biology, ecology, and feeding behavior of mosquitoes in ... · 3/9/2020 · mosquito life cycle 4...
TRANSCRIPT
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John Shepard
Department of Environmental Sciences
Center for Vector Biology & Zoonotic Diseases
The Connecticut Agricultural Experiment Station
New Haven, CT
Biology, Ecology, and Feeding Behavior of
Mosquitoes in Connecticut
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• True flies (Order Diptera)
• Family Culicidae
• One pair of wings
• Forward projecting mouthparts = Proboscis
• Wings with scales & fringe hairs
• Over 3,500 species worldwide
• Over 150 species in US
• Why Identify?
– Evaluate Public Health Risks
– Implement Control Measures
Mosquitoes
Tom Murray, Bugguide.net
Tracy, bugguide.net
Tom Murray, bugguide.net
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Not Mosquitoes
Black Fly (Simulidae) No See Um (Ceratopogonidae) NEED BLOOD
DON’T TRASMIT
EEE
WNV
JC
J. Rosenfeld, BugGuide.net
Chironomid Midge (Chironomidae)
Xinhua
Crane Fly (Tipulidae)
Fungus Gnat (Mycetophilidae) Meniscus Midge (Dixidae)
DON’T
NEED BLOOD
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Type of Habitat
• Temporary
• Pools, depressions, containers
• Permanent
• Swamps, marshes
Type of Egg
• Single (usually desiccation resistant)
• Raft (laid on water)
Seasonal Abundance (Phenology)
Generations per year
• Single
• Multiple
Feeding Behavior
• Females only
Mosquito Life Cycle
4 Instars
Full Life Cycle can be 7 – 14 DAYS
(Temperature Dependent)
Adult ♀2 – 8+ weeks
Aquatic
Land
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48 species documented in 2005
• Dichotomous Keys
• 4th instar larvae
• Adults
Species Descriptions
• Larvae
• Adults
• County Records
• Larval Habitat
• Overwintering Stage
• Host Preference
• Virus Isolates
• Phenology
54 species documented as of 2018Available as PDF
www.ct.gov/caes
Bulletin 996
Connecticut Mosquitoes
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Vectors
• Maintenance or Amplifying
• “Bridge” – transmit from vertebrate
host to human, horse, etc.
Nuisance
• Primarily Seek Blood from Mammals
• Occasionally Infected with WNV, EEE
• Seasonal Abundance Important
Mike Thomas, CAES
“The Usual Suspects”
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Mosquito-Borne Virus Cycle
Incidental Infection
Vertebrate HostMosquitoVirus
Maintenance Cycle
Amplification Cycle
“Bridge”
Transmission Cycle
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• Main vector of West Nile virus (WNV)
Maintenance and Amplification
• Cx. pipiens = Urban and Suburban habitats
• Cx. restuans = Suburban and Rural habitats
• Egg Rafts
• High organic content
• “Containers”, Temporary pools
• Multiple generations per year
• Peak numbers in early-mid summer
• Primarily feed on BIRDS
• Occasionally on mammals
Arbovirus Isolates
Culex pipiens: WN (1,695), EEE (11)
Culex restuans: WN (330), EEE (5), JC (1)
Culex pipiens and Culex restuans
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Culex pipiens and Culex restuans• Larvae and pupae are found in a variety of habitats
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0
10
20
30
40
50A
vera
ge M
osq
uit
oes
Average Culex pipiens per Gravid Trap 2019 13 Year Mean
Culex pipiens and Culex restuans
0
4
8
12
16
20
6/2
-6/8
6/9
-6/1
5
6/1
6-6
/22
6/2
3-6
/29
6/3
0-7
/6
7/7
-7/1
3
7/1
4-7
/20
7/2
1-7
/27
7/2
8-8
/3
8/4
-8/1
0
8/1
1-8
/17
8/1
8-8
/24
8/2
5-8
/31
9/1
-9/7
9/8
-9/1
4
9/1
5-9
/21
9/2
2-9
/29
9/3
0-1
0/5
10
/6-1
0/1
2
10
/13
-10/1
9
Week
Average Culex restuans per Gravid Trap
Overwinter as
Mated Female
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Arbovirus Isolates
EEE (344), WN (117), JC (2)
• Main vector of Eastern Equine Encephalitis (EEE)
Maintenance and Amplification
• Atlantic white cedar, red maple swamps
• Egg Rafts
• Underground “crypt” habitat, formed by tree roots
• Sphagnum moss mats
• 2 -3 generations per year
• Peak numbers in mid summer
• Primarily feed on BIRDS
• Occasionally on mammals
Culiseta melanura
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Culiseta melanura
Mike Thomas, CAES
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0
5
10
15
20
25
30
35
40
456
/2-6
/8
6/9
-6/1
5
6/1
6-6
/22
6/2
3-6
/29
6/3
0-7
/6
7/7
-7/1
3
7/1
4-7
/20
7/2
1-7
/27
7/2
8-8
/3
8/4
-8/1
0
8/1
1-8
/17
8/1
8-8
/24
8/2
5-8
/31
9/1
-9/7
9/8
-9/1
4
9/1
5-9
/21
9/2
2-9
/30
9/3
1-1
0/5
10/6
-10/1
2
10
/13
-10
/19
10
/20
-10
/26
10
/27
-11
/2
# M
os
qu
ito
es
2019 22 Year Mean
Average Light Trap Collections – Cs. melanura, 2019
Overwinter as
Larvae
3 Generations
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• Bridge Vector of West Nile virus (WNV)
Transmission to Humans and Horses
• Egg rafts laid on water in brackish and freshwater habitats
• Shallow pools associated with Phragmites sp.
