The document discusses research on the effects of gut bacteria on the development and fitness of the oriental fruit fly Bactrocera dorsalis. The research investigated supplementing diets of B. dorsalis with different bacterial isolates to see effects on development time, survival rates, and weight [1]. Results showed that diets supplemented with Enterococcus phoeniculicola and Citrobacter freundii reduced development time and increased survival rates and weight compared to controls [2]. A second study evaluated supplementing diets of sterile male B. dorsalis with E. phoeniculicola and C. freundii and found it improved their mating competitiveness and reduced female remating rates compared to controls [3].

1. 研 究 生：
CANDIDATE:
KANJANA KHAESO
学 号:
STUDENT NO.:
2013301060016
导 师:
SUPERVISOR:
牛长缨 教授
PROF. NIU CHANG YING
SYMBIOTIC BACTERIAAND THE FITNESS OF ORIENTAL FRUIT
FLY, BACTROCERA DORSALIS WITH REFERENCE TO THE
STERILE INSECT TECHNIQUE(SIT)
1

2. Global pest
Attacks ≥ 250 specie fruits
and vegetables
Bactrocera dorsalis (Diptera:Tepritidae)
Longan Peach Orange Rose apple Guava Mango

3. 3
First report
 Koshun, Taiwan 1912 (Hardy 1973)
Hainan Island 1934 (Xie 1937)
China mainland 1950 (Wang 1996)

4. Some current pest management strategies
4
Insecticide Control Biological control (D. Kraussi)
Sterile insect control Technique Traps
Used for years
Little success

5. WAY FORWARD
5
Sustainable
Efficient
Cost-effective
The strategy have been developed to take advantage
namely the sterile insect technique (SIT).
Sterile insect Technique
(SIT)

6. Mass rearing of male flies
Disadvantage
 Sterile male are weak
 Less compete with wild flies
Advantage
 Environmental friendly
 Large area control

7. IMPORTANCE OF SYMBIONTS
 Provide nutrition for their host.
 Provide insect defence and
survival in extreme conditions.
 Manipulate the reproductive
system of their host
7
Biotechnological applications of targeting microbial symbionts in insects.
Targeting these symbiotic interactions
can have broad applications in
• controlling populations of insect
pests,
• utilizing the symbionts for
industrially important processes
• increasing the survival of
beneficial insects

8. Introduction
 The efficacy of the SIT is determined by the quality of insects mass-reared in
production facilities
 The need to develop cost effective strategies of insect maintenance in the lab
 The hypothesis is that the bacteria that form the major microbial populations
contributing to the fitness of the fly host.
 To investigate the effects of supplementing diets with different bacteria isolates
on insect productivity, weight, as well as development duration of pre-adult
stage.
Assessing the effect of gut bacteria manipulation on
the development of the B. dorsalis
8

9. 9
Phylogenetic tree showing the relationship among individual bacterial 16S rRNA gene isolates from
Bactrocera dorsalis genetic sexing strain. Genebank accession numbers are followed by bacteria species.
Bacterial isolated used for feeding experiment

10. Development time
Larva
Pupa
Adult
Size
Survival rate
Material and methods Compare phenotype of hosts with and
without symbionts in larvae fed
(development, survival, weight)
Egg
Bacteria isolate
+
Diet

11. 11
The bacteria growth rate using for research are Enterococcus gallinarum (E-g), Klebsiella pneumoniae (K-p), Enterococcus
phoeniculicola (E-p), Lactococcus garvieae (L-g), Lysinibacillus macroides (Ly-m), Morganella morganii (Mo-m), Providencia
rettgeri (P-r), Myroides odoratimimus (M-o), Klebsiella veriicola (K-m), Enterococcus avium (E-a), Proteus vulgaris (Pr-v),
Enterococcus termitis (E-t), Proteus mirabilis (Pr-m), Vagococcus fluvialis (V-f), Providencia rustigianii (P-ru), Lactococcus lactis
(L-l), Microbacterium sp. Green (Mi), Citrobacter freundii (C-f).
Results

12. 12
Results
For treatment abbreviation were Control= CK, E. gallinarum= Eg, E. phoeniculicola = Ep, E. avium= Ea, E. termitis= Et, L. lactis =
Ll, L. garvieae =Lg, V. fluvialis =Vf, L. macroides =Lym, K. pneumoniae =Kp, M. morganii =Mm, C. freundii =Cf, M. odoratimimus
=Myo and Microbacterium sp.= Mic.
The effects of bacterial supplemented larval diets on larva and pupa
developmental duration.

13. 13
Results The effects of bacterial supplemented larval diets
on total developmental duration.
For treatment abbreviation were Control= CK, E. gallinarum= Eg, E. phoeniculicola = Ep, E. avium= Ea, E. termitis= Et, L. lactis =
Ll, L. garvieae =Lg, V. fluvialis =Vf, L. macroides =Lym, K. pneumoniae =Kp, M. morganii =Mm, C. freundii =Cf, M. odoratimimus
=Myo and Microbacterium sp.= Mic.

