Entomology Lecture Handout

PARASITOLOGY Parasitology - study of the life cycle, morphology, pathogenecity, transmission, epidemiology, and control (diagnosis, treatment, and prevention) of parasites History •17th century - mostly external parasites; few external parasites (large) •Francesco Redi - grandfather of Parasitology •Demonstrated obligatory parenthood in parasites •Leeuwenhoek - described various kinds of microscopic animals •Linnaeus - described and classified the helminths •Rudolphi - gave scientific names to parasitic worms •Leuckart - demonstrated that insects serve as

intermediate hosts and vectors of parasites •First nematodes recorded in the Philippines by Schneider (German biologist) Auchenatha corrolata - from the flying lemur (Cyanocephalus volans) Gnathostoma spinigerum - from the Philippine Civet cat (Paradoxorus philippinensis) •Trypanosoma evansi - first pathogenic protozoan parasite recorded in the Philippines in horses imported from India •Liborio Gomez - grandfather of Philippine Parasitology •Candido Africa (MD) and Marcos Tubangui (DVM) fathers of parasitology

INTRODUCTION 3 Categories of Symbiosis: 1. Mutualism - there is reciprocal advantage derived from the union e.g. flagellate (Trichonympha campamula) and wood termite (Temopsis nevadensis). Flagellate digest wood particle for the termite while the latter gives protecti9on to the former.

2. Commensalisms - only one symbiont is benefited although the other suffers no harm e.g. Entamoeba coli and small intestine of man. 3. Parasitism - one symbiont receives the advantages to the detriment of the other e.g. Ascaris suis and pig

Parasite - an organism which for the purpose of procuring food and shelter, visits briefly or take up abode temporarily or permanently outside or inside the body of another organism where it usually does harm. The symbiont receiving the advantage is known as the parasite while the injured/harmed is the host. KINDS OF PARASITES 1. Optional occasional parasite - parasite that briefly visits their host to obtain nourishment but not dependent upon them for either nourishment or shelter e.g. mosquitoes, sandflies 2. Obligate occasional parasites - those that do not permanently live upon their host but are dependent upon them for nourishment and to some extent for shelter e.g. fleas and ticks 3. Determinate transitory - parasitism is limited to a definite stage or stages in their life cycle, during which time, parasitism is obligate or continuous e.g. botflies, marble flies e.g. larva of dipteran flies which are deposited in dead or living tissue 4. Permanent parasite - parasitism extends from the time of hatching of the eggs to the time that the eggs are produced by the adult e.g. lice and mange mite 5. Fixed parasite - parasites that can not pass spontaneously from one host to the other e.g. helminthes 6. Erratic parasite - those that occur in organs far remoter from their normal location e.g. Ascaris suis in the fallopian tube, bile ducts of pigs; Stephanurus dentatus in the lungs

7. Monoxenous parasite - those that require only one host to complete their life cycle e.g. Ascaridia galli in chicken and Trichuris vulpis in dogs 8. Heteroxeneous parasite - those that require 2 or more hosts to complete their life cycle - If 2 or more hosts are required, that host wherein sexual maturity (eggs and oocysts are formed) is reached is known as the primary host, definitive or final host; the other host in which the parasite undergoes juvenile or larval development of asexual multiplication in the secondary or intermediate host e.g. Plasmodium sp - final host - mosquito; man - intermediate host Fasciola gigantica - final host - cattle, goat; snail - intermediate host Paragonimus westermani - final host – man; snail - 1st i.h.; crab - 2nd i.h) 9. Pseudoparasites - objects which are often mistaken for true parasite eggs and larvae because it resembles them e.g. pollen grain, fungal spores, yeast cells, plant spines 10.Ectoparasites or external parasites - parasites occurring on the surface of the body e.g. ticks, lice, mites. 1

Infestation - condition produced by external parasites 11.Endoparasites or internal parasites - parasites found in the alimentary canal, blood, muscle, and other tissues of the host and the condition is term as infection e.g. roundworms, Plasmodia, coccidian 12.Facultative parasites - parasites that could exist both as free-living or parasitic e.g. larva of blowflies and flesh flies in tissues or wounds causing myiasis or in decomposing organic matter 13.Reservoir hosts - final hosts that harbor the infection but show no outward sign of infection. They serve as 'carriers', the organism multiply but not enough to cause a disease e.g. Trypanosoma evansi in carabaos 14. Transport or paratenic host - unnatural hosts in which parasites are accidentally lodged and transmission is though ingestion of paratenic host. Parasites remain in a dormant or suspended/inhibited stage (no development and multiplication) e.g. Toxocara eggs ingested by rats Transmission of Disease by Arthropods 1. Mechanical / Non-cyclical transmission - when no change in form or development occur in the arthropod body e.g T. evansi; amoeba; helminth ova 2. Biological transmission / Cyclical transmission there is change in form or development of the parasite or orgaism in the body of the arthropod >Types of Biological Transmission: 1. Cyclopropagative transmission - the organism undergoes cyclical changes or change in form as well as in number (multiplication) in the body of the arthropod e.g Plasmodia in mosquito 2. Cyclodevelopmental transmission the organism undergoes cyclic development changing in form and size but no change in number, no multiplication in the body of the arthropod e.g. Dirofilaria immitis in the mosquito 3. Propagative transmission - the organism undergoes multiplication in the arthropod but there is no cyclical development or change in form and size e.g. Pasteurella pestis in the gut of the rat flea

or birds (paratenic hosts), when they are eaten by the susceptible host the encysted larva develop into the adult 15.Prepatent period - time of infection to the time eggs or larvae are demonstrated/produced in the feces to the time eggs disappear 16.Parasitic zoonoses - parasite transferable from animal to man and vice versa for parasites affecting man and animals e.g. Trichenella spiralis, Entamoeba histolytica 17.Parasitemia - presence of parasites in the blood 18.Zooparasite - parasite that is highly specific for animals e.g. Oxyuris equi 19.Anthropoparasite - highly specific parasite for man e.g. Enterobius vermicularis 20.Anthropozooparasite - equally specific for man and animals e.g. Trichinella spiralis 21.Enzoonoses - man is essential for the life cycle of the parasite e.g. Taenia solium; T. saginata 22.Parazoonoses - unstable and changeable group; man is just accidentally involved e.g. Ascaris suis

(Bubonic plague) 3. Transovarian transmission or hereditary transmission - transmission of infection is through the next generation of ticks. After the mature female tick ingests the parasite, the parasite invades the developing tick egg and when the young tick emerges, it carries with it the infective organism, then the mother dies after laying eggs e.g. Babesia in tick 4. Transtadial - organism is transmitted by the next developmental stage of ticks 5. Phoresy - transport of small parasite (lice and mites) by bigger parasite (flies, mosquitoes). Eggs of some flies are attached to abdomen of another fly, becomes hatched then deposited or transferred in another host e.g. Dermatobia hominis egg in the abdomen of mosquito; when Tabanus feeds, it could have lice attached to its leg and transfer it to another host

