Mosquitology

morphology

	Anopheles	Culex	Aedes
resting	rest at an angle on wall surface	rest with body parallel to surface
adult color			black and white
larvae	no siphon	long siphon	short siphon
egg	laid singly, floating	collected in egg raft, floating	laid singly, deposited on damp surface

• Mansonia
• Coquillettidia
  • larvae siphon piercing into a root of water plants to breathe

• Haemagogous
• Sabethes
  • only in Central and South America
  • metallically colored body
  • dry tolerant eggs

mosquito-borne disease

arbovirus

• arthropod-borne virus
• family Togaviridae, Flaviviridae, Bunyaviridae, Reoviridae, Rhabdoviridae

Aedes-borne disease

• 932 species in the world
• 40 species transmit pathogens

• dengue
• yellow fever
• chikungunya
• zika

Aedes aegypti	Aedes albopictus
yellow fever mosquito	asian tiger mosquito
crescend-shaped white scale lines	straight white line
prefer small water containers to breed
feed blood in daytime
laid eggs on damp surface eggs resistant to desiccation, eggs alive 3-6 months under dry condition
only in tropics and subtropics	worldwide including temperate region
prefers urban area	prefers transitional to rural area
prefers inside house	prefers outside
originated from Africa	originated from Asia
	produce diapause eggs

• diapause eggs of A. albopictus
  • eggs laid during winter are resistant to dry as well as cold environment
  • premature larvae developed and stop developing during winter
  • female albopictus produce diapause when sunlight duration gets shorter and temperature lower
  • individuals living in areas northern to tropic of Cancer produce diapause eggs
    • ones living in tropics never produce diapause eggs

bridging vector

• vectors that transmit pathogen from infected wild animals and subsequently transmit the pathogen to humans
  • not always prefer human to feed, nor live close to human
• yellow fever vectors in savannah cycle between sylvatic cycle and urban cycle are bridging vector
  • spillout of pathogen from animal

Culex-borne disease

• Culex tritaeniorhyncus
  • JEV - Cx. tritaeniorhyncus is bridging vector

• Cx. pipiens complex
  • 4 subspecies
  • West Nile virus - Cx. pipiens complex are bridging vectors
  • hybridazation of Culex may have brought introduction of WNV into North America
  • Lymphatic filariasis
    • Wuchereria bancrofti
      • human is only host
    • Brugia malayi
    • Brugia timori
    • various Culex species are attributable to transmission of microfilaria

Anopheles

Morphology

• 肢にwhite spotsが多数ある
• Anophelesのlarvaeは水面近くで横向きに浮く
  • AedesとCulexのlarvaeは頭が下
• ova is boat-shaped, laid and floated singly on water surface

Blood-sucking activity

• completely nocturnal

Vector function

• Only 30-40 species transmit human malaria

anopheles in Africa

• An. gambiae complex
  • 8 species in all
  • morphologically similar
  • prevalent broadly in sub-Saharan Africa
    • An. gambiae sensu stricto (s.s.)
    • An. arabiensis (except around DRC)
  • prevalent only eastern Africa
    • An. merus
  • prevalent only western Africa
    • An. melas

• An. funestus group
  • 9 species in all
  • morphologically distinguishable
  • most important
    • An. funestus s.s.

tendency

	An. arabiensis	An. gambiae	An. funestus
Blood meal preference	more of livestock	more of human
Adult resting site	more outdoor	more indoor
Breeding site	small and open		large and vegi