1. Drosophila suzukii Studies
Marissa Diorio
Dr. Fingerut
Elizabeth Krohn
Thomas Smith
Stephanie Tittaferrante
Dr. McRobert

2. Our Objectives
Dr. McRobert’s Lab:
● Blueberry Fecundity Study
○ In Progress
● Remating Study
○ Starting Soon
● Hybridization Study with
D. biarmipes
Dr. Fingerut’s Lab:
● Overwintering Study
○ In Progress
○ Gauging lower lethal temperature
○ Construction of a mesocosm

3. Invasive Species
● Southeast Asia -> global trade -> Hawaii, California, USA, Canada,
Europe
● Climate prefer warm, temperate climate, but adaptable and resilient
http://ncsmallfruitsipm.blogspot.com/2013/02/spotted-wing-drosophila-confirmed-from.html
http://labs.russell.wisc.edu/swd/

4. The threat
http://entnemdept.ufl.edu/creatures/fruit/flies/drosophila_suzukii.htm
http://www.enetpress.com/drosophila/swd_index.html
http://www.virginiafruit.ento.vt.edu/SWD.html
http://entnemdept.ufl.edu/creatures/fruit/flies/drosophila_suzukii.htm

5. The threat
● Hundreds of offspring
http://whatcom.wsu.edu/ipm/manual/black/spotted_wing.htmlhttp://entnemdept.ufl.edu/creatures/fruit/flies/drosophila_suzukii.html
● Rapid life cycle

6. Suzukii’s late appearance
● Seem to disappear over winter and then re-
emerge in late summer
● Other species re-emerge in April
● What causes this disappearance?
o How can we utilize it?

7. Overwintering
● Winter knocks down the population
● How are they repopulating?
○ Migration
○ A few survive in nature
○ A few survive in structures

8. Chill Study
● Room temperature vs. Chilled
○ measure of adult survivorship
○ measure of time to pupation
○ measure of time to eclosure
● Stunted reproduction

9. Further research
● Construction of a mesocosm
● Observation of reproductive physiology as
the weather changes
o if surviving, where and in what life stage?
● Hope to find evidence to explain
disappearance

10. Technique Notes
● Population boxes
● Traps

11. The Blueberry Study
● Blueberries in D. suzukii
reproduction studies
o 4 different conditions (20
offspring producing flies each)
1. Blueberry / Blueberry
2. Blueberry / No blueberry
3. No blueberry / No blueberry
4. No Blueberry / Blueberry

12. The Blueberry Study - Step 1
● Collection
o Within 6 hours
o Juveniles
 Pale, large
● Housing
o Males - 1/vial
 Media + yeast
o Females - 1/vial
 Media + yeast
 Media + yeast + blueberry

13. The Blueberry Study - Step 2
● Experimental Assays
o Testing 3-5 days old
o Transfer 1 male and 1
female to a vial
 No blueberry
o Observe flies - 60 min
 Copulation latency
 Copulation duration

14. D. suzukii courtship

15. The Blueberry Study - Step 3
● After the experimental assay…
o Transfer mated female
 Vial = Media + yeast
 Vial = Media + yeast + blueberry

16. The Blueberry Study - Step 4
● 7 days later…sucrose extraction
o Count offspring:
1. Eggs
2. Larvae
3. Pupal cases

17. Copulation Frequency

18. Copulation Latency and Duration

19. Offspring Production

20. Technique Notes for D. Suzukii
● Paper towel & Moisture
○ Pupal case growth
● Blueberry/Yeast Food
○ True fruit fly
● Contamination Hazards
○ Bottles vs. Vials
○ Cotton Balls vs. Foam Stoppers

21. Cotton Ball Contamination Pictures
Stage One:
Growth of pupal
cases on cotton ball
Stage Two:
Pupal cases expand
and cause more gaps
Stage Three:
Flies hatch and
cause even more
space in cotton ball
Stage Four:
Flies find enough
space to escape
and/or enter vial

22. Individual Fly Study
● Work with individuals, not mass quantities
● Specific Equipment:
○ Dissecting Scope and Light
○ CO2 Pad and Funnel
○ Mouth Aspirator (Suck Tube)
○ Paintbrushes

23. Conclusions: Why These Studies Matter
● Economic losses:
o Yield losses
o Increased labor
o Increased chemical input costs
o Loss of foreign markets
● Loss of 20% of blueberry crops - $56.7
million - CA, OR, WA
● Current management - adult flies

24. Thank you Sponsors
● Saint Joseph’s Summer Scholars Program
● Dr. Scott McRobert
● Dr. Jonathan Fingerut
● McNulty Fellows Program
● SJU Biology Department
● Also, a thank you to students who previously
worked on this project
○ Kristina Orbe ‘14
○ Leigh Anne Tiffany ‘15