Factors that influence the degree of harm done by various parasites are as follows: 1. Number of parasites present 3. nature of their food 5. Age of the host 2. location of the parasite 4. movement of parasites 6. Virulence of the parasite Effects of parasitic life on the parasites: 1. Loss of certain sense organs - eye spots in some external parasites (Melophagus ovinus) 2. Loss of wings - bedbugs, lice 3. Loss of alimentary canal – tapeworms 4. Special development of some organs or adhesions 5. Special development of organ of reproduction for fecundity. Some flukes lay 250,000 to 2 million eggs/day. Reproductive organs occupy 2/3 of the body cavity in general

6. Sexual dimorphism - female are larger than male 7. Complex life cycle - need for the intermediate host to increase chances of perpetuating species; multiplication in the i.h. 8. Greatly alters metabolism (some parasites can live anaerobically). Internal parasites that live anaerobically obtain energy by converting glycogen into fat. Internal parasite absorbs nutrients and vitamins from the host body. 2

9. Stay

in

the

dormant/inhibited

stage

in

the

unnatural host (paratenic host) or even in the natural host (hypobiosis)

1. Absorb part of the digested nutrients, vitamins, and minerals 2. Suck blood or lymph 3. Mechanical obstruction or pressure 4. Growth of nodules 5. Development of tumors 6. Cause wounds 7. Destruction of tissues 8. Irritation and annoyance - interferes with feeding which lead to loss of wt / meat / milk 9. Secretion of toxins and other harmful substances a. Anti-digestive enzymes

b. Digestive enzymes harmful to host tissue c. Anti-coagulatory and hemolytic enzymes d. Other secretions and excretions and body fluids Transmits causal agents of some infectious diseases Reduce the resistance of the host to other infections Cause allergy (local or general) Serve as intermediate host and cyclic transmitter of certain parasites Abortion, infertility, lowered productive and reproductive performance Decreases feed conversion efficiency

Pathogenic Effects of parasites

10. 11. 12. 13. 14. 15.

Host specificity - parasite species associate only with one species of host, and if a parasite has more than one host, these hosts are usually closely related; only few parasites can live in a variety or a wide range of hosts Organ specificity - each species of parasite has its predilection site in or on the host

ENTOMOLOGY Entomology - the study of arthropods and allied insects General Characteristics of Arthropods: 1. bilaterally symmetrical (appendages are always paired)

2. body divided into head, thorax, and abdomen

General structure and function I. Integument - the body is covered by chitin; this forms the typical body segment (sclerite) which are divided into tergum (dorsal), sternum (ventral), and pleuron (lateral) II. Circulation - the hemocoele is a space full of blood which bathes all body organs; the system is composed of an enlarged dorsal blood vessel (heart), pericardium (encloses the heart), paired ostia (opening in the pericardial walls), and short arteries III. Respiration - the arthropod may possess any or 2 of these short arteries a. Gills (bronchiae) - found in larva, nymph, and adult aquatic species of various kinds b. Trachea - fine elastic tubes in the chitinous lining which branches and ramifies among the internal organs c. Lung book - found in spiders d. Gill book - found in crabs e. Spiracle - smaller circular opening in the

3. joined with appendages

exoskeleton IV. Digestion a. Foregut or stomodeum - buccal cavity, pharynx, proventriculus, gizzard; involved in ingestion, passage, and disintegration of food particles b. Midgut or mesenteron - storage of food and enzyme secretion c. Hindgut or proctodeum - absorption of food and expulsion of fecal materials V. Excretion a. Paired nephridia – crustaceans b. Malpighian tubules – insects c. Coxal glands VI. Nervous system a. Supraesophageal center (brain) b. Ganlionated ventral nerve cord VII. Reproduction a. Male - paired testes, vas deferens, paired seminal vesicle, penile organ b. Female - paired ovaries, oviduct, uterus, vagina, spermatheca

Types of Development 1. Direct / incomplete metamorphosis / hemimetabolous life cycle - 1 or 2 of the stages are missing with the exception of the adult; hatched insect (nymph) is a miniature of the adult e.g. lice, bedbugs 2. Indirect / Complete metamorphosis / holometabolous life cycle - characterized by having the 4 stages: egg, larva, pupa, adult; the hatched insect differs morphologically from parent. Each form of the insect after each ecdyses is known as the instar e.g. mosquitoes 3

Stages in the Life Cycle of an Arthropod 1. egg - stage that undergoes a series of segmentation 2. larva - developing form after it has emerged from the egg and before it is transformed into a pupa; it is the feeding stage of the parasite 3. pupa - the quiescent stage of metamorphosis that

emerge from the larval stage 4. nymph - form that leaves the egg with similarity in morophology with that of the adult 5. adult - the reproductive stage of the parasite 6. imago - the young adult

Types of larva: 1. Polypod - larva with a marked head, a 3segmented thorax with legs, a 10-sefmented abdomen and pairs of abdominal legs or fleshy hooked legs e.g. caterpillars

2. oligopod - larva with a well-marked head, 3 pairs of thoracic legs, but no abdominal legs e.g. beetles 3. apodous - larva with no legs on the thorax and abdomen e.g. maggots

Types of Pupa: 1. Free or exarate - the wings and legs are free from the body and can be seen externally e.g. beetles 2. Obtectate - pupa with legs and wings bound to the body by molting fluid but still visible externally

e.g. mosquitoes 3. Coarctate - last larval skin retained; this hardened skin (puparium) encloses the pupa, hence it cannot be seen externally

Types of Female 1. Oviparous - lay undeveloped eggs e.g. housefly, stable fly 2. Ovoviviparous - lays larvated egg 3. Viviparous / larviparous - lays fully-developed General Classes of Arthropods 1. Crustacea main body divisions are cephalothorax and abdomen; legs are found on thoracic and abdominal segments 2. Arachnida - adults with 4 pairs of legs; 2 pairs of mouthparts without antennae and wings 3. Pentastomida - adults without legs except 2 pairs of hooks near the mouth, larvae with 2 leg pairs 4. Insecta - largest group; adults with 3 pairs of legs; body divided into 3 main parts: head, thorax and

larva e.g. flesh flies, tsetse flies, Oestrus ovis 4. Pupiparous - lays larva that immediately turns into pupa e.g. pigeon louse fly 5. Parthenogenetic - reproduce without males / fertilization e.g. silkworm, Strongyloides sp abdomen 5. Myriapoda a. Diplopoda - elongated, cylindrical body, terrestrial with numerous segments, each bearing 2 pairs of legs, with a pair of antennae b. Chilopoda - long, narrow, and dorsoventrally flattened; body with several segments each bearing a pair of jointed legs

