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Optimizing the Sex Pheromone of Greater Wax Moth, Galleria mellonella (Lepidoptera: Pyralidae): Electrophysiological and Behavioural Analyses for Stereoisomers of 5,11-dimethylpentacosane

Azhar, Zainab (2016) BIOM01 20152
Degree Projects in Biology
Abstract
The greater wax moth, Galleria mellonella, is a serious pest of honey bees, Apis mellifera, damaging the quality of honey produced and creating a problem for bee industry. Mating behaviour in this species takes place with the help of a male-released pheromone tracked by females over long distances. Previously, the male pheromone was identified to be a blend of nonanal and undecanal but this aldehyde blend failed to elicit attraction over longer distances. A recent study discovered a new component for this pheromone blend (5,11-dimethylpentacosane), which along with aldehydes showed better attraction than aldehydes alone. In this study, electrophysiological and behavioural analysis were carried out with the G. mellonella females in order to... (More)
The greater wax moth, Galleria mellonella, is a serious pest of honey bees, Apis mellifera, damaging the quality of honey produced and creating a problem for bee industry. Mating behaviour in this species takes place with the help of a male-released pheromone tracked by females over long distances. Previously, the male pheromone was identified to be a blend of nonanal and undecanal but this aldehyde blend failed to elicit attraction over longer distances. A recent study discovered a new component for this pheromone blend (5,11-dimethylpentacosane), which along with aldehydes showed better attraction than aldehydes alone. In this study, electrophysiological and behavioural analysis were carried out with the G. mellonella females in order to find which of the four isomers of 5,11-dimethylpentacosane provides maximum response. In both electrophysiological and behavioural experiments, 5R,11R-dimethylpentacosane generally received significantly higher response than the rest of synthetic treatments. Still the level of attraction to 5R,11R-isomer was lower than that to male extract, indicating that the composition of the synthetic blend is suboptimal, or that additional pheromone components of G. mellonella are yet to be identified. Relatively stronger response of G. mellonella females to 5R,11R-dimethylpentacosane is a considerable step for the improvement of efficient attractant bait for longer distances. Further on, it can be incorporated with environmentally safe strategies to reduce damage to beehives caused by wax moths. (Less)
Popular Abstract
Optimizing Pheromone Blend of Greater Wax Moth

Honey bees are important pollinators for many crops worldwide and serve as helpful creatures in maintaining incredible biodiversity through our ecosystems. The wax moth is a serious pest of honey bees as they attack bee hives weakened by natural or artificial factors. As a result, honey bees are affected and particularly the honey produced. Using pesticides as a control leaves residues in honey. Instead, using synthetic pheromone to interrupt wax moth mating behaviour will result in a long lasting and environmentally safe control.

Pheromones are substances emitted by an individual and received by a second individual of the same species, inducing a specific reaction. In order to control... (More)
Optimizing Pheromone Blend of Greater Wax Moth

Honey bees are important pollinators for many crops worldwide and serve as helpful creatures in maintaining incredible biodiversity through our ecosystems. The wax moth is a serious pest of honey bees as they attack bee hives weakened by natural or artificial factors. As a result, honey bees are affected and particularly the honey produced. Using pesticides as a control leaves residues in honey. Instead, using synthetic pheromone to interrupt wax moth mating behaviour will result in a long lasting and environmentally safe control.

Pheromones are substances emitted by an individual and received by a second individual of the same species, inducing a specific reaction. In order to control wax moth population, optimal mimic of it’s natural pheromone is essential. Over the past years, researchers have found three main components of this male-produced pheromone, two aldehydes (nonanal, undecanal) and a hydrocarbon (5,11-dimethylpentacosane). These components were found to generate some response from female wax moths. The hydrocarbon has four isomers (SS,SR,RS,RR) and the aim of this project was to find which one of these four isomers, receive the strongest response from female moth.

The scope of this project included two main steps. In the first step, small amounts of each isomer were brought in contact with the antenna of female moths and their responses were recorded. In the next part, wax moth’s flight behaviour was observed towards particular stimuli prepared including extract of male wax moths and some blends of main pheromone components.

The most optimal stimulus

In the results of both main stages, RR-isomer was found to be the preferred one by female moths. All tested moths showed relatively more attraction for RR-isomer as compared to other isomers. However, the level of attraction to this isomer was still lower than male extract, indicating that probably additional pheromone components are yet to be identified.

Relatively stronger response to one of the isomers is a considerable step for efficient attraction of wax moths. Along with a proper distribution device, this improved blend should be able to keep control of the wax moth population. Thus the contribution of this project can definitely be incorporated with environmentally safe strategies to reduce damage caused by wax moths to bee hives.



Advisor: Glenn Svensson
Master´s Degree Project 30 credits in Biology * 2016
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Azhar, Zainab
supervisor
organization
course
BIOM01 20152
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8611784
date added to LUP
2016-02-10 11:10:56
date last changed
2016-02-10 11:10:56
@misc{8611784,
  abstract     = {The greater wax moth, Galleria mellonella, is a serious pest of honey bees, Apis mellifera, damaging the quality of honey produced and creating a problem for bee industry. Mating behaviour in this species takes place with the help of a male-released pheromone tracked by females over long distances. Previously, the male pheromone was identified to be a blend of nonanal and undecanal but this aldehyde blend failed to elicit attraction over longer distances. A recent study discovered a new component for this pheromone blend (5,11-dimethylpentacosane), which along with aldehydes showed better attraction than aldehydes alone. In this study, electrophysiological and behavioural analysis were carried out with the G. mellonella females in order to find which of the four isomers of 5,11-dimethylpentacosane provides maximum response. In both electrophysiological and behavioural experiments, 5R,11R-dimethylpentacosane generally received significantly higher response than the rest of synthetic treatments. Still the level of attraction to 5R,11R-isomer was lower than that to male extract, indicating that the composition of the synthetic blend is suboptimal, or that additional pheromone components of G. mellonella are yet to be identified. Relatively stronger response of G. mellonella females to 5R,11R-dimethylpentacosane is a considerable step for the improvement of efficient attractant bait for longer distances. Further on, it can be incorporated with environmentally safe strategies to reduce damage to beehives caused by wax moths.},
  author       = {Azhar, Zainab},
  language     = {eng},
  note         = {Student Paper},
  title        = {Optimizing the Sex Pheromone of Greater Wax Moth, Galleria mellonella (Lepidoptera: Pyralidae): Electrophysiological and Behavioural Analyses for Stereoisomers of 5,11-dimethylpentacosane},
  year         = {2016},
}