The role of competition in adaptive radiation: a field study on sequentially ovipositing host-specific seed predators - Archive ouverte HAL Access content directly
Journal Articles Journal of Animal Ecology Year : 2004

The role of competition in adaptive radiation: a field study on sequentially ovipositing host-specific seed predators

(1) , (1)
1
Laurence Després
  • Function : Author
  • PersonId : 838359
Mehdi Cherif

Abstract

1. We propose an alternative model to the host-shifting model of sympatric speciation in plant-insect systems. The role of competition in driving ecological adaptive radiation was evaluated in a seed predator exploiting a single host-plant species. Sympatric speciation may occur through disruptive selection on oviposition timing if this shift decreases competition among larvae feeding on seeds. 2. The globeflower fly Chiastocheta presents a unique case of adaptive radiation, with at least six sister species co-developing in fruits of Trollius europaeus. These species all feed on seeds, and differ in their oviposition timing, one species ovipositing in 1-day-old flowers (early species), while all the other species sequentially oviposit throughout the flower life span (late species). We evaluated the impact of conspecific and heterospecific larvae on larval installation success, and on larval fresh mass and area, for early and late species, in natural conditions. 3. None of the three larval traits measured was correlated with fruit size, and no fruit lost all seeds to predation, suggesting that seed availability was not a limiting factor for larval development. 4. Our results show strong intraspecific competition among early larvae for larval installation, and among late larvae for larval mass. By contrast, larval competition between species was weak. These results are consistent with the hypothesis that shifts in oviposition promoted rapid radiation in globeflower flies by lowering competition among larvae.
Not file

Dates and versions

hal-03699345 , version 1 (20-06-2022)

Identifiers

Cite

Laurence Després, Mehdi Cherif. The role of competition in adaptive radiation: a field study on sequentially ovipositing host-specific seed predators. Journal of Animal Ecology, 2004, 73 (1), pp.109-116. ⟨10.1111/j.1365-2656.2004.00785.x⟩. ⟨hal-03699345⟩

Collections

IRSTEA INRAE
20 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More