Award Date

May 2018

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Life Sciences

First Committee Member

Daniel Thompson

Second Committee Member

Allen Gibbs

Third Committee Member

Javier Rodriguez

Fourth Committee Member

Ronald Gary

Number of Pages

64

Abstract

Butterflies are a diverse and essential group of pollinators whose abundance is predominantly determined by growth and survival of their larvae. In the family Lycaenidae, many species participate in a larval-ant mutualism where ants feed on nutrient-rich nectar produced by larvae and, in turn, protect those larvae from predators. Emerging evidence indicates larval scent in the form of cuticular hydrocarbons (CHCs), not nectar production, drives this interaction. This study takes two approaches to investigate CHCs as the driver behind the larval-ant mutualism in three butterfly species native to southern Nevada: Euphilotes bernardino martini (Martin’s blue), Brephidium exilis (western pygmy blue), and Euphilotes ancilla (Rocky Mountain dotted blue). First, behavioral assays are conducted to investigate larval-ant interactions in early and late larval instars both with live larvae and beads coated in larval extract. Second, the general composition of hydrocarbons found on the larval cuticles of these mutualist species is identified along with those from four species of attendant ants (Forelius pruinosus, Camponotus spp, Crematogaster mormonum, and Linepithema humile) to determine how varying CHC composition may be implicated in initiating and maintaining this important mutualism. In addition, this study addresses the novel hypothesis that early instar larvae produce a simple CHC suite to avoid ant aggression and then, in late instars, switch to producing a complex CHC suite that encourages ant interaction. This study finds partial support for CHC overlap in mutualist larvae and ants but does not find support for a developmental shift in CHC production.

Keywords

inter-species communication; mutualism breakdown; Polyommatinae

Disciplines

Environmental Sciences | Terrestrial and Aquatic Ecology

Language

English


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