Exam Review

Mosquitoes

AnnouncementsSpeakers Today: Marty Whitehouse, Laura StrasingerSpeakers Next Thursday: Sarah Stephan, Chris GibsonRead Chap 14, Mosquitoes

Mosquitoes

• Mosquitoes are flies (Diptera, they have 2 wings)

• Family Culicidae

• Larval and pupal stages are always aquatic

• Wings are covered in scales

• Mouthparts of females are adapted for piercing and sucking blood

The Business End

• Palps & antennae are used to find hosts

• Once the mosquito lands, the outer sheath slides back, exposing the mandilbes & maxillae

• These form the stylets which stab the skin.

• Sensors on the tip of the stylets confirm capillary location

Sensory Setae

Human Hair

Blood Capillary

Sensors

Lower “Lip” (labium)

Palp

Mandibles & Maxillae

Compound Eye

There are many species of mosquitoes

• About 2,500 species world-wide• About 150 in North America• 50 – 60 in Kentucky• Each species has its own biology, behavior,

ecology, etc.• Implications:

– No single control can be expected to work for all mosquitoes

– Need to understand which species that you’re facing

Five Principal Genera in Kentucky

• Aedes – Most anthropophillic• Anopheles – Malaria mosquitoes• Culex – Orniphilic, disease threats• Ochlerotatus – Important invaders• Psorophora – Large, painful biters

• The dominant species you face depends on where you are.

Northern Kentucky, 2004Boone

Fleming

20

40

60

140

144

24 25 26 270

4

8

24

Campbell

Grant

5

10

49

24 25 26 270

7.5

15

30

45

Week

No

. mo

squ

itoes

Cx. Pipiens/restuansCulex spp.Aedes spp.Ochlerotatus spp.Anopheles spp.Psorophora spp.

Western Kentucky, 2004Daviess Fulton

Union 24 25 26 270

75

150

663

10

20

80

130

180

24 25 26 270.00

12.50

25.00

Week

No

. mo

squ

itoes

Cx. Pipiens/restuansCulex spp.Aedes spp.Ochlerotatus spp.Anopheles spp.Psorophora spp.

Urban Kentucky, 2004

24 25 26 270

10

20

30

40

50

800850900

No

. mo

squ

itoes

Week

Fayette JeffersonCx. Pipiens/restuansAedes spp.Ochlerotatus spp.

23 24 25 260

25

50

75

990

Aedes vs. Culex Biology

Aedes/Ochlerotatus Culex

Primary nuisance, very numerous

Primary virus vectors

Attacks mammals Attacks birds, few human bites

Daytime – early evening Late night – early morning

Lays eggs singly adjacent to water

Lays eggs in rafts on water surface

Overwinters as eggs Overwinters as adults

Daytime resting sites < 10 ft (bushes)

Daytime resting sites > 10 ft (trees)

Anopheles and Psorophora cross these categories

Top 10 Mosquitoes in Kentucky

5 Major GeneraAedes

Anopheles

Culex

Ochlerotatus

Psorophora

Other Genera in KY:Culiseta

Toxorhynchites

Uranotaenia

Coquillittidia

Orthopodomyia

Wyeomyia

#1 Aedes albopictus

• Asian tiger mosquito• Nuisance biter, potential dengue vector• Feeds evenings, mornings on humans

#2 Aedes vexans

• Inland flood water mosquito• Nuisance biter, transmits dog heartworm, WEE/EEE• Feeds at dusk

#3 Culex pipiens/restuans

• Northern house mosquito• Most likely to transmit WNV• Feeds at night on birds, humans

#4 Ochlerotatus japonicus

• Asian bush mosquito• Currently invading state• Begins biting mid-morning, lower extremities

#5 Ochlerotatus triseriatus

• Eastern treehole mosquito• Vector of La Cross encephalitis• Feeds at dusk on small mammals, humans to lesser extent

#6 Anopheles punctipennis

• Mottled-wing Anopheles• Aggressive nuisance biter• Feeds during the day/dusk in shady/forested areas

#7 Anopheles quadrimaculatus/crucians

• Common malaria mosquito (quadrimac.)• Vector of dog heartworm• Feeds during day/dusk in shady/forested areas

#8 Ochlerotatus trivittatus

• Three-striped mosquito• Aggressive nuisance biter, especially when hot, after rain• Particularly prevalent in flooded woodlands• Feeds during the day, dusk

#9 Psorophora ciliata/howardii

• Gallinipper• Ouch!!• Feeds during the day, at night

#10 Culex erraticus

• Weak flier, feeds mostly on forest animals• May feed on humans when present

Generic Mosquito Life Cycle

• Larvae are wigglers

• Pupae are tumblers (quite active)

• Both breath air

• Eggs are laid on the surface of water in rafts (Culex) or singly (Anopheles) or near water (Aedes)

Most breath atmospheric air via a siphon

Mosquito Diet

• Most Larvae feed on algae but a few are predaceous and feed on other mosquito larvae

• Only females are blood sucking

• Males and females feed on nectar and other plant juices

After Emergence …

• Day 1 – Rest on nearest available moist/shady spot. Vertical surfaces.

• Day 2 – Carbohydrate feeding

• Day 2/3 – First blood meal

• Next Day – First egg clutch

• After egg clutch, more carbohydrate & blood meals

• Typical adult lives 7 – 10 days