CLASS INSECTA General characteristics 1. Body divided into head, thorax, and abdomen 2. 3 pairs of legs attached to the thorax and 2 pairs of wings attached to the 2nd and 3rd thoracic segment

3. Veins - wings with hollow tubes which are useful for identification 4. The body is a rigid exoskeleton which is a deposition of chitin

Classification of mouthparts 1. mandibulate (chewing) - Orthoptera, Diptera 2. haustellate (sucking) - Diptera, Hymenoptera

General Anatomy of Insects 1. Nervous system - large ganglion (brain), thoracic and abdominal ganglia, lateral nerve fibers 2. Circulatory system -large dorsal tube (heart) and

3. piercing - Siphonaptera, Diptera 4. non-piercing / reduced / non-functional Hymenoptera and certain Lepidoptera

valves; blood consists of watery fluid (serum or plasma) and white corpuscles which are colorless or greenish yellow 3. Respiratory system - tracheae, tracheoles, 4

spiracles or stigmata 4. Digestive system a. Foregut or stomodeum - mouth, pharynx, esophagus, crop and gizzard / proventriculus b. Hindgut or proctodeum - colon, rectum, anus, malpighian tubules c. Midgut or mesenteron - midintestine connects the stomodeum to the proctodeum

5. Reproductive system a. Male reproductive system - testes, vas deferens, accessory organ, seminal vesicle, ejaculatory duct, penis or aedeagus b. Female reproductive system - ovaries, oviduct, vagina, ovipositor, spermatheca (most insects)

Orders of Veterinary Importance under Class Insecta 1. Diptera - true flies 2. Hymenoptera - bees, wasp 3. Coleoptera – beetles

4. Siphonaptera – fleas 5. Orthoptera – cockroaches 6. Hemiptera – bugs

7. Phthiraptera - lice

ORDER DIPTERA (TRUE FLIES) General Characteristics 1. well-developed anterior wings; posterior wing represented by haltere (organ of balance) 2. wings with hollow tubes called veins 3. mouthparts adapted for sucking; haustellum (sucking

tube) formed by labrum and labium within which are the mandible and maxilla; in some species, mandibles and maxilla are modified for piercing 4. complete metamorphosis

Suborder of Veterinary importance 1. Nematocera

2. Brachycera

3. Cyclorrhapha

SUBORDER: NEMATOCERA General Characteristics: 1. antenna usually longer than head and thorax; more than 8 segments; wings without cross veins 2. larva and pupa are aquatic Family: •Culicidae - mosquitoes •Ceratopogonidae - biting midges

3. larva with well-developed head and mandible; bite horizontally 4. obtectate pupa •Psychodidae - sandflies •Simuliidae - black flies

SUBORDER: BRACHYCERA General Characteristics 1. antenna shorter than thorax; 3-8 segments 2. arista usually absent; if present, located terminally 3. maxillary palps held stiffly forward 4. wings with cross veins

5. abdomen with 7 visible segments 6. larva with incomplete retractile head 7. obtectate pupa

Family: Tabanidae

SUBORDER: CYCLORRHAPHA 1. 2. 3.

antenna with 3 segments arista present, located dorsally small maxillary palps

4. 5. 6.

wings with limited cross veins abdomen less than 7 visible segments larvae with vestigial head; apodous 5

7.

mouthpart has simple hooks used for tearing debris

Family: •Muscidae •Glossinidae •Calliphoridae

8.

coarctate pupa

•Sarcophagidae •Oestridae •Cuterebridae

•Gasterophilidae •Hippoboscidae

SUBORDER: NEMATOCERA CULICIDAE (MOSQUITOES) Characteristics: 1. slender insects 2. larvae and pupa are both aquatic and active 3. scales are present on the head, thorax, abdomen, legs, and wings 4. antenna plumose in male and pilose in female 5. head is spherical and the mouthparts form the long, slender proboscis 6. only female are blood sucking; male subsist on

juices of flowers and fruits 7. proboscis consists of the mandibles and maxillae which are the piercing instruments enclosed in the upper lip called labrum epipharynx and the lower lip, the labium; it also encloses the hypopharynx; the tip of the labium is modified to form the labellum; mandibles are absent in the male mosquito

Genera of Veterinary and Medical Importance: 1. Anopheles (A. maculippennis) 4. Mansonia sp. 2. Culex (C. pipiens) 5. Theobaldia sp. 3. Aedes (A. aegypti) 6. Orthopodomyia sp. TABLE 1: Differential characteristics of Anopheles, Aedes and Culex mosquitoes Anopheles sp. Aedes sp. Egg Laid singly with lateral floats Laid singly without lateral floats Larvae Lies parallel to the water surface; no Hangs diagonally from the siphon tube water surface Pupa Short and stout breathing trumpet Long and narrow breathing trumpet Adult palpi Female palp is as long as the Palp of female is shorter proboscis than the proboscis Resting Diagonal against the landing surface Parallel to the landing position surface Feeding Crepuscular Diurnal

7. Myzorhynchus sp. 8. Taeniorhynchus sp. 9. Luzonia sp. Culex sp. Laid inmass (egg raft) Hangs diagonally from the water surface Long and narrow breathing trumpet Palp of female is shorter than the proboscis Parallel to the landing surface Nocturnal

Life cycle: Eggs laid on the surface of water or on floating vegetable matter  eggs hatch in 16-24 hours into larvae or wrigglers  larvae feed on algae but others are carnivorous; they breathe through a siphon tube  larva molts 4 times in about 7 days  becomes an obtectate pupa or thumbler; they breathe through a trumpet; it does not feed  imago emerges after 2-3 days then sucks blood after 24 hours  lay eggs after about a week. Life span of mosquito - 15 to 20 days under favorable conditions; longer period if otherwise

Life cycle of anopheles mosquito

6

Feeding period of mosquitoes: A. Nocturnal - active at night time or in the dark e.g. Culex

B. Diurnal - active at day time e.g. Aedes

C. Crepuscular - active twilight e.g. Anopheles

at

Pathonegenic Effects of Mosquito 1. annoyance and blood loss 2. decreased milk and meat production 3. serve as intermediate host of several parasites: a) filarial parasite • Wucheraria bancrofti - Culex, Aedes, Anopheles (elephantiasis) • Dirofilaria immitis - Culex, Anopheles (heartworm) b) Malaria parasite (Plasmodia) • Plasmodium juxtanucleare and P. gallinaceum (avian malaria) -

