assess specificity: Resource Range (RR), which evaluates the breadth of host use, and Pair Difference Index (PDI), which evaluates interaction strength. 3. The results revealed very strong compartmentalization within the guild of pupal fly parasitoids, with four species attacking only Philornis spp. Both specificity indices indicated significant levels of specificity toward the genus Philornis for two of these species: Conura annulifera and Trichopria sp. novus. We also assessed the specificity of the two dominant Philornis species attacking 11 bird species and the preference of the two dominant parasitoid species for bird species. Although there was some significant preference for particular bird species by the Philornis spp., there was no indication that this drove specificity patterns by the parasitoids.
Description
Data set in excel format
License
CC0 1.0 Universal
Description
Data set in excel format
License
CC0 1.0 Universal
Date made available | Apr 27 2022 |
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Publisher | Data Repository for the University of Minnesota |
Date of data production | Jan 1 2013 - Jun 30 2018 |