Drosophila suzukii Studies

Marissa Diorio

Dr. Fingerut

Elizabeth KrohnThomas SmithStephanie Tittaferrante

Dr. McRobert

Our ObjectivesDr. 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

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.htmlhttp://labs.russell.wisc.edu/swd/

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

The threat● Hundreds of offspring

http://whatcom.wsu.edu/ipm/manual/black/spotted_wing.html http://entnemdept.ufl.edu/creatures/fruit/flies/drosophila_suzukii.html

● Rapid life cycle

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?

Overwintering● Winter knocks down the population● How are they repopulating?

○ Migration○ A few survive in nature○ A few survive in structures

Chill Study● Room temperature vs. Chilled

○ measure of adult survivorship○ measure of time to pupation○ measure of time to eclosure

● Stunted reproduction

Further research● Construction of a mesocosm ● Observation of reproductive

physiology as the weather changeso if surviving, where and in what life stage?

● Hope to find evidence to explain disappearance

Technique Notes● Population boxes

● Traps

The Blueberry Study● Blueberries in D. suzukii

reproduction studieso 4 different conditions (20

offspring producing flies each)1. Blueberry / Blueberry2. Blueberry / No blueberry3. No blueberry / No

blueberry4. No Blueberry / Blueberry

The Blueberry Study - Step 1● Collection

o Within 6 hourso Juveniles

Pale, large● Housing

o Males - 1/vial Media + yeast

o Females - 1/vial Media + yeast Media + yeast + blueberry

The Blueberry Study - Step 2

● Experimental Assayso Testing 3-5 days oldo Transfer 1 male and 1

female to a vial No blueberry

o Observe flies - 60 min Copulation latency Copulation duration

D. suzukii courtship

The Blueberry Study - Step 3● After the experimental

assay…o Transfer mated female

Vial = Media + yeast Vial = Media + yeast +

blueberry

The Blueberry Study - Step 4● 7 days later…sucrose extraction

o Count offspring:1. Eggs2. Larvae3. Pupal cases

Copulation Frequency

Copulation Latency and Duration

Offspring Production

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

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

Individual Fly Study● Work with individuals, not mass

quantities● Specific Equipment:

○ Dissecting Scope and Light○ CO2 Pad and Funnel○ Mouth Aspirator (Suck Tube)○ Paintbrushes

Conclusions: Why These Studies Matter

● Economic losses:o Yield losseso Increased laboro Increased chemical input costso Loss of foreign markets

● Loss of 20% of blueberry crops - $56.7 million - CA, OR, WA

● Current management - adult flies

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