biosecurity built on science
Understanding the microbiome of Queensland fruit fly to improve sterile insect technique
1. Plant Biosecurity Cooperative Research Centre (PBCRC), Australia
2. Elizabeth Macarthur Agricultural Institute (EMAI), NSW Department of Primary Industries
3. Hawkesbury Institute for the Environment (HIE), Western Sydney University
Plant Biosecurity Cooperative Research Centre
D Woruba1,2,3, O Reynolds2, M Riegler3, J Morrow3 & T Chapman1,2
biosecurity built on science
Queensland fruit fly (Qfly), Bactrocera tryoni Australia’s most significant
horticultural insect pest threatening crops valued at $640 million
Damages fruits and vegetables and affects trade
Broad-spectrum chemicals are being phased out
Current management includes monitoring, targeted chemical application, cultural practices and Sterile Insect technique (SIT)
biosecurity built on science
Sterile Insect Technique
SIT is “a method of pest control using area-wide inundative releases of sterile insects to reduce reproduction in a field population of the same species” FAO, 2014 (Insect birth control)
The success of SIT depends on sterile males mating with wild females
Mass rearing and irradiation lead to reduced fitness and performance of sterile males
biosecurity built on science
Probiotics
Greek “pro” + “bios” = "for life.”
“Live microorganisms which when administered in adequate amounts confer a health benefit on the host” FAO & WHO, 2006.
biosecurity built on science
Probiotics
Human products
Metchnikoff 1907
Animal products
Beneficial bacteria
biosecurity built on science
Beneficial bacteria in Insects
Beneficial bacteria in insects have been well documented- E.g. Obligate endosymbiosis of aphids and the Buchnera
bacteria- E.g. Gut bacteria linked to evolution of herbivory in ants
Tephritid fruit flies gut bacteria studied since early 1900s
biosecurity built on science
Aim
Characterization of complete gut microbiome of Qfly- Reared (lab) and wild Qfly populations- Ecological distribution (location & host)
Formulation of probiotic supplements to improve Qfly SIT
biosecurity built on science
Literature Review
Woruba et al (review manuscript) submitted
Roles of bacteria in tephritids:
- Protein metabolism
- Carbohydrate metabolism
- Longevity
- Attraction and communication
- Mating and reproductive performance
biosecurity built on science
-80°C StorageGut isolation
Fitness testsProbiotic
formulations Culture bacteria
Field Collection Molecular ID
The “sexy back” plan
Effective “sexy” sterile male Qfly
biosecurity built on science
Reared Qfly Microbiome Pupae;
- EMAI (lucerne as diet bulking agent) Sterile Fertile
- HIE (carrot as diet bulking agent) Fertile
Adults- Tenerals (≈12 hrs post-eclosion) - Mature (14 days post-eclosion).
yeast and sugar (3:1) sugar only
Adult rearing
biosecurity built on science
♂ ♀ ♂ ♀ ♂ ♀ YS♂ YS♀ S♂ S♀ S♂ S♀ YS♂ YS♀ YS♂ YS♀ S♂ S♀0
5000
10000
15000
20000
25000
30000
35000
40000
45000 Average count of 16s rDNA reads
Reared Qfly Microbiome: Results
TENERALS
MATURE
EMAI EMAIHIE HIE
Sterile Fertile
CO
UN
TS
biosecurity built on science
♂ ♀ ♂ ♀ ♂ ♀
YS♂
YS♀ S♂ S♀ S♂ S♀ YS♂
YS♀
YS♂
YS♀ S♂ S♀
Fertile
Fertile
Ster-ile
Ster-ile
Fertile
Fertile
Fertile
Fertile
Fertile
Fertile
Ster-ile
Ster-ile
Ster-ile
Ster-ile
Fertile
Fertile
Fertile
Fertile
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
EnterobacteriaceaeAcetobacteraceaeLactobacillaceaeXanthomonadaceaeFlavobacteriaceaeLegionellaceaeMoraxellaceaeSphingomonadaceaeHyphomicrobiaceaePseudomonadaceaeOthers
EMAI EMAI
MATURE
HIE
Reared Qfly Microbiome: ResultsTENERALS
Bacterial diversity of mass-reared teneral and mature Bactrocera tryoni
HIE
biosecurity built on science
Reared Qfly Microbiome: Conclusion
Microbiome of mature Qfly is dominated by Enterobacteriaceae
Teneral flies have low bacterial density
Bacterial population increases with fly maturation (either through cell division or uptake from environment)
Ideal time point of supply of probiotic candidates is in teneral stage
biosecurity built on science
Source: Dominiak & Daniels 2012
MareebaAtherton
Kuranda
RedlandsMt. Coot-tha
Sunshine Coast
Central Coast
HawkesburyCamden
Wild Qfly Microbiome
Qfly Sampling Wild
Native and Commercial Habitats
Host fruits Locations
Lab reared Sterile and fertile
biosecurity built on science
Use of 5 selective media for culturing bacterial isolates
Identification of isolates using molecular and bichemical tools
Candidates identification and culturing
Culture bacteria
biosecurity built on science
Identification of potential probiotic candidates and develop formulations
Test for: Improved stress resistance & survival Enhanced sexual mating performance (Flyagra)
Fitness tests
Fitness testsProbiotic formulations
biosecurity built on science
Thank you
The gutsy search for a sexy solution
Top Related