Culex, Aedes • Simian malaria - Aedes 4. serve as mechanical carriers of pathogenic bacterial and viral diseases a. fowl pox - Culex, Aedes b. viral encephalitis - Culex pipiens c. yellow fever - Aedes aegypti d. H-fever - Aedes aegypti e. Dengue - Aedes aegypti f. Tularemia - Anopheles, Aedes g. Fowl cholera - Culex

Control of mosquitoes 1. Physical means a. Destruction of breeding places • Drain stagnant pools • Dispose empty cans / containers • Clear breeding places of vegetation b. Screen stables, barns, and animal houses 2. Chemical means a. Spray breeding places with appropriate

insecticides • 1.0% dieldrin • 2.0% lindane • 0.5% gm/ha malathion b. cover pond surface with petroleum or kerosene c. saturate sawdust with 2.0% DDT in diesel oil and scatter upstream d. use of mosquito repellents

Biological control a. Use of predators like fish and ducks to control larvae and pupa b. Use of bacteria (Bacillus thuringiensis) to kill

larva and pupa c. Use of protozoan parasites (Microsporidia sp) d. Sterile male technique e. Use of chemical sterilant

CERATOPOGONIDAE (MIDGES) Genus: Culicoides 1. very small; 1-3 mm long; can pass through mosquito screens

2. thorax humped over the head 3. wings oval in shape; usually spotted; no scales but 7

hairs 4. long antenna (14 segments); plumose in male, Species: Culicoides arakawae C. damnosus

pilose in female 5. short proboscis; only female are blood sucking

C. palawanensis C. pungens

C. baisasae

Life cycle: Eggs laid in objects partly submerged in water  hatch into larva in a few days; worm-like with 3 thoracic and 9 abdominal segments; feeds on tiny aquatic nematodes  obtectate pupa emerges after 1-2 weeks; covered with spines and tubercles  adult develops in few days Importance: 1. bites cause itching and swelling 2. causes allergic dermatitis in horses (Queensland itch) - Culicoides robersi 3. serve as i.h. of filarial worms in man: Dipetalonema and Manzonella spp; in animals:

4. 5. 6. 7.

Control: 1. screen treated with insecticide to repel entry 2. application of 5% dieldrin in breeding places

3. spray with adulticide (chlordane, lindane, dichlorvos, endrin, parathion)

Onchocerca in cattle and horses Intermediate host of Leucocytozoon caulleryi transmits Blue tongue in sheep transmits fowl pox virus Nocturnal

SIMULIIDAE (BLACKFLIES, BUFFALO GNATS) Genus: Simulium 1. small; 1-4 mm long 2. stout; short legs; thorax humped over the head (humped back appeatance) 3. short piercing proboscis; only females are bloodSpecies: Simulium indicum S. venustrum

sucking 4. broad wigs; not spotted; no scales; not hairy 5. holoptic eyes in male; dichoptic in female

S. baltazarae S. baisasae

S. philippinensis

Life cycle: Eggs laid on objects partly submerged in water in running streams  hatch into larvae in 4-12 days depending on temperature; larvae are carnivorous  develops into pupa after 6 molts  adults emerge after 5-6 days which are active early in the morning and in the morning and in early evening Life cycle of Blackfly

Importance: 1. causes painful bites and gives rise to vesicles and wart-like lesions 2. swarms cause animal to stampede 3. causes anemia in poultry in severe infestation 4. low milk and meat yield

5. serve as i.h. of Leucocytozoon anatis / simondi in ducks and L. smithi in turkeys as well as Haemoproteus nettionis in ducks and geese 6. serve as i.h. of filarial nematodes - Onchocerca 8

gutturosa - cattle, O. volvulus – man 7. inhalation of flies may cause

pneumonia foreign

body

Control: 1. medicated screen / clothing 2. spray with 0.5% lindane

3. apply 0-1-0.3 ppm DDT to streams in 2 cycles, each cycle lasting 10 days as larvicide

PSYCHODIIDAE (SANDFLIES, OWL MIDGES) Genus: Phlebotomus 1. 2. 3. 4.

small, slender flies, up to 1.5 mm long wing and body are hairy legs long long, slender, and hairy antennae; with 16 segments; often with beaded appearance 5. recurved palpi; hairy 6. piercing mouthparts; only females are blood sucking

7. nocturnal feeding habit •Note: Lewis classified these flies into 2 families: •Phlebotomidae (sandflies) - blood sucking •Psychodiidae (moth flies) - not blood sucking

Species: Phlebotomus philippinensis P. nicnic P. mangyanis P. lagunensis Life cycle: Eggs laid in batches of 40-60 in moist dark places between stones, loose soil, rock, crevices, etc.  larvae molt 4x  pupae  adult (entire life cycle takes 6 weeks) Importance: 1. P. papatasi, P. sergenti, and P. major serve as i.h. of a. Leishmania tropica cutaneous leishmaniasis b. Leishmania brazilensis - mucocutaneous leishmaniasis c. Leishmania donovanii visceral

leishmniasis or Kala-azar 2. P. mongolensis and P. verrucarum serve as transmitter of Bartonella bacilliformis, the causative organism of Carrion's disease (Oroya fever) 3. Transmit virus of 'sandfly fever' where a transmission is possible

Control: 1. removal of dense vegetation 2. spray walls with insecticides

3. treatment of breeding places

SUBORDER: BRACHYCERA TABANIDAE (HORSEFLIES OR BREEZE FLIES) Genera: Tabanus Chrysops

Pangonia Hybometra

General characteristics: 1. large robust flies with powerful wings and large eyes 2. eyes holoptic inmales, dichoptic in females 3. antenna with 2 short basal segments, the 3rd segment being large and usually ringed or annulated

Silvius Haematopota 4. proboscis is relatively short in Tabanus and Hematopota, longer in Chrysops and very long in Pangonia which projects forward 5. eyes are metallic in color 6. wings of Chrysops has a dark band and is divergent at rest; Hematopota has mottled wings; 9

Tabanus has a clear wing which is horizontal at Habits of Adults: 1. most active on hot sunny days 2. attack singly, chiefly large animals like cattle, carabaos, buffaloes, and horses 3. feeds mainly of the underside of the abdomen,

rest

around the navel, on the legs, neck, and withers 4. intermittent feeding habit (bite in a number of ties in different places or different animals before they are replete with blood)

Life cycle: Eggs laid in batches of 300-600 in stones or leaves overhanging body of water or marshy places  larva drops to the ground after about a week; larva is maggot-like, aquatic, and carnivorous larva undergoes 6 ecdyses for 2-3 months pupate in the drier ground for 2-3 weeks adult (cycle completed in 4-5 months) Life cycle of Horsefly

Pathogenic effects: 1. bites are painful and irritating that animals become restless 2. acts as mechanical carrier of diseases a. bacterial diseases - anthrax, tularemia b. viral diseases - equine infectious anemia c. protozoan disease: • surra caused by Trypanosoma evansi • mal de cadera caused by T. equinum

