1. Identification, Breeding Sites and Management
Small Flies
Andy Maganga
Identification, Breeding Sites and Management

2. Objective
By the end of the session, participants will- Have a better understanding of important biological features of common species of small flies, In order to- Develop better small fly management programs for their clients through identification of breeding sites, improved communication and more targeted control methods.

3. Significance of Small Flies
Are they a real or perceived threat to food safety?
Health Department Involvement and client auditors?
Nuisance status?
Defacing fixtures
Cost of inspection(s) and control programs

4. The main culprits Fruit/vinegar Fly (1) (2) Fungus gnat (4)
Dark-eyed Fruit Fly
(3)
Moth (Drain) Fly

5. Comparative Biological Features of Key Species
# of Eggs
# of Days
Egg to Adult
Adult Longevity
(Weeks)
Comments
 500
8 - 10
Newly-emerged adults attracted to light.
High reproductive rate
7-28 2
Attracted to Light
Egg & Larvae in slime
1.6 Km wind travel
Up to 300 17 10
Feed on soil fungi e.g. overwatered soil
Source may be indoor/outdoor plants

6. Distinguishing Phorid from Dark Red-eyed Fruit Flies
Drosophilidae
Phoridae

7. Biologicial features of Phorid flies
3.5 mm in length
Female lay egg in her life time (9-12 eggs/day)
Egg to Adult in 21 – 28 days
Breed in decaying organic matter of plant or animal origin (coffin fly)
Basically, they breed in material very similar to dark-eyed FF.
More problematic in sewage infested soil and leaking drains.
Check using a masking tape over drains or floor cracks.

8. Spotted-wing Drosophila (SWD) Why is it different from common vinegar fly?
D. suzukii introduced to California in 2008.
First identified in BC in 2009.
SWD females inject eggs in ripe fruit just before harvest.
Strawberries, Blackberries, grapes, cherry, peach,Cherry tomatoes
384 egg per female, Egg to Adult in days at 250C. Adults live 105 d at 100C
Implications for Urban pest control?

9. Seasonal Trends of Small Flies

10. Seasonal Trends of SWD

11. Differences in Breeding Habits
Fruit flies prefer comparatively the least decomposed material (rotting fruit, fruit peels, discarded fruit, compost bins, recycling bins etc.)
Dark-eyed fruit flies and Phorid flies prefer moderately decomposed material
Moth (drain) flies and fungus gnats prefer more decomposed (darker) organic material. However, fungus gnats require soil.

12. Why is it important to identify breeding sites with certainty?
The 20:80 rule
Control is easier once breeding sites have been identified.
Is it possible to achieve control without identifying key breeding sites?
Your Credibility

13. Dark-eyed Fruit Fly Breeding Sites Are they really breeding in drains?

14. Small Fly Breeding Sites Is it a sanitation or Structural Issue?

15. Small Fly Breeding Sites Is it a sanitation or Structural Issue?

16. Small Fly Breeding Sites Is it a sanitation or Structural Issue?

17. Small Fly Breeding Sites Is it a sanitation or Structural Issue?

18. Small Fly Breeding Sites Is it a sanitation or Structural Issue?

19. Typical Small Fly Breeding Sites Is this now purely a sanitation issue?

20. Small Fly Breeding Sites Sanitation or Structural Issue?

21. Small Fly Breeding Sites Sanitation or Structural Issue?

22. Small Fly Breeding Sites Which type of small fly is breeding here?

23. Typical Small Fly Breeding Sites Structural or Sanitation Issue?

24. Typical Small Fly Breeding Sites Structural or Sanitation?

25. Exterior breeding sites For which flies are they most significant?

26. Now that we have identified the species and breeding site, what are the next IPM step?
(5 Basic Steps; Identification, Inspection, Sanitation, Mechanical Control/Exclusion and Insecticide)
Communication
Monitor/Follow-up
Planning to prevention recurrence

27. Effective communication
Is it a sanitation issue or a structural issue?
Show and Tell
Documentation- for as long as the problem exists

28. Monitoring Tools

29. Monitoring for Key Species
Jar type traps using vinegar as bait are available. Numerical monitoring is challenging. Fly lights and sticky-type traps temporarily help.
Jar traps appear to be most effective but baits are limiting. Fly lights?
Easy to monitor with fly lights?
Sticky traps and fly lights are effective for monitoring.

30. Dichlorvos Strips How effective are they?
Domestic label, hence potential use by clients
Why is this one unlikely to work?

31. Use of Dichorvos Strips for Fly Control What does the product label allow?

32. Control/Management of Key Species
Removal/drying out of breeding material
ULV in severe situations
Treatment is rarely necessary
Pyrethroid aerosol, and Bti are labelled

33. Small Fly Management
Structural modification and sanitation are the most important part of sustainable small fly management.
Temporary relief can be achieved using adulticides chiefly ULV and residual treatment (swabbing) of landing sites.
Exterior treatment e.g. garbage bins can be useful.
Trapping alone (Light traps, Sticky traps etc) has limited success.
Bioremediation- preventative/corrective?

34. Questions?