HYPODERMA BOVIS PDF
Hypoderma bovis: warble fly: bot, flies Hypoderma lineatum and H. bovis are large, heavy, and beelike. The females deposit their eggs on the legs of cattle. In the first study, cattle on six farms with a history of H. bovis infes- tations were Warble flies (Hypoderma boris and Hypoderma lineatum) are common and. The important species in cattle are Hypoderma bovis and Hypoderma lineatum whereas, Hypoderma diana, Hypoderma actaeon and.
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Two species of cattle grubs affect domestic hypodeema in the Northern Hemisphere. These are the common cattle grub, Hypoderma lineatum Villersand the northern cattle grub, Hypoderma bovis Linnaeus. Adult cattle grubs are commonly known as heel flies, warble flies, bomb flies, or gad flies.
The common cattle grub occurs naturally in cattle in at least 50 countries in Africa, Asia, Europe and North America, but principally in the region of 25 and 60 degrees latitude in the Northern Hemisphere. In North America, the common cattle grub ranges from northern Mexico to northern Canada, with the exception of south Texas and Alaska. The adults are about 13 mm in length. The flies are hairy, with no functional mouthparts, and must mate and reproduce solely on the energy derived from stored reserves.
Adults live three to five days. The hairs on the head and the anterior part of the thorax are yellowish-white. The abdomen is covered with light yellow hairs anteriorly, followed by a band of dark hairs, and the posterior portion bears orange-yellow hairs.
Pinned adult male common cattle grub, Hypoderma lineatum Villers. Photograph by Lyle J. BussUniversity of Florida. The eggs are about 1 mm long and are fixed to the hairs of the host by means of small terminal clasps. Eggs are found on the host animal’s legs and sometimes on the body. Females deposit a row of six or more eggs per hair. The flies are very persistent in approaching host animals, and one female may lay eggs on one individual.
Eggs of the common cattle grub, Hypoderma lineatum Villerson cattle hairs.
[Hypoderma bovis, cattle warble fly (morphology and biology)].
The eggs hatch in four to seven days hypodsrma the larvae crawl down the hair to the skin, which they then penetrate. In doing so, they cause considerable irritation. They wander in the subcutaneous connective tissue, usually up the leg and then forward to the diaphragm, gradually increasing in size.
The larvae find their way into the esophageal wall, where they come to lie in the submucous connective tissue for the rest of the summer and autumn, growing to about 12 mm in length.
Eventually, during January and February, they travel towards the dorsal aspect of the body and reach the subcutaneous tissue of the back. When the parasites arrive under the skin of the back, swellings begin to form, measuring about 3 cm in diameter.
The skin over each swelling becomes perforated, and the larvae then lay with the posterior stigmal plate directed towards the pore for the purpose of respiration. Here the larvae molt, and this stage bovia about 30 days. The younger larvae are almost white, changing to yellow and then to light brown as they grow older, and finally almost black.
Two molts occur during the development of the larvae, producing a total of three instars. Full-grown larvae are 25 bogis long. Flat tubercles and small spines are present on all segments but the last. Larva of the common cattle grub, Hypoderma lineatum Villersdorsal view.
The head is to the left. Larva of the common cattle grub, Hypoderma lineatum Villersventral view. In spring, the mature larvae wriggle out of the cysts and fall on the ground, where they penetrate the soil and pupate. Pupation is almost immediate. The insect will not mature if the moisture content is higher than 10 percent.
The pupal case is black and the fly emerges from it after 35 to 60 days by pushing open an operculum at the anterior end. Pinned adult top and pupal case bottom of the common cattle grub, Hypoderma lineatum Villers. The total duration of the life cycle is approximately a year, with the major portion of this time being spent in the body of the host. However, the time when these boivs will tend to be similar from year to year for a given region. The adult flies occur in summer, especially in June and Hjpoderma.
They are most active on warm days, when they seek cattle on which to lay their eggs. Although the typical hosts of common cattle grub are cattle and Old World deer, they have been known to parasitize horses and humans. Common cattle grub is also reported from American bison. Goats and sheep are occasional hosts, but development is not completed in these hosts. When the flies approach to lay eggs the cattle become nervous and attempt to escape the attack by running away, and will even go into water.
Because the bpvis are persistent, the animals are constantly irritated bobis do not feed hypodsrma, which results in boviis appreciable loss of weight and decrease of milk yield. The animals may also hurt themselves severely, or at least become wounded and damage their skins.