•

nagana or sleeping sickness caused by T.brucei and T. vivax • anaplasmosis caused by Anaplasma marginale et centrale 3. serve as i.h. of filarial nematodes a. Loa loa – Chrysops b. Elacophora schneideri - Hybometra and Tabanus 4. serve as i.h. of Trypanosoma theileri of cattle and carabaos

Control 1. use of fly trap or net 2. catching manually using animals as baits

3. spray with mixture of 1% pyrethrin and 10% piperonyl butoxide at the rate of 1 L/large animal

SUBORDER: CYCLORRHAPHA MUSCIDAE 10

Genera: Musca Fannia

Stomoxys Haematobia / Lyperosia

Musca domestica "common housefly" - human and animal houses and buildings Musca autumnalis "face fly" - nostrils and eyes of cattle and horse Musca sorbens - markets and houses M. conducens - animal houses Characters: 1. not blood-sucking, non-biting, indoor flies 2. 6-7 mm long 3. arista bilaterally plumose up to the tip, thorax 4. thorax and abdomen with stripes on the dorsum 5. mouthparts are lapping type; fleshy, expanded labella and covered by pseudotrachea adapted for imbibing liquid food Life Cycle: Eggs are laid in batches of 100-150 at a time (about 1,000 eggs) in animal manure or any fermenting or decaying organic matter eggs hatch in 20-24 hours larva persists for 4-8 days then pupate pupal stage lasts 4-5 days or longer young adult emerges from the puparium by means of the ptilinium fertilization and oviposition takes a few days after emergence of the fly from the puparium Note: It has been estimated that a pair of Musca can be a progenitor of 191,000,000,000,000,000,000 in 6 months with 100% survival

Habits of houseflies and their role in disease transmission: 1. adults feed on human food, blood and serum from meat, or from blood that oozes out from other insect bites, mucus, sputum, excretions from sores, wounds, etc 2. female deposit eggs on human and animal manure; they go back and forth between food and feces which is ideal for disease transmission 3. after a full meal, part of the ingested food is regurgirated back to the outside, this material is called "vomit drop" or "vomit spot" 4. fly specks or fecal deposits - houseflies also deposit feces or defecate on food 5. labella are fleshly and wrinkled, the presence of pseudotrache make them very efficient as disease transmitters 6. hairy legs, body, foot pads - efficient disease transmitter 7. M. autumnalis - commonly found around the nostrils and eyes of cattle, horses and other animals including man especially during summer Disease transmitted: 11

1. Mechanically transmitted a. Viral Cholera El tor Poliomyelitis b. Bacterial • Salmonella --- typhoid • Vibrio – dysentery • Bacillus anthracis – anthrax • Moraxella bovis - Infectious Bovine Keratitis (Pink eye) • Mycobacterium sp. – Tuberculosis c. Parasites 1. amebiosis – Entamoba histolytica 2. coccidiosis – Eimeria and Isospora 3. helminths – Ascaris, Trichuris, Enterobius 2. Serves as intermediate host of the ff: a. Raillietina sp b. Habronema muscae - equine stomach worm c. Thelazia rhodesii (cattle eye worm) - by Musca autumnalis Control 1. Larvae a. Destruction of breeding places • Spreading manure thinly on pasture • Spraying manure with larvicide like Borax powder over a heap of manure c. Inhibit larval development - Larvadex in feed d. Frequent removal of manure 2. adult a. mix molasses (sugar) with insecticides (diazinon, dieldrin, parathion, neguvon) and sawdust b. spray with insecticides (baygon, malathion, neguvon) c. backrubbers with either 2% malathion dust, dichlorvos, and 5% metoxychlor d. insecticidal dust bags 3. proper garbage disposal 4. efficient sewage disposal 5. screening of houses Relatives of houseflies 1. Fannia canicularis - lesser housefly 2. Fannia scalaris "little housefly" - may cause "urogenital myiasis"; smaller than Musca; larvae with feathered protuberances; arista is bare 3. Muscina stabulans - may cause "intestinal myiasis"; larger and more robust than the housefly; common in stables 4. Morrelia hortorum "sweat fly" - adults attracted to sweat and mucus Stomoxys calcitrans "stablefly" 1. proboscis is sucking type, directed horizontally forward 2. arista plumose only dorsally 3. thorax has 4 longitudinal stripes of which the 2 lateral are broken 4. the abdominal segment which is shorter and broader is provided with 3 dark spots 5. outdoor flies and both male and female are blood sucker Life cycle: Female lays 25-50 eggs at a time (total of 800) in decaying vegetable matter after at least 3 blood meals 1eggs hatch in 3 days larval stage lasts for 12 days pupate on drier ground for 6-9 days oviposition begins 9 days after emergence Life cycle completes in 30 days; life span is about 72 days

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The Life Of Stomoxys Calcitrans Pathogenic effects: 1. cause annoyance 2. serves as mechanical transmitter of : a. protozoa • T. evansi • T. equinum • T. brucei • T. vivax • T. gambiense • T. rhodesiense b. Bacteria • B. anthracis • Hemorrhagic septicemia (P. multocida) • Equine infectious anemia 3. Serve as i.h. of equine stomach worm (Habronema spp) Control: 1. 2. 3. 4.

frequent removal of manure and fermenting materials spray manure thinly on the pasture spray animal houses and animal with insecticides like DDT in kerosene backrubbers

Hematobia (Lyperosia or Siphona) Hematobia exigua - buffalo fly H. irritans - hornfly 13

1. 2. 3. 4. 5. 6. 7.

smaller than S. calcitrans; about 4 mm in length male and female are blood suckers palpi as long as proboscis thorax with 2 dark stripes hovers around face and body of carabaos, cattle, and buffalo rarely leave the host except for a brief flight when disturbed infestation reaches 1000-4000/animal to as high as 10,000 to 20,000/animal

Life cycle: Eggs laid in fresh Carabao or cattle manure hatch in 24 hours larval stage lasts for 4 days pupate for 5-10 days adult

Life cycle of Hornfly Effects on the hosts: 1. interferes during grazing periods 2. animal develop sores and wounds resulting to myiasis 3. fly specking - animals constantly shake their head to drive away flies 4. cause blood loss, low milk and meat yield by 10-20% 5. transmits mechanically surra, anthrax, hemorrhiagic septicemia. 6. serve as i.h. of Habronema sp and Stephanofilaria stilesi Control: 1. backrubbers impregnated with 5% rotenone, 5% methoxychlor dust, 2% malathion dust 14

2. regular insect spray GLOSSINIDAE (TSETSE FLIES) Glossina morsitans G. palpalis, G. longipalpalis, G. brevipalpalis G. tachinoides 1. 2. 3. 4. 5.

