Haematobia thirouxi potans, two methods described for laboratory rearing, adult flies can be fed either on a bovine calf or on bovine blood in vitro

Parafilaria bovicola, field survey of insect vectors collected from cattle, bleeding-point on cows and prepatent period studies, experimental infection of laboratory-raised Musca autumnalis with third-stage larvae, transmission of third-stage larvae to calves (clinical and pathologic findings)

In this study, we retrieved 42 live third-stage larvae from the crop of an infected squab. This condition is known as myiasis, which occurs due to the infestation of fly larvae belonging to the order Diptera in the tissues. The larvae may affect the storage and digestive functions of the crop in squabs. Here, we report the first case of crop myiasis in a pigeon squab, caused by Musca domestica (Diptera: Muscidae), identified using morphological keys.

In 2007 Nevill, Venter, Meiswinkel & Nevill demonstrated that the pupae of five Culicoides species belonging to the Imicola complex of the subgenus Avaritia could readily be differentiated from one another using various morphological characters. Three of the described species, Culicoides bolitinos Meiswinkel 1989; Culicoides loxodontis Meiswinkel 1992 and Culicoides sp. # 107 (= C. kwagga, Meiswinkel, unpublished thesis 1995), were reared from the dung of large herbivores, which included buffaloes, elephants, white and black rhinoceroses and zebras. However, during that study a further two Avaritia species, neither of which belonged to the Imicola complex, were reared from dung and these are the subject of the present study. For the past 20 years the adults of these two new closely related species have been known as Culicoides sp. # 54 pale form (p.f.) Meiswinkel and Culicoides sp. # 54 dark form (d.f.) Meiswinkel. The taxonomic description and formal naming of the adults of these two species has yet to be done. The present description and comparison of their pupae show that they are two clearly distinct species; that there is no group of morphological characters that can be used to differentiate these two species from the previously described five species of the Imicola complex; and finally that there was no difference between the pupae of C. sp. # 54 d.f. nor C. sp. # 54 p.f. reared from the dung of different host animals.

Antiparasitic efficacy of ivermectin against migrating Gasterophilus intestinalis was evaluated in 36 treated and 24 nontreated (n = 12) or vehicle-treated (n = 12) ponies experimentally and naturally infected with G intestinalis and naturally infected with G nasalis. Each pony was experimentally infected with 500 G intestinalis lst instars in 2 divided doses on days -14 and -7 before treatment. On day 0, ivermectin was administered at the rate of 200 microgram/kg of body weight by IV (n = 12) or IM injection (n = 12) or given as an oral paste (n = 12). Ponies were euthanatized and necropsied 21 days after treatment. In each nontreated or vehicle-treated pony, late lst-, lst- to 2nd-instar molt, and early 2nd-instars of G intestinalis were found in the mouth, and 2nd- and 3rd instars of G intestinalis and 3rd instars of G nasalis were found in the stomach. Bots were not found in any ivermectin-treated pony and, thus, ivermectin was 100% effective against oral and gastric stages. Adverse reactions were not observed in ponies given ivermectin by IM injection or orally, but 1 pony given the vehicle IV and 1 pony given ivermectin (in the vehicle) IV had an anaphylactic reaction, resulting in death of the ivermectin-treated pony. It was speculated that the adverse reaction was caused by histamines released in response to vehicle components given by IV injection.

Parafilaria bovicola, general appearance, size, developmental times, and site of development of each larval stage in potential vector flies (Musca xanthomelas and M. lusoria)

Two-day old house fly adults were exposed to six insect growth regulators, flufenoxuron, teflubenzuron, triflumuron, diflubenzuron, methoxyfenozide, tebufenozide, as a feed additive (milk + 5% sugar + chemical) in the laboratory for 6 days. The number of eggs deposited by the exposed-adults, viability of the eggs, and F1 larval development were checked. All the IGRs tested were found to have no adverse effect on the reproduction of house fly, except methoxyfenozide (210ppm). The most effective inhibitor to egg hatch was flufenoxuron, followed by teflubenzuron, triflumuron, and diflubenzuron. Exposure to flufenoxuron (over 5ppm), teflubenzuron (over 25ppm), triflumuron (over 125ppm), and diflubenzuron (over 125ppm) reduced egg hatchability to 0 to 1.3%, but lower concentrations of these IGRs were less effective (6.3 to 46.3% egg hatchability). Almost all the larvae emerged from eggs deposited by the adults exposed to diflubenzuron (62.5ppm) and teflubenzuron (12.5ppm) failed to develop into pupae, causing total mortalities of 98% and 100%, respectively. However, two IGRs, methoxyfenozide and tebufenozide, did not inhibit egg hatch and F1 larval development, except methoxyfenozide (210ppm) treatment. These results suggest that these 4 IGRs may be used in the development of autosterilization system for house fly control. However, further work is required to develop delivery systems capable of transferring an effective dose to the fly under field conditions.

A successful attempt was made to mechanically transmit bovine leukosis virