1. This document classifies medically important arthropods into classes including insects, arachnids, and other classes. 2. Within the class insecta, it describes different types of flies, mosquitoes, bugs, lice, fleas, and ticks that can transmit diseases like malaria, dengue, plague, and more. 3. Within the class arachnida, it outlines mites, spiders, scorpions, and ticks/mites that can cause conditions such as scabies, scrub typhus, and allergic reactions.

1. ssification of Medically Important Arthropo
Class Insecta Class Other
Arachnida Classes
Lice (blood) Fleas (blood) Bugs (blood) Flies –except 1
(blood)
Mosquitoes (blood)
Head louse Oriental/tropical Bed bug Sandfly –slender long legs, erected wings on resting
Pediculus humanus rat flea Cimex lectularius Phlebotomus –old world sandfly
Xenopsylla cheopis Lutzomyia –new world sandfly
var. capitis Cimex hemipterus leishmaniasis,
pediculosis plague (Yersinia pestis), allergy, bartonellosis,
endemic typhus (Rickettsia typhi), sandfly fever –a viral disease like flu.
host of Hymenolepis IIry bac. infection.
Body louse Black fly/Buffalo gnats humpbacked appearance
(Family Reduviidae)
tapeworms Reduviid bug Simulium
Pediculus humanus [H.nana–dwarf, H.diminuta–rat]. (kissing bugs),
Rhodnius, Triatoma Onchocerciasis/river blindness
var. corporis Northern rat flea (Onchocerca volvulus) –not in Sri Lanka.
Panstrongylus.
pediculosis, Nosopsyllus fasciatus Tsetse fly
American Glossina
epidemic typhus endemic typhus
(Rickettsia prowazekii), (Rickettsia typhi). trypanosomiasis African Trypanosomiasis
(Chagas' disease) (Sleeping sickness) (Trypanosoma brucei
trench fever Human flea (Trypanosoma cruzi).
–T.b. rhodesiense, T.b. gambiense)
(Bartonella quintana), Pulex irritans Deer fly/Yellow fly
skin irritation - female fleas Transmission from Reduviid bugs: Chrysops
relapsing fever Reduviid bugs defecate while feeding
(Borrelia recurrentis). burrows into human skin for → faeces contain trypanosoma (Loa loa),
laying eggs, Loiasis
intermediate host of → scratching → spread of Tularaemia (Francisella tularensis).
Pubic/Crab louse Hymenolepis & faeces around site of bite → domesticaDomestic fly (non-blood)
Dipylidium tapeworm trypanosoma enter through site Musca
Phthirus pubis mechanical vector –transmits several viral
pediculosis, larvae, ?plague. of bite. Bacterial & parasitic diseases (swallow & regurgitate
sexually transmitted Transmission of Plague from fleas: manner) –Ascariasis, Amoebiasis,
(pubic/perineal flea is infected with Y.pestis → bacteria myiasis.
obstruct the oesophagus of the flea → when
/eyelash/armpit hairs) draw blood from rat/human → cannot
flea
swallow → regurgitate blood with Y.pestis Mosquitoes (blood)
Anopheline Culicine Mansonia
Anopheles culicifacies Mansonia spp.
clear, stagnant/sluggishly Culex Aedes rural vector
moving water (drying river – dusk & dawn biters
breeds on the undersurface
banks, gem pits, rock pools) Aedes aegypti
rest at an angle to the urban vector of water plants (eg: Salvinia)
resting surface. man-made small collections Brugian filariasis (Brugia malayi)
Malaria. of clear water (tires, tins, Transmits Dirofilaria repens
plastic/glass containers,
flower vases, blocked drains etc.) (a filarial nematode).
Filarial J.E. Aedes albopictus
rural vector
Culex quinquefasciatus Culex gelidus small collections
polluted, stagnant water husk pits of natural, clear
Lymphatic filariasis Culex tritaeniorhynchus water (tree stumps, leaves etc.)
(Wuchereria bancrofti).
Culex fuscocephala Dengue (DF & DHF),
paddy fields
Yellow fever,
Japanese Encephalitis.
Chikungunya.
Class Arachnida Other Classes
Class Crustacea
Ticks (blood) Mites Spiders & Cyclops
Scorpions Intermediate host of
Soft Ticks Itch mite  mildly venomous Guinea worm
(Family Argasidae) Sarcoptes scabiei  local signs around bite wound (Dracunculus medinensis)
Argus spp. Scabies.  rarely – severe reaction with & fish tape worm
Allergic reactions; Chiggers/Red “bugs” extensive tissue necrosis (Diphyllobothrium latum)
Tick paralysis –in animals & humans; Trombicula larva Fresh water crabs & Crayfishes
Viral – Colorado tick fever, Intermediate host of
scrub typhus
Crimean-Congo fever; (Orientia tsutsugamushi), lung fluke (Paragonimus westermani)
Bacterial – Rocky mountain Lobsters
irritating dermatitis.
spotted fever, tick borne Shrimps
typhus, Q fever; House dust mite
Parasitic – Babesiosis. Dermatophagoides pteronyssinus (European house dust mite)
Hard Ticks Dermatophagoides farinae (American house dust mite) Class Myriapoda
(Family Ixodidae) Euroglyphus maynei Centipedes
Ixodes sp.. Asthma & allergic symptoms. non-fatal, painful swelling
all disease under soft ticks, their gut contains potent digestive enzymes (notably proteases) that around site of “bite”.
Lyme disease (Borrelia burgdorferi). persist in their feces and are major inducers of allergic reactions
such as wheezing.
their exoskeleton can also contribute to allergic reactions © Garaka Rabel – 2012