biology, ecology, and feeding behavior of mosquitoes in ... · 3/9/2020 · mosquito life cycle 4...

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

• 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

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

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

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

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”

Mosquito-Borne Virus Cycle

Incidental Infection

Vertebrate HostMosquitoVirus

Maintenance Cycle

Amplification Cycle

“Bridge”

Transmission Cycle

• 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

Culex pipiens and Culex restuans• Larvae and pupae are found in a variety of habitats

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

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5

6/1

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/22

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/29

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3

7/1

4-7

/20

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1-7

/27

7/2

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/3

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-8/1

0

8/1

1-8

/17

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/24

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/31

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-9/1

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/21

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2-9

/29

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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

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

Culiseta melanura

Mike Thomas, CAES

0

5

10

15

20

25

30

35

40

456

/2-6

/8

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-6/1

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6/1

6-6

/22

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3-6

/29

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/6

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7/1

4-7

/20

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1-7

/27

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/3

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8/1

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/17

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8-8

/24

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/31

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-9/7

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-9/1

4

9/1

5-9

/21

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/30

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1-1

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-10/1

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10

/13

-10

/19

10

/20

-10

/26

10

/27

-11

/2

# M

os

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ito

es

2019 22 Year Mean

Average Light Trap Collections – Cs. melanura, 2019

Overwinter as

Larvae

3 Generations

• 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.


• Generalist Feeder

• Obtains blood from many

bird and mammal species

Arbovirus Isolates

EEE (16), WN (171), JC (3)

Culex salinarius

Roger Wolfe, CT DEEP

UConn, CLEARRoger Wolfe, CT DEEP

Culex salinarius

Mike Thomas, CAES

Culex salinarius

Overwinters as

Mated Female

• 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

NJMCA

Tom Murray, bugguide.net

Coquillettidia perturbans

www.bio.brandeis.edu

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

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/31

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-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

• 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

Over 11,000 Ps. ferox & Ae. vexans

Sept. 22, 2011



Overwinter as

Eggs

• 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



Sean McCann, Bugguide.net

“Vernal Pool” and “Snow-pool” Species

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)


2-3

Generations

1 Generation

2 Generations

“Vernal Pool” and “Snow-pool” SpeciesOverwinter as

Eggs

“Vernal Pool” and “Snow-pool” SpeciesOverwinter as

Eggs

1 Generation

• Primarily Nuisance Mosquitoes

• Desiccation-resistant eggs laid above

waterline in containers

• Larvae develop in an wide range of natural

and artificial containers




Arbovirus Isolates

Oc. triseriatus = WN(5), EEE (4), JC (2), LAC (3)

Oc. japonicus = WN(10), EEE (1),

Ae. albopictus = WN(2)

“Container” Species

Natural Containers

Ochlerotatus triseriatus Ochlerotatus japonicus Aedes albopictus


Artificial Containers


Overwinter as

Eggs

• Nuisance Mosquitoes

• Larvae develop in salt marsh pools

• Desiccation-resistant eggs laid in areas

flooded by lunar tides



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


“Salt Marsh” Species

Overwinter as

Eggs

Questions?

[email protected]

203-974-8517

biology, ecology, and feeding behavior of mosquitoes in ... · 3/9/2020 · mosquito life cycle 4...

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