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Relatedness and competition between caterpillars of Maculinea alcon within host plants

Blom, Lærke Breum (2016) BIOK01 20152
Degree Projects in Biology
Popular Abstract
Competition between related caterpillars on host plant

The Alcon Blue is a butterfly with a parasitic lifecycle. The butterfly starts its life on the Marsh Gentian were the caterpillars feed on the seeds within the flower bud. Several females lay eggs on the flower, which could mean that related caterpillars could potentially compete for the resources within the flower bud as there is a limit to have much offspring it can support. After feeding and developing through three different sizes, leaving behind skin, fras and hard shelves, the caterpillars will eventually drop to the ground where it wait to be meet by a foraging worker ant of the genus Myrmica. The ant will think the caterpillar is lost ant brood and carry it back to the nest... (More)
Competition between related caterpillars on host plant

The Alcon Blue is a butterfly with a parasitic lifecycle. The butterfly starts its life on the Marsh Gentian were the caterpillars feed on the seeds within the flower bud. Several females lay eggs on the flower, which could mean that related caterpillars could potentially compete for the resources within the flower bud as there is a limit to have much offspring it can support. After feeding and developing through three different sizes, leaving behind skin, fras and hard shelves, the caterpillars will eventually drop to the ground where it wait to be meet by a foraging worker ant of the genus Myrmica. The ant will think the caterpillar is lost ant brood and carry it back to the nest where its feed by regurgitation as known from birds. Ironically as this butterfly is often referred to as the cuckoo of butterflies as it also use other species to reared its offspring.

Oviposition strategy
The oviposition strategy for the species have been the interest of many scientists and thus resulted in numerous studies and theories. Is the butterfly able to detect the present of the ants when choosing a place for deposition of eggs? Can it detect eggs already present on the plant? If, would it lead to fewer or higher amount of eggs? What would be the most optimal for the butterfly thinking about the survival of its offspring? Which of these two hosts has the biggest effect on the survival of the butterfly? What type of competition exist within the flower bud and in the ant nest? Are the competition between related caterpillars? The answer to the last question is yes, to some extent. I have investigated the degree of relatedness between caterpillars by analysing the genetic material from caterpillars emerging from different plants and dissected all the flower heads on the plants in order to find evidence from there development and competition. There was no apparent difference in the amount of head capsules and the amount of emerging caterpillars, which means no apparent evidence from competition within the flowers. Though there might be a negative relationship between the number of eggs laid on the flower bud and the number of caterpillars that emerge from the flower bud. Meaning that a higher amount of eggs laid on a flower bud would lead to fewer caterpillars emerging, making it a density dependent mortality. Contradicting model and theories proposed as explanation for
the ovipositon in insects.

Studies like this contributes to the understanding of a species basic ecology, which in turn can be used for improving management plans and ultimately the conservation of the species. In addition this species is known as an umbrella species, which mean that be conserving the species, many other species benefits as they also need these habitats in order to survive and persist in a world consisting of still fewer green areas.

Supervisor: David R. Nash and Bengt Hansson
Degree Project 15 credits 2015
Department of Biology, Lund University
University of Copenhagen (Less)
Please use this url to cite or link to this publication:
author
Blom, Lærke Breum
supervisor
organization
course
BIOK01 20152
year
type
M2 - Bachelor Degree
subject
language
English
id
8840928
date added to LUP
2016-03-10 14:02:55
date last changed
2016-03-10 14:02:55
@misc{8840928,
  author       = {Blom, Lærke Breum},
  language     = {eng},
  note         = {Student Paper},
  title        = {Relatedness and competition between caterpillars of Maculinea alcon within host plants},
  year         = {2016},
}