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Raspberry ketone as a promising pre-release supplement for the Sterile Insect Technique (SIT) of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)

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posted on 28.03.2022, 22:57 authored by Humayra Akter
Queensland fruit fly, Bactrocera tryoni Froggatt (Qfly) (Tephritidae), Australia’s most economically damaging fruit fly, infests more than 100 hosts including many commercially important crops. Control of this pest is based on insecticides, bait sprays, male annihilation technique (MAT), and in some regions sterile insect technique (SIT). SIT can be a highly effective control method, and is used around the world to control some of the worst fruit fly pests, but high field mortality of the sterile flies can constrain the success of Qfly SIT. Improved quality of released males and acceleration of sexual maturation can help to overcome this problem. In this thesis I investigated potential beneficial effects of supplementing immature Qflies with raspberry ketone (RK), a metabolic enhancer. RK was mixed with the diet for 48 hours, a duration consistent with standard pre-release holding periods.When RK was provided together with yeast hydrolysate (YH), RK-fed males exhibited accelerated development of reproductive organs and increased mating propensity when 6 - 9 days of age. Positive effects of RK were not evident in males that were fed only sugar, and no positive effects of RK were evident for female development regardless of diet. As sex pheromone plays important role in calling and courtship, I investigated effects of RK on pheromone production. RK-fed males produced significantly more pheromone, and RK was detected in the pheromone blend. Increased pheromone production and presence of RK in pheromone blend may be an important factor in elevated mating propensity of RK-fed male Qflies. While mating is an important step in SIT, female remating behaviour is also important as females that mate with a released male and then a wild male will likely retain fertility. Females that mated with RK-fed males, including during the period of accelerated development, exhibited remating tendency that was similar to females mated by control males. That is, not only does RK feeding increase development rate and early mating propensity of male Qflies, the early matings of RK-fed males are of undiminished effectiveness. SIT could potentially be greatly enhanced if combined with MAT, and my studies have identified a potential new way to enable this. In some other Bactrocera, mature males that feed on lures are then unresponsive to lures for substantial periods, and so would not be attracted to MAT devices. However, combination of SIT and MAT has been considered unsuitable for Qfly owing to long adult maturation period and high mortality in attempts to hold the flies to maturity before release. I found that RK-fed males exhibit a persistent reduction in responsiveness to cuelure traps, opening the possibility of simultaneous MAT and SIT application in Qfly control programmes. In addition to considering potential beneficial effects of pre-release RK supplements it is also important to consider potential drawbacks for survival. When a source of protein + sugar was available throughout life, RK supplements did not affect survival. However, RK supplements did increase susceptibility to desiccation and food deprivation in the period immediately following pre-release treatment. This thesis comprises the first series of studies to consider RK as a potential pre-release treatment for SIT in the context of a standard 2 - 3 day pre-release holding period. The substantial beneficial effects of RK supplements on development, mating, and lure response support a strong case for further investigation and consideration for trial deployment on operational SIT programs.

History

Table of Contents

Chapter One: General introduction -- Chapter Two: Raspberry ketone supplement promotes early sexual maturation in male Queensland fruit fly, Bactrocera tryoni (Diptera: Tephritidae) -- Chapter Three: Raspberry ketone supplement accelerates reproductive organ development of Queensland fruit fly, Bactrocera tryoni (Froggatt) -- Chapter Four: Sexual inhibition of female Queensland fruit fly Bactrocera tryoni (Froggatt) mated by young raspberry ketone supplemented males -- Chapter Five: Do raspberry ketone supplements provided to immature Queensland fruit fly Bactrocera tryoni (Froggatt) change sex pheromone quantity or composition? -- Chapter Six: Raspberry ketone feeding affects the tolerance of Queensland fruit fly Bactrocera tryoni (Froggatt) to nutritional and desiccation stress -- Chapter Seven: Suppression of cuelure attraction in male Queensland fruit fly Bactrocera tryoni (Froggatt) provided raspberry ketone supplements as immature adults -- Chapter Eight: General discussion.

Notes

Thesis by publication. Bibliography: pages 15-29, 32-33, 68-75, 94-102, 131-139, 167-176, 192-197 and 207-217

Awarding Institution

Macquarie University

Degree Type

Thesis PhD

Degree

PhD, Macquarie University, Faculty of Science and Engineering, Department of Biological Sciences

Department, Centre or School

Department of Biological Sciences

Year of Award

2017

Principal Supervisor

Phillip W. Taylor

Additional Supervisor 1

Ken Cheng

Additional Supervisor 2

Polychronis Rempoulakis

Rights

Copyright Humayra Akter 2018. Copyright disclaimer: http://mq.edu.au/library/copyright

Language

English

Extent

1 online resource (v, 218 pages)

Former Identifiers

mq:70488 http://hdl.handle.net/1959.14/1264753