14. The effects of bacterial supplemented larval diets on survival rate at different
developmental stages.
Genus Species Larval recovery (%) Pupa recovery (%) Total survival (%)
Control CK 50.3 ± 2.4 87.5 ± 1.1 44.0 ± 1.5
Enterococcus
E. gallinarum Eg 48.3 ± 5.8 91.1 ± 2.4 44.0 ± 5.1
E. phoeniculicola Ep 57.0 ± 0.6 91.2 ± 1.8 52.0 ± 1.2
E. avium Ea 53.7 ± 2.7 94.6 ± 1.8 50.7 ± 2.2
E. termitis Et 43.3 ± 3.8 90.3 ± 6.3 39.0 ± 4.0
Lactococcus
L. lactis Ll 47.7 ± 2.6 44.2 ± 1.9*** 21.0 ± 0.6***
L. garvieae Lg 52.0 ± 1.7 81.8 ± 4.5 42.7 ± 3.8
Vagococcus V. fluvialis Vf 41.7 ± 8.7 75.5 ± 9.1 33.0 ± 9.9
Lysinibacillus L. macroides Lym 53.7 ± 3.8 89.9 ± 3.6 48.0 ± 1.5
Klebsiella K. pneumoniae Kp 52.0 ± 2.6 69.7 ± 10.3* 36.7 ± 7.2
Morganella M. morganii Mm 47.7 ± 1.2 76.0 ± 6.5 36.3 ± 3.8
Citrobacter C. freundii Cf 49.7 ± 4.2 93.8 ± 2.6 46.7 ± 4.4
Myroides M. odoratimimus Myo 51.3 ± 2.0 88.5 ± 3.4 45.3 ± 0.9
Microbacterium Microbacterium sp. Mic 54.0 ± 2.1 64.5 ± 4.7** 35.0 ± 3.8
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Results

15. Development time Survival rate
Larvae Pupae Larvae Pupae
weight
Correlation (r) -0.725** 0.586** 0.617** 0.151
Sig. (p) 0.001 0.008 0.005 0.538
** Correlation is significant at the 0.01 level (2-tailed).
The correlation between wet weight, development time and survival with the Correlation (r) and the P-value.
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Results The correlation between wet weight and development duration

16. 16
Growth rate
Reduced growth rate
Increase growth rate
Adult
size
(mg)
Shorter growth period
Longer growth period
E. p
C. f C. k
L. l
Adult
size
(mg)
Shorter growth period
Results

17. Introduction
 The disruption leads to the reduced mating competitiveness of sterile males. Need to
understand the correlation between flies and associated symbiont.
 The efficacy of the SIT is determined by the quality of insects mass-reared in
production facilities, irradiated and released in the field. The need to promote health
and fitness of insect maintenance in the lab.
 To evaluate the effects of the probiotics on the mating competitiveness of the sterile
males, the probiotic bacteria were inoculated to adult diet (probiotic group) and the
diet without bacteria referred to control group.
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Enriched bacteria diets to boost the SIT application
in sterile male B. dorsalis

18. Capture mating
couples
Mass rearing of flies
+
• Newly Adult male (irradiated) were feed with
1. Normal diet without Bcateria (CK)
2. E. phoeniculicola (Ep)
3. C. freundii (Cf)
4. C. freundii + E. phoeniculicola (Cf +Ep)
 Male mating success
 Weight
 Biochemical analysis
Release 20 treated and
20 un-treated males 15-30 minutes
Male flies were mark 24
hrs before mating test
Material and methods
M:F= 2:1
•Female(Mated) x Male (Virgin)
Female remating
Test

19. 19
Mating competitiveness test
All matings by
sugar fed male
Equal
competitiveness of
both males
All matings by
bacteria fed males
The Female remating
Results
Relative sterility index value resulting from mating success of bacteria fed and sugar fed male. The bacteria enriched
diet including C. freundii (Cf), a mixture of C. freundii (Cf) + E. phoeniculicola (Ep) and E. phoeniculicola (Ep).

20. 20
Results The comparative of biochemical content and weight of sterile male fed
with symbiotic bacteria and control flies.

21.  The enriching the sterile male diet with E. phoeniculicola significantly improved
sterile male mating success (P< 0.0001).
 Moreover, re-mating of females first mated to E. phoeniculicola or C. freundii
enriched sterile male diet were significantly lower.
 E. phoeniculicola and C. freundii group showed significantly enhanced the glucose
content of sterile male.
 The data demonstrate that beneficial bacterial species supplement to the diets can
improve sterile male dietary and mating performance.
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Summary

22. Thank you for your attention
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