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Sunrise. Flight at oviposition site, Aug 21-22. 1. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10 ... Sunrise. Flight at oviposition site. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 0. 5. 10. 15. 20. 25. 30. 35 ...
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1. Studies in the Cambridge rainforest
Paul Reiter CDC West Nile Project Harvard School of Public Health
2. A collaborative study
Harvard School of Public Health Massachusetts State Laboratory Institute Cambridge Public Health Department East Middlesex Mosquito Control Project Central Massachusetts Mosquito Control Project CDC Division of Vector-Borne Infectious Diseases, and:
3. Egg-rafts in natural sites
4. Cx.restuans egg-rafts, Memphis, 1981
5. Hay infusion
6. On the road
7. The trap is laid
8. Convenient collecting vessel
9. Species identification in the 1st instar
egg-breaker
10. Egg rafts, Memphis,1982
11. Memphis, 1983, Cx. restuans eggs
12. Gravid mosquitoes, 1983
13. 1983, Cx. restuans, gravid females
What is the impact of ULV treatments on Culex pipiens and Cx. restuans?15. Bioassay Cages
16. Memphis, Resmethrin, 0.0062 lb/acre
1 2 3 4 5 6 7 8 9 10 11 12 0 10 20 30 40 50 60 egg-rafts per site day of trial
17. Memphis, mean % change, 4 trials
18. Summary of observations, Memphis
Springtime restuans and enzootic transmission coincide Dramatic early summer disappearance of restuans Dramatic fall reappearance of restuans Principal Cx. pipiens activity after restuans dormancy ULV resmethrin effective against Culex species
0.00 5 10 15 20 25 30 35 40 45 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 1-Jan egg-rafts per pan date19. Egg-raft collections, Boston, 2001
20. Culex larval infestation rates
Cambridge Yards: 27% positive (n = 30) Jamaica Plain Catch basins: 38% positive (n = 100)
21. Burlington, resmethrin, 0.001 lb/acre
egg-rafts per site
22. Framingham, Resmethrin, 0.00175 lb/acre
23. Tewksbury, Resmethrin, 0.007 lb/acre
4-Sep 5-Sep 6-Sep 7-Sep 8-Sep 9-Sep 10-Sep 11-Sep 12-Sep 13-Sep 0 2 4 6 8 10 12 14 egg-rafts per site date
Why was ULV resmethrin effective against Culex spp in Memphis … but not in Massachusetts … ?25. Possible reasons?
Application rate? Street plan? Vegetation? Weather variables? Mosquitoes behavior?
26. Egg-raft collections, after August 1
n n n n n l l l l l 20-Aug 27-Aug 3-Sep 10-Sep 17-Sep 0 5 10 15 20 egg rafts per site week27. Egg-raft collections in fall
p = 0.94
28. Bird-baited trap
29. Urban Culex are canopy feeders?
Ground Canopy 840
30. Decline of Culex adults in autumn
September October
31. Parous rate of blood-feeding Culex
These mosquitoes ecloded before August 10th? Mosq. Parous % 7 77.8 10 100.0 22 95.7 11 100.0 4 100.0 4 100.0 4 100.0 6 100.0 16 88.9 1 100.0 9 100.0 13 100.0 6 100.0 9 6 100.0 124 119 97.3 Sep 20
32. Questing at caged starling, Sept 10-11
33. Questing at caged starling, Sept 11-12
34. Questing at caged starling, Sept 12-13
35. Flight at oviposition site, Aug 21-22
36. Flight at oviposition site
Mean of 4 nights data
37. Overwintering
38. Survival in overwintering Culex
Cold winter El Niño winter
39. Conclusions (Boston): background data
Cx restuans and Cx pipiens are abundant Source is not clear Catch basins may not be significant as source
40. Blood feeding
Cx. restuans and pipiens feed in tree canopy Questing occurs throughout the night
41. Oviposition
Flight over sites mainly in early night Oviposition mainly late in night
42. After early August …
Pre-diapause adults feed and oviposit Diapausing adults do not feed Survival rate of pre-diapause adults is high Adulticides: major impact on transmission? Survival of overwintering adults is high
43. Acknowledgements
Duane Gubler Andy Spielman Richard Pollack Tony Kiczewski Chris Mores Sam Telford Mike Reddy TJ Lepore Sejal Shah Matthew Garland Brian Spencer Patrick Barton Nina Kishore Henry Goldfarb David Goldfarb Ralph Timperi Barbara Werner Sam Lipson David Henley Tim Deschamps Gary Alpert James Willcox Larry Acosta Paul Meyvaert Curtis Brown & Diane Allen About 120 householders