larger than the houseflies, narrow-bodied, yellowish to dark brown common in Africa both sexes are blood suckers arista bears dorsal branching hairs proboscis is held horizontally and ensheathed in long palpi which is as long as the proboscis

Life cycle Larviparous female lays on fully-grown larva at a time pupates upon liberation in sandy soil with humus around tree trunk, crack or crevices under shaded areas pupal period is 35 days Note: Gestation period is 10 days; one female may produce 8-10 larvae; one act of mating renders a female fertile for life; the larvae within the uterus is attached to a "teat" from which "milk is obtained Habits: 1. adult flies subsist on blood of warm blooded animals 2. fly feeds every 3 days; active in forenoon and afternoon; some spp. Are noctural (G. brevipalpalis) 3. rest on shady places Effects on the host 1. serve as i.h. of Trypanosoma brucei, T. congolense, and T, vivax which cause "Nagana" in animals and T. gambiense and T. rhodesiense which cause "sleeping sickness" in man Control: 1. Previous strategies • Large scale killing of game animals which are reservoir hosts • Clearing large areas of bush to destroy the fly habitat 2. Current strategies • Insecticides sprayed from the ground or by aircraft • Non-residual or residual insecticide • Trapping - use of dark cloth impregnated with insecticide • Catching with hand nets • Fly screens • Biological control - release of sterile males MYIASIS FLIES Myiasis flies - dipterous insects whose larvae invade tissues or organs of man and animals causing a condition known as myiasis. The adults do not suck blood Myiasis may be grouped according to their ovispositioning and larvipositioning habits: 1. Accidental myiasis - eggs or larvae are deposited in manure or decaying organic matter, garbage, carcasses, and myiasis is usually acquired accidentally by ingestion of eggs or larvae with contaminated feed or water. Eggs may be deposited around the anus or vulva and larvae, and upon hatching, migrate to the rectum or intestine and vagina respectively. Species Involved Blue Bottle Flies - Calliphora sp. Green Bottle Flies - Lucilia sp. Fleshflies - Sarcophaga sp. Houseflies sp. - Musca sp 15

2. Specific or obligate myiasis - eggs or larvae are deposited in or near living tissues / organs and larvae inevitably become parasitic a. Screw worm flies • Callitroga sp • Chrysomyia sp. b. Bot flies • Gasterophilus sp c. Warble flies • Hypoderma sp 3. Semi-obligate myiasis - eggs and larvae are deposited in decaying organic matter and less frequently in diseased tissues and neglected wounds a. Flesh flies - Sarcophaga sp b. Green Bottle Flies - Lucilia sp c. Blue Bottle Flies - Calliphora sp d. Black Bottle Flies - Phormia sp Myiasis may also be classified according to organ affected: •Cutaneous - skin •Ocular - eyes •Aural - ears •Gastric - stomach •Intestinal - intestine •Vaginal, nasal, scrotal, rectal, etc. Myiasis belong to four important families: Calliphoridae Sacrophagidae Oestridae Cuterebridae

Identification key for agents of wound myiasis:

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CALLIPHORIDAE Genera: •Calliphora - blue bottle flies •Lucilia - green bottle flies / copper bottle flies •Phormia - black blow fly 17

•Chrysomyia - screw worm fly •Callitroga - screw worm fly •Cordylobia - skin maggot fly •Booponus - foot maggot fly Calliphora vomitoria C. erythrocephala •Stout with metallic blue color •Measures about 12 mm; with red eyes •Squama with short and long hairs Lucilia cuprina / Caesar - affects sheep in Australia L. sericata - affects sheep in the US •Stout flies with metallic coppery green •Squama with short hairs only •Eyes are brownish red •Measures about 8-10 mm Phormia regina P. terrae-novae •Black with metallic blue-green sheen Note: maggots of these 3 genera produce 'blowfly strike' in sheep Life cycle of calliphorine flies in general: eggs are laid in cluster in batches of 50-150 (around 3,000-5,000 eggs are laid in a lifetime) eggs hatch in 8 hrs to 3 days giving rise to larvae which are segmented, wormlike, mobile, and apodous larvae molt twice and becomes a fully-grown maggot in 2-19 days prepupal period of 2-7 days mature larvae leave the host or carcass to pupate on the ground pupa persist for 3-7 days adult Life cycle is complete in 2-5 weeks Life span of adult - 1 month or longer; 9-10 generation may be completed in a year Pathogenesis: 1. wounds on the skin attract blowflies 2. eggs are laid on the wool 3. larvae form deep tunnels in tissues; maggots secrete proteolytic enzymes which digest and liquefy tissues of the host then feed on them 4. foul smell attracts other flies to lay their eggs 5. larval movements cause irritation; animal does not feed properly resulting in emaciation and weakness and consequent reduction in meat and milk yield 6. burrowing of larvae into the skin may be complicated by secondary bacterial infection 7. animals may die of toxemia or septicemia 8. the value of the fleece becomes reduced Treatment 1. clip wool and surgically remove the larvae 2. use of low concentration dressing compounds 3. dip or spray with insecticides Callitroga hominivorax - primary screw worm fly C. macellaria - secondary screw worm fly •bluish green color with 3 longitudinal stripes on thorax •eggs are laid at the edge of the wound or on the carcass •adult is formed after 3-7 days Effects on the host: Rainy weather predisposes the animal to screw worm infection; they penetrate into the tissues, which they liquefy 18

and extend the lesions considerably. The effect on the animal is more on the production aspect, as the animal becomes weak and restless. Treatment: 1. thorough cleaning of wounds and dressing it with appropriate antiseptics 2. destroy larvae Chryzomyia bezziania - "bluish green fly" •most important myiasis fly in the Philippines particularly in Negros and Panay islands •maggots of Callitroga and Chryzomia are known as screw worms •attack man and animals Life cycle: Eggs laid in clusters of 150-300 at the edges of wound or sore  eggs hatch in 10-12 hours and mature in 3-6 days drops to the ground and pupate for 3-7 days but may reach up to 2 months adult Pathogenic effects: 1. 2. 3. 4.

maggots penetrate and liquefy tissues lesions attract more flies severe cases may cause death myiasis of the navel may lead to peritonitis, septicemia, and death

Treatment: 1. 2. 3. 4.

dress wound with 0.3% dieldrin or 0.5% BHC dipping or spraying with 5.0% coumaphos, 0.25% diazinon 3% of lindane in gel base Myiasis smear / paste #1 •chloroform - 40 ml (larvicidal) •tincture of iodine - 25 ml (stimulate tissue growth) •pine tar - 28 ml (fly repellent) •charcoal powder enough to make a pasty consistency (gives thickness to smear) Apply two times a week Myiasis paste #2 •Charcoal powder - 95 parts •Coumaphos powder - 5 parts •Pine tar - q.s. [aste