• Multiple generations per year
• Generalist Feeder
• Obtains blood from many
bird and mammal species
Arbovirus Isolates
EEE (16), WN (171), JC (3)
Culex salinarius
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Roger Wolfe, CT DEEP
UConn, CLEARRoger Wolfe, CT DEEP
Culex salinarius
Mike Thomas, CAES
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Culex salinarius
Overwinters as
Mated Female
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• Bridge Vector of Eastern Equine Encephalitis (EEE)
Transmission to Humans and Horses
• Single eggs laid directly on water
• Larvae attach to aquatic vegetation in freshwater habitats
• One extended generation per year
• Generalist Feeder
• Obtains blood from many
bird and mammal species
Arbovirus Isolates
EEE (10), WN (14), JC (31)2019 MA
12 human EEE cases
142 (+) pools from Cq. perturbans
Coquillettidia perturbans
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NJMCA
Tom Murray, bugguide.net
Coquillettidia perturbans
www.bio.brandeis.edu
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0
50
100
150
200
250
6/2
-6/8
6/9
-6/1
5
6/1
6-6
/22
6/2
3-6
/29
6/3
0-7
/6
7/7
-7/1
3
7/1
4-7
/20
7/2
1-7
/27
7/2
8-8
/3
8/4
-8/1
0
8/1
1-8
/17
8/1
8-8
/24
8/2
5-8
/31
9/1
-9/7
9/8
-9/1
4
9/1
5-9
/21
9/2
2-9
/30
9/3
1-1
0/5
10
/6-1
0/1
2
10
/13
-10
/19
10
/20
-10
/26
# M
os
qu
ito
es
2019 22 Year Mean
Average Light Trap Collections – Cq. perturbans, 2019
Overwinter as
Larvae
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• Primarily Nuisance mosquitoes
• Desiccation-resistant eggs
• Larvae develop in a variety of transient water
habitats
• Multiple generations per year; RAINFALL
dependent
• Primarily Feed on Mammals
• Occasionally on Birds
Arbovirus Isolates
Aedes vexans = WN (19), EEE (19), JC (16)
Ochlerotatus trivittatus = WN (4), EEE (9), JC (19)
Psorophora ferox = WN (5), EEE (5), JC (1)
“Floodwater” Species
Bugguide.net
Ae. vexans
Oc. trivittatus
Ps. ferox
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Over 11,000 Ps. ferox & Ae. vexans
Sept. 22, 2011
“Floodwater” Species
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“Floodwater” Species
Overwinter as
Eggs
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• Nuisance mosquitoes
• Most diverse group of mosquitoes in CT
• Some potential to transmit WNV and EEE
• Jamestown Canyon isolated frequently
• Eggs are desiccation resistant
• Larvae develop in a wide variety of seasonal
freshwater habitats
• Major generation in spring
• Peak abundance in early summer
• Some species with 2-3 generations
• Strong Mammalian Association
• Occasionally on Birds
Tom Murray, Bugguide.net
Sean McCann, Bugguide.net
“Vernal Pool” and “Snow-pool” Species
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Arbovirus Isolates
Oc. canadensis = WN(12), EEE(37), JC(120)
Ae. cinereus = WN(13), EEE(20), JC(12), LAC (2)
Oc. sticticus = WN(2), EEE(1), JC(25),
Oc. abserratus = JC (52)
Oc. aurifer = JC (51)
Oc. excrucians = JC (15)
Oc. provocans = JC (21)
Oc. stimulans = WNV (2), JC (23),
Oc. thibaulti = JC(4)
“Vernal Pool” and “Snow-pool” Species
2-3
Generations
1 Generation
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“Vernal Pool” and “Snow-pool” Species
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2 Generations
“Vernal Pool” and “Snow-pool” SpeciesOverwinter as
Eggs
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“Vernal Pool” and “Snow-pool” SpeciesOverwinter as
Eggs
1 Generation
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• Primarily Nuisance Mosquitoes
• Desiccation-resistant eggs laid above
waterline in containers
• Larvae develop in an wide range of natural
and artificial containers
• Multiple generations per year
• Strong Mammalian Association
• Occasionally on Birds
Arbovirus Isolates
Oc. triseriatus = WN(5), EEE (4), JC (2), LAC (3)
Oc. japonicus = WN(10), EEE (1),
Ae. albopictus = WN(2)
“Container” Species
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Natural Containers
Ochlerotatus triseriatus Ochlerotatus japonicus Aedes albopictus
“Container” Species
Artificial Containers
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“Container” Species
Overwinter as
Eggs
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• Nuisance Mosquitoes
• Larvae develop in salt marsh pools
• Desiccation-resistant eggs laid in areas
flooded by lunar tides
• Multiple generations per year
• Strong Mammalian Association
Arbovirus Isolates
Oc. sollicitans = WN (1), EEE (3), JC (6),
Oc. cantator = EEE (5), JC (81)
Oc. taeniorhynchus = WN (6), JC (17)Roger Wolfe, CT DEEP
“Salt Marsh” Species
Tom Murray, Bugguide.net
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“Salt Marsh” Species
Overwinter as
Eggs
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Questions?
203-974-8517