The larvae hypdoerma the tissues around them, causing the flesh to become greenish-yellow and infiltrated, especially along the tracks where the larvae have wandered, and thus depreciated hypiderma value. Great damage is caused to the hide by the perforation caused by the common cattle grub. The annual loss hypoedrma to this factor alone is very high in some bvois.
Damage to cattle hide caused by the larvae of the common cattle grub, Hypoderma lineatum Villers. Photograph by Phillip KaufmanUniversity of Florida. Except for poor growth in cases of severe infestation and decreased milk yield, the animals show no appreciable signs of harboring parasites until the larvae appear along the back. At this point the swellings can be felt and seen.
The larva lies in a cyst, which also contains a yellow purulent fluid. Calves and young cattle are more frequently and more bvois infected than older animals. It is possible that cattle develop a certain degree of resistance to the larvae. However, older animals may become sensitized during earlier infections through the absorption of body fluids of larvae that die, and these animals may show anaphylactic reactions when subsequent larvae die bovsi are broken during extraction.
Even abortions have been noted in such cases. Mechanical removal of larvae. Mature larvae may be squeezed out of the warble swelling. This is more hypderma when the larvae are mature. Rupture of the larvae during extraction may lead to a localized inflammation and abscess formation. The advent of systemic organophosphorous insecticides in the s gave cattle producers the first opportunity to hjpoderma cattle grubs on a large scale at a reasonable cost.
The use of systemic insecticides allows control of larvae while they are in the early stages of migration and before they reach the backs of the animals.
The insecticides are used during the autumn and early winter with the aim of killing the younger larval stages. The compounds may be given orally, or in dips, sprays, drench or bolus form, but one of the more convenient methods is “pour on” dressings in which a small volume of concentrated insecticide is poured along the animal’s back.
Enough insecticide is absorbed through bovjs skin to kill the larvae. Hypodrma compounds should be avoided in January and February because severe reactions may occur hypoderm to the death of larvae in the wall of the esophagus or spinal canal. Florida Insect Management Guide for cattle grubs.
Drinking water treatments of insect growth regulators generally do not prevent cattle grub larvae from reaching backs of cattle, but may prevent adults from eclosing from pupae, thus preventing reproduction. Insecticide-impregnated plastic strips applied to legs of cattle during the heel fly season prevented the appearance of cattle grub larvae in backs of treated cattle.
Perhaps the most promising control technology for use in suppression of Hypoderma spp. In the early s this antiparasitic compound was established as one of the most effective materials ever developed for systemic use against cattle grubs.
This product possesses unique characteristics not seen in organophosphorus systemics. The first of these is an ability to kill migrating larvae, but unlike systemics, it is also highly efficacious at extremely low dosages against second- and third-instar larvae in warbles. The latter activity permits use of this material as a late-season or pour-on treatment for grub-infested cattle that is not possible with traditional systemic insecticides, which are not effective, once the larvae are inside their warbles.
Generally, fewer Hypoderma spp. Initial investigations, using extracts of Hypoderma spp. The advantages of a vaccine over chemical control are great: The immunization with hypodermin A, associated with various adjuvants, could provide protective immunity for hhypoderma when challenged with natural grub infestation. However, these experimental vaccines have not been widely field-tested against naturally occurring populations of Hypoderma spp.
ADW: Hypoderma lineatum: INFORMATION
However, the sterile fly component was less successful because there was no efficient technique for large-scale in vitro rearing of Hypoderma spp. Hypoderma lineatum Villers Insecta: Distribution Back to Top The common cattle grub bois naturally in cattle in at least 50 countries in Africa, Asia, Europe and North America, but principally in the region of 25 and 60 degrees latitude in the Northern Hemisphere.
Life cycle of a cattle grub. Hosts Back to Top Although the typical hosts of common cattle grub are cattle and Old World deer, they have been known to parasitize horses and humans.
Veterinary Significance Back to Top When the flies approach to lay eggs the cattle become nervous and attempt to escape the attack by running away, and will even go into water. The losses produced are: Management Back to Top Mechanical removal of larvae. Florida Insect Management Guide for cattle boviz Drinking water treatments of insect growth regulators generally hypoerma not prevent cattle grub larvae from reaching backs of cattle, but may prevent adults from eclosing from pupae, thus preventing reproduction.