Cordylobia anthropophaga - tumbu fly or skin maggot fly •Occurs in tropical Africa •Measures 9.5 mm and light brown in color Life cycle: Eggs laid on sleeping places of man and other animals with perspiration odor larvae produced after 2-4 days  penetrate intact skin and produce painful swellings pupa is produced after 8-15 days adult develops after 3-4 weeks Pathogenic effects: The larva is situated ion a swelling which is about 1 cm in diameter, painful, and has a small, central opening. Treatment: Press out larva and apply a disinfectant Booponus intonsus - foot maggot fly •The same size as the housefly but light yellow in color •Common during the dry season in Laguna, Quezon, Leyte, and Mindanao 19

•Attack ruminants Life cycle: Eggs are laid on the hairs along the coronet and the posterior part of the hoof eggs hatch into larvae in 3-5 days then penetrate and produce wounds pupa is produced after 2-3 weeks adult develops 10-12 days Pathogenic effects 1. lameness due to pain in the foot parts 2. secondary bacterial infection (Bacteriodes nodusus) particularly Foot rot complicates the condition Treatment: 1. apply grease mixed with 0.3% dieldrin/diazinon 2. soak large piece of cotton in chloroform or kerosene and pack affected foot; remove maggots with forceps then paint with pine tar or myiasis paste SARCOPHAGIDAE (FLESH FLIES) Sarcophaga hemorrhoidalis S. fusicauda •light or dark grey in color •thorax with 3 longitudinal stripes •abdomen with dark checkered markings •larviparous Life cycle: Larvae deposited in fresh or decomposing meat, wound, sores, and abscesses; larva becomes a pupa in 6 days à the pupa transforms into imago after 12-24 days Wohlfartia magnifica - deposit larva in cutaneous lesions or sores, nasal, and aural cavities, eyes and vagina Wohlfartia vigil - deposit larvae on intact skin GASTEROPHILIDAE (HORSE BOT FLIES) Criteria Reference of the Different Gasterophilus sp. Site of egg Routes of larval deposition penetration Gasterophilus Hairs all over the body Tongue mucosa intestinalis preferably on forelegs, around fetlock, and underside of knees Gasterophilus nasalis Hairs in the Mucosa between intermandibular space molar teeth (throat) G. hemorrhoidalis Hairs of lips and Tongue mucosa cheeks G. pecorum Hooves and inanimate Cheek mucosa objects G. inermis Hairs of lips and Cheek mucosa cheeks

Larval predilection site Cardiac portion of stomach Pylorum an duodenum Stomach and rectum Stomach and rectum Pharynx, esophagus, and stomach

Life cycle: Eggs hatch after 5-10 days (eggs of G. intestinalis and G. pecorum have to be licked or rubbed by the host to hatch while others hatch spontaneously larva migrate in the mouth mucosa and wander as far as the pharynx for 3-4 weeks fully grown larvae pass down the stomach and lodge in predilection sites larvae remain in the host for 10-12 months detach and pass out in the feces to pupate in the ground (those of G. hemorrhoidales and G. pecorum reattach for a few days in the rectum before leaving the host) pupal period lasts for 3-5 weeks before the adult is formed Pathogenesis: 1. oviposition pattern cause annoyance 20

2. stomatitis with tongue ulceration 3. cluster of maggots around pylorus mechanically interfere with action of sphincter and food passage 4. spines of the larvae may cause ulceration in the stomach which may be dramatic in appearance but have obscure pathogenic significance 5. abscess formation, rupture of stomach, peritonitis 6. accidental larval infection in man is limited to skin "creeping eruptions" Diagnosis: 1. Examination of sites at which eggs are deposited 2. direct inspection of the pharynx may reveal the larvae 3. larva in the stomach and rectum may be seen at necropsy Treatment: 1. piperazine and carbon disulfide complex - 20-40 grams/500 lbs via stomach tube 2. dichlorvos - 14-15 mg/lb given in feed 3. neguvon - 40mg/kg/wt (98& trichlorfon) OESTRIDAE Genera: Oestrus Hypoderma Rhinoestrus Oestrus ovis 'sheep nasal fly' 'nasal bots' 'sheep Nose fly' 'head maggot fly' Lifecycle: Female infect sheep by squirting a jet of fluid with larvae during flight (up to 25 at a time/ 60 in an hour)→larvae are deposited in nasal cavites and adjacent sinuses, sometimes in the eyes, nostrils, and lips of man→ larvae migrate to nasal passages feeding on mucus whose secretion is stimulated by their movements (L1-L2)→frontal sinus (L3)→lavae may die and calcify in this sites or larvae mature in 8-10 months then crawl out and drop to the ground to pupate →adult emerges after 3-6 weeks Pathogenic effects: 1. larviposition causes annoyance which may cause the animal to panic, stamp their feet, bunch together and press their bodies together against the ground; this interruptions may cause decrease in the production. 2. larvae irritate the mucosa which may cause viscid mucus nasal discharge, sneezing and rubbing of nose to fixed objects. 3. causes “false gid” – the bones of the skull may erode and cause injury to the brain producing nervous signs such as high stepping gait, incoordination and paralysis. Treatment: 1. induce sneezing by sprinkling snuff and pepper into the nostrils 2. administer 10 parts neguvon and 1 part coumaphos per os 3. apply 3% cresol-soap solution to the nostrils 4. trephination – create an opening to the skull Hypoderma - “warble flies” ”ox bot flies” ”heel flies” Hypoderma bovis “northern cattle grub” – affects cattle; most important species H. lineatum “common cattle grub” – affects cattle H. ageratum – sheep and goats (India) H. crossi – sheep and goats H. diana – deer (Europe) - adults are hairy; 13-15cm long - light yellow color as honey bees - mouthparts are redumentary and do not feed - most active during sunny days - adults live for an average of 1 week - female may lay 400-600 eggs in the course of her life Life cycle: Eggs are laid singly at hairs above the hock (H. bovis) or in rows of 6 or more at hairs below the hock (H. 21

