An adult Haematopinus suis is the largest of the sucking lice, order Anoplura, measuring a little over 0.5 centimeters from the tip of the head to the end of the abdomen. At the very anterior part of the head are short antennae with three segments and modified mouthparts. The Anoplura are distinguished as the 'sucking lice', because of their modified stylets for sucking up a blood meal, as opposed to the more primitive order known as the 'chewing lice' (Mallophaga). Haematopinus suis mouthparts are contained in a structure known as the labrum, which bear teeth at its apex. Within the labrum is a structure known as the haustellum, which supports the four retractable stylets (the fascicle). The fascicle moves into host tissue during feeding and retracts back into head at the end of the meal. Two stylets, supported by a structure within the labrum known as the maxilla, lock together and form the food channel. One stylet just anterior to the food channel, derived from a structure known as the hypopharanx, connects the salivary gland to the locale of feeding. The other stylet, derived from the labium, the anterior most end of the mouth parts, is flattened with a serrated tip, which guides the other stylets. Haematopinus suis exhibits a loss of maxillary palps found on other lice.
The thorax section of H. suis is reduced and primarily functional for locomotion. There are three appendages on each side. Each appendage is segmented; the last segment has terminal claws for grasping on to swine hair. The abdomen of H. suis has spiracles for respiratory gas exchange as well as sex organs for reproduction.
Male H. suis are slightly smaller than females and are characterized by the presence of an aedeagus or sperm transferring organ.
Average length: 0.5 cm.
Sexual Dimorphism: female larger
Other Physical Features: ectothermic ; bilateral symmetry
Symptoms of H. suis infection in domesticated swine include itching with the feet and/or against objects or each other, blue skin, skin lesions, and decreased weight and food intake. Large numbers of H. suis can often be seen in the ear, neck, and tail regions of the hog.
Control measures include bio-security (quarantine) and chemical pesticide treatment. Whenever new swine are brought to the herd, they are separated from the others and monitored for H. suis infection. Chemical pesticide treatments are used in hay bedding for infection prevention as well as treatments on the skin for infected herds. The common pesticide treatments today are amitraz, coumaphos, and fenthion.
The sensory organs found on the head of H. suis include two simple eyes (not compound) and short antennae with chemoreceptors and tactile receptors. It is believed that, when feeding, lice know they have found a blood vessel by stylet chemoreception of nucleotide bases, notably ADP and ATP, which are anti-coagulation factors found in high concentrations around penetrated blood vessels.
It is not known how these lice communicate with one another.
Perception Channels: visual ; tactile ; chemical
Haematopinus suis is not an endangered species. In fact, great measures are taken to eradicate H. suis in domesticated swine, due to the harm it causes its host population, and the economic impact on human consumption.
Haematopinus suis is hemimetabolous, meaning it has a gradual metamorphosis, rather than a complete metamorphosis as in holometabolous insects. Haematopinus suis metamorphosis consists of 3 nymphal instars, all permanent parasites. From hatching out from the egg, it takes young lice about 10 days to complete the three nymphal instars and become adults. After the 10th day, mating begins.
Development - Life Cycle: metamorphosis
It is estimated that economic losses from H. suis suffered by farmers in the United States range anywhere from 10 to 50 million dollars annually. This is a huge problem for hog farmers. Haematopinus suis infestation is not usually lethal to the swine population, but economic losses are attributed to decreased swine growth due to a decrease in food intake, skin irritation, and immune response to the parasite. In very young or sick pigs, death can occur from louse infection due to anemia. Furthermore, H. suis has been implicated as a vector of many swine diseases, such as swine pox virus, Eperythrozoon suis, and hog cholera, with lethal consequences. One reason H. suis is of such economic concern is because of its dispersal. Females lay large quantities of eggs, and movement from one hog to another is rapid in a stable (manger) environment. One infected hog can infect the entire stock in a matter of days.
Negative Impacts: causes or carries domestic animal disease
The ecological interactions of Haematopinus suis fall under the realm of parasitism, where one organism (the parasite) benefits to the detriment of another (the host). Haematopinus suis is an obligate ectoparasite of swine. It is also a vector (a mechanism which transports a parasite, often a disease causing parasite) of many lethal swine diseases.
Ecosystem Impact: parasite
Species Used as Host:
Haematopinus suis feeds exclusively on the blood of the host and is termed solenophage because its mouthparts burrow into a blood vessel for feeding. Haematopinus suis demonstrates complete host specificity; i.e. its host is always swine. The modified mouthparts of Haematopinus suis cut into the hog's skin where the stylets move into a blood vessel and extract blood. The teeth of the labrum cut the skin and hence anchor the louse in place, the stylets move into tissue while secreting salivary material to breakdown tissue and inhibit coagulation, and find a blood vessel (usually a venule). Once penetration has occurred, the blood is sucked up the food channel by a pump mechanism in the louse's head, and enters the digestive tract, where enzymes hemolyze erythrocytes, keeping the blood in a liquid form, which may inhibit prokaryotic disease transmission.
Animal Foods: blood
Primary Diet: carnivore (Sanguivore )
Haematopinus suis is found in all places in the world where domesticated and wild hogs live. It is commonly found on livestock swine in the United States.
Other Geographic Terms: cosmopolitan
Haematopinus suis lives on the surface of swine. It grips the hair with its claws, and moves through the pelage in a side-to-side fashion. Young nymphs spend much of their time in the ear of the host, and as they mature, move to other body regions for feeding, eventually finding the host's abdominal region. Haematopinus suis lives in all areas where swine are found and can survive in extremely cold conditions often associated with domesticated swine.
Other Habitat Features: agricultural
Haematopinus suis is a permanent parasite; it spends its entire life cycle on the swine host. In fact, if it becomes dislodged from the host, it only lives an average of 2 or 3 days, remarkably less than the average 35 day lifespan in association with the host.
Average lifespan
Status: wild: 35 days.
No information is available on the mating system of these lice.
After mating the female lays eggs called nits on the hog's hair close to the skin. She lays 3 to 6 nits a day for about 25 days, an average of about 90 nits per lifetime. The nits have opercula, small holes for gas exchange. Most eggs hatch in 12 to 14 days, but it can take up to 20 depending on temperature conditions. These lice become sexually mature about 10 days after hatching.
Breeding interval: Females lay 3 to 6 eggs per day, for 25 days.
Breeding season: These lice can breed year round, but are most active in winter.
Average eggs per season: 90.
Average age at sexual or reproductive maturity (female): 10 days.
Average age at sexual or reproductive maturity (male): 10 days.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Female lice provide nutrients to their eggs before laying them, and abandon them afterwards.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female)
Swiniô pùrchwa (Haematopinus suis) - to je ôrt òwada z rodzëznë Haematopinidae. Z tima pùrchwama béł skweres m. jin. na Kaszëbsczim Pòjezerzu. Domôcô swinia czasã miéwô je na chrzepce. To je cëzożiwca.
Swiniô pùrchwa (Haematopinus suis) - to je ôrt òwada z rodzëznë Haematopinidae. Z tima pùrchwama béł skweres m. jin. na Kaszëbsczim Pòjezerzu. Domôcô swinia czasã miéwô je na chrzepce. To je cëzożiwca.
Haematopinus suis, the hog louse, is one of the largest members of the louse suborder Anoplura, which consists of sucking lice that commonly afflict a number of mammals. H. suis is found almost solely on the skin surface of swine, and takes several blood meals a day from its host.[1] H. suis has large claws that enable it to grasp a hog's hair and move around its body. It is easily seen without magnification, being 5–6 millimetres (0.20–0.24 in) long. H. suis has a long, narrow head and long mouthparts adapted for sucking blood. It is the only louse found on swine.[2] H. suis infestation is relatively rare in the US; a 2004 study found that about 14% of German swine farms had H. suis infestations.[3] Due to the frequency of feeding, infected swine become severely irritated, often rubbing themselves to the point of injuring their skin and displacing body hair. Particularly afflicted hogs may become almost completely bald and, in young hogs, the resulting stress can arrest growth, a cause of concern for farmers.[4]
Haematopinus suis have relatively narrow heads with pointed fronts. The mouthparts of H. suis are contained in the labrum, with teeth at the tip. Within the labrum are four thin, retractable, perforating stylets (the fascicle) used for capillary sucking in the front.[1][5][6] Of the stylets that compose the fascicle, two form the food channel, supported by the maxilla. Of the remaining two, one connects the salivary gland to the feeding site, and the other guides the other stylets and is flattened with a serrated tip.[1][5] The heads have long lateral antennae.[6] A defining feature of H. suis is the lack of maxillary palps typically found on other lice[1][5]
The thorax of H. suis is primarily for movement. The three pairs of legs are attached at the thorax. Each leg has large claws for grasping the hair of the host.[1][5]
The abdomen of H. suis is black when blood-filled, wider than the thorax, and contains lateral spiracles for respiration.[6] A defining characteristic of H. suis is the paratergal plates lining the sides of each segment of the abdomen. These plates almost completely line the abdomen, and are much larger and more prominent than those of other species of lice.[7]
Female H. suis are larger than their male counterparts. Males also contain an aedeagus, a sperm-transferring organ.[6]
Like many insects, H. suis is oviparous and iteroparous, meaning that development of the offspring occurs outside the mother's body (oviparous) and are produced in more than one group across multiple seasons (iteroparous).[7] Female H. suis lay 3–6 eggs per day following a blood meal and mating, eventually laying about 90 eggs. The amber eggs are deposited on the lower half of the swine's side, or the neck, shoulders, flanks, or on the back of the ears. Lice eggs are commonly referred to as "nits".[Note 1] These nits have small holes for gas exchange, called opercula. Typically, eggs will hatch within 12–14 days, but this varies depending on temperature.[4]
The hog louse spends its entire life cycle on its host. The life cycle is completed in about 5 weeks.[8] H. suis are hemimetabolous (gradual metamorphosis). The metamorphosis of hog lice includes 3 nymphal instars.[7] Once hatched, young lice molt and move to tender areas of the body to feed. Nymphs tend to remain concentrated near the head region. After 10 days, the lice are sexually mature and ready to begin another life cycle.[4]
Haematopinus suis is a permanent parasite, meaning it spends its entire life cycle on the swine host. If a hog louse is ever removed from its host, the louse typically survives for only 2–3 days. If a louse remains on its host however, it will survive an average of 35 days.[7]
Haematopinus suis feeds only on its host swine's blood. It is classified as a solenophage, because its mouthparts burrow directly into a blood vessel to feed. The mouthparts of the hog louse cut into the hog's skin, and the stylet is then introduced into a blood vessel and begins to extract blood. The teeth of the labrum are used to cut the skin and anchor the louse to the hog, and the stylets move into the tissue, all while secreting saliva that acts as an anticoagulant. Once penetrated, the blood is sucked up the food channel by a mechanism located in the louse's head. The blood enters the digestive tract, where enzymes hemolyse erythrocytes (the blood is essentially disintegrated to keep it in liquid form); the hemolysation may also serve to inhibit disease transmission (i.e. bacterial infection).[5]
Nymphal H. suis spend most of their time in and around the head region of the hog, specifically the ears. As they mature, they move to other areas on the host's body, primarily the abdominal region.[1]
Because it is a permanent parasite, the hog louse will only leave its host to move to another host, always swine. The most common migration of lice between hogs is via direct contact (i.e. sexual contact or close proximity). Lice can however, survive off-host for short periods of time, such as in pigs' bedding.[3] Lice eggs are often found in hay and troughs.[7]
Infestations of H. suis are not usually lethal to the hosts, but major economic losses are ascribed to impaired growth, general irritation, and immune responses to the lice. Estimated economic losses due to hog lice infections are from 10 to 50 million dollars a year.[1] H. suis is the vector of swine pox in hogs.[8] It also transmits hog cholera, considered the most important health concern for swine, hog lice being the second.[1][7][8]
Because the louse have neither free-living stages nor vectors for infection of H. suis, control is difficult when using insecticides and quarantines.[4] Sows can be treated with avermectin, a common therapy treating arthropods and nematodes, prior to farrowing to keep lice from moving to younger hogs.[8] Pesticides such as amitraz, coumaphos, and fenthion can be used in hay bedding for prevention.[1][7]
Haematopinus suis, the hog louse, is one of the largest members of the louse suborder Anoplura, which consists of sucking lice that commonly afflict a number of mammals. H. suis is found almost solely on the skin surface of swine, and takes several blood meals a day from its host. H. suis has large claws that enable it to grasp a hog's hair and move around its body. It is easily seen without magnification, being 5–6 millimetres (0.20–0.24 in) long. H. suis has a long, narrow head and long mouthparts adapted for sucking blood. It is the only louse found on swine. H. suis infestation is relatively rare in the US; a 2004 study found that about 14% of German swine farms had H. suis infestations. Due to the frequency of feeding, infected swine become severely irritated, often rubbing themselves to the point of injuring their skin and displacing body hair. Particularly afflicted hogs may become almost completely bald and, in young hogs, the resulting stress can arrest growth, a cause of concern for farmers.
Seatäi (Haematopinus suis) on täiliste seltsi kuuluv putukaliik.
Putukat on ka Eestis.[1]
Seatäi (Haematopinus suis) on täiliste seltsi kuuluv putukaliik.
Putukat on ka Eestis.
Wesz świńska (Haematopinus suis) – gatunek wszy należący do rodziny Haematopinidae, pasożytujący na świni (Sus scrofa f. domestica). Powoduje chorobę wszawicę.
Samiec długości 4,2 mm, samica 5,0 mm[1], największa wesz zwierząt domowych w Europie i jedna z największych znanych. Według innych samice wszy świńskie osiągają rozmiary w zakresie od około 4,5 mm do prawie 6,0 mm, samce zaś 3,5 mm do 4,75 mm[2]. Są silnie spłaszczona grzbietowo-brzusznie. Głowa dwukrotnie lub trzykrotnie dłuższa jak szersza. Nogi bardzo duże i silne. Samica składa 3 do 6 jaj dziennie przez około 25 dni. Średnio składa około 90 jaj zwanych gnidami, barwy żółtawobiałej z wieczkiem na górnym biegunie. Wielkości 1,0 - 1,5 mm[3] długości. Są one mocowane specjalnym "cementem" u nasady włosa. Po około 12-14 dniach z jaj klują się młode wszy. Rozwój osobniczy trwa po wykluciu się z jaja około 14 dni. Długość życia wszy świńskiej wynosi około 35 dni. Pasożytuje na skórze owłosionej głównie w okolicy nasady uszu, na karku, na bokach ciała. W przypadku silnego opadnięcia może występować na całym ciele. Kosmopolityczny.
Wesz świńska (Haematopinus suis) – gatunek wszy należący do rodziny Haematopinidae, pasożytujący na świni (Sus scrofa f. domestica). Powoduje chorobę wszawicę.
Samiec długości 4,2 mm, samica 5,0 mm, największa wesz zwierząt domowych w Europie i jedna z największych znanych. Według innych samice wszy świńskie osiągają rozmiary w zakresie od około 4,5 mm do prawie 6,0 mm, samce zaś 3,5 mm do 4,75 mm. Są silnie spłaszczona grzbietowo-brzusznie. Głowa dwukrotnie lub trzykrotnie dłuższa jak szersza. Nogi bardzo duże i silne. Samica składa 3 do 6 jaj dziennie przez około 25 dni. Średnio składa około 90 jaj zwanych gnidami, barwy żółtawobiałej z wieczkiem na górnym biegunie. Wielkości 1,0 - 1,5 mm długości. Są one mocowane specjalnym "cementem" u nasady włosa. Po około 12-14 dniach z jaj klują się młode wszy. Rozwój osobniczy trwa po wykluciu się z jaja około 14 dni. Długość życia wszy świńskiej wynosi około 35 dni. Pasożytuje na skórze owłosionej głównie w okolicy nasady uszu, na karku, na bokach ciała. W przypadku silnego opadnięcia może występować na całym ciele. Kosmopolityczny.