Lineatum); 100 or more eggs are laid in a week→eggs hatch and larvae crawl down the hair and penetrate hair follicle→ migrate towards the diaphragm via the SQ tissue up the leg (L1) aided by mouth hooks and secreted proteolytic enzymes→ submucosa of esophagus (H. lineatum) or epidural fat of spinal canal (H. bovis) – L2 for 2 to 5 months→ reaches the SQ tissue of the back (L3) and form swellings (warbles) that measures 3cm→ L3 creates a perforation and apply their spiracles to the aperture for breathing purposes→larvae molt twice and mature in 30 days then fall to the ground to pupate(4-5weeks) →adult The complete life cycle takes about 1 year Pathogenic effects: 1. economic losses due to fly attack a. “Gadding” – animals panic when attacked by buzzing flies especially H. bovis that lay its egg singly therefore has to repeatedly attack the animal. The animal tends to run away aimlessly and injure themselves on fences or may die when they fall off in water over heights b. interrupted feeding – low milk and meat yield 2. downgrading and condemnation of hides 3. carcass depreciation – the flesh under the skin infested with L3 may be damaged producing the characteristic greenish gelatinous tissue which has to be trimmed “Butcher Jelly” 4. if the larvae dies in the spinal cord, the highly toxic proteolytic enzymes may cause paraplegia in the esophageal wall, it may cause bloat due to esophageal stricture 5. aberrant migration due to other organs may cause anaphylactic reactions or signs relative to the organ 6. escape of the larvae leaves an open wound which attracts myiasis flies. Clinical signs: 1. usually, there is no appreciable manifestation until the larvae appear along the back when the swelling can be felt and seen; larvae lies in a cyst containing yellow purulent fluid 2. poor growth is observed in severe cases 3. decreased milk yield Treatment: 1. Removal of larvae (mechanical) – ineffective when larvae are immature because its rupture may lead to inflammation, abscess formation or anaphylaxis 2. application of larvicide – organophosphate compounds and ivermectin Rhinoestrus purpurensis “gadfly” - larvae satges are obligatory parasites of the nasal sinuses and larynx of horses - cause opthalmomyiasis of man CUTEREBRIDAE Genera: Cuterebra Dermatobia Cuterebra emasculator “rodent bot fly” - occurs under the ski of rodents, rabbits, dogs, cats and man - present in north America Life cycle: Eggs are deposited I burrows of rodents; each females lays 2000 eggs→ eggs hatch and wait for host→ penetrate skin of nose and mouth and migrate to various SQ locations (frequently parasitizes the scrotum destroying the testes (parasitic castration)→ larvae mature in 30 days the pupate on the ground. Dermatobia hominis “human bot fly” “tropical warble fly”  adult flies do not feed - occurs in central and north America - man are infected by association with domestic animals 22

Life cycle: Adult females rest on leaves, captures a mosquito or other blood sucking fly→ glues a batch of eggs to the abdomen of the capive fly in 7 days (L1 develops within the egss)→ eggs hatch when insect land on warm-blooded animal when the latter sucks blood→ larvae penetrate skin using the skin puncture made by insect and migrate to the SQ tissue (larvae grows and produce a swelling under the skin)→ pupate on the ground→adults develops after 5-10 weeks Pathogenic effects: 1. cause “Uva” swellings in the various body parts which may suppurate and cause severe pain 2. attracts myiasis flies Treatment: 1. surgical or mechanical removal 2. ivermectin or topical trichlorfon HIPPOBOSCIDAE (LOUSEFLIES OR KEDS) General characteristics:  Pupiparous (female may lay larvae ready to pupate)  Pupa is roughly rounded and smooth like a brownish bean seed  With strong claws by means of which the parasite clings to the hairs or feathers of the host  With piercing blood sucking mouthparts in both sexes  Maybe permanent parasites Genera: Hippobosca “forest flies” Pseudolynchia Lepopthena Melophagus Hippobosca equina “horse lousefly” “horse ked” – attacks horse and cattle world wide H. rufipes – attacks cattle and hoses in Africa H. maculala – attacks cattle and horse in tropics and subtropics o adults are 10 cm in length and pale reddish brown in color o with yellow spots or bands  wings extend beyond the margin of the abdomen  proboscis are retracted when not feeding Life cycle: Female lays 1 larva at a time (max. Of 5-6) in dry soil or humus→ pupates almost immediately and change its color from yellow to black → pupal period may be a month or longer Habits: 1. adult flies are more frequent in warm weather 2. preferably bites on the hind legs and pubis but may bite another body parts 3. they are strong fliers but could not travel long distances 4. remains on the host for long periods and are not easily disturbed; when disturbed, they move sideways like a crab Pathogenic effects: 1. annoyance to animals which are not accustomed to attack 2. transmits Trypanosoma theilieri of cattle/carabaos and Haemoproteus of anatids and birds 3. mechanical transmitter of B. anthracis Control: 1. topical application of insecticides with repellant and residual effects (pyrethrin) Pseudolynchia maura/cauariensis “pigeon lousefly or pigeon fly” o attacks pigeons and wild birds in the tropics 23

o o o o

resembles sheep ked but have wings; dark brown in color well-developed wings which extent beyond the tip of abdomen wing venation reduced and concentrated anteriorly female produces 4-5 young during life

Life cycle: Larvae are laid in dark crevices of pigeon houses, in dry dust or nests (a female produces 4-5 larvae in an lifetime of around 43 days → pupates in a few hours after deposition which lasts for 23-30 days in warm weather→ adult (copulation takes place on the host) Habits: 1. moves rapidly through feathers 2. fast fliers; not easily caught and handled Pathogenic Effects: 1. serve as i.h of haemoproteus columbae “pigeon malaria” 2. suck blood and cause painful wounds in 2-3 weeks squabs 3. cause anemia in young pigeons Control: 1. dust birds with 5% pyrethrum powder, 5% rotenone powder 2. regular or thorough cleaning of pigeon loft Lepopthena cervi “deer ked” o both sexes are winged but when the female found a host, the wings breaks off and resemble Melophagus ovinus Melophagus ovinus “sheep ked” o wingless with strong legs and stout claws o with brown hairy body o more common in temperate countries o longetivity of males – 90 days; females - 120 days Life Cycle: Female attaches its single immobile larva (max. of 10-20 larvae) to the wool by means of a sticky substance→pupates within 12 hrs into a chestnut brown pupa (pupal period is 20-45 days) → adult → copulation begins after 3-4 days (gestation period is 10-12 days) Habits: 1. permanent ectoparasite 2. enorged female may live up to 8days off the host 3. pupae removed from the sheep could still “hatch” if the temperature is favorable but will die soon if they could not find a sheep to feed on Pathogenic significance: 1. anemia 2. wool damage – severe irritation will cause the animal to bite, rub, or scratch itself; ked’s feces stain the wool which don’t wash out readily 3. transmits Trypanosoma melophagium which is actually non-pathogenic 4. heavy infestation causes emaciation, unthriftiness, loss of condition, and anemia 5. predisposes the sheep to “blowfly strike” Control: 1. shearing to remove pupa and adults 2. dipping, spraying or dusting with dieldrin, aldrin, coumaphos, chlordane etc. ORDER HEMIPTERA (Bugs) General characteristics: 24

1. 2. 3. 4.

body flattened dorsoventrally jointed proboscis and flexed under the head when not in use blood suckers wing may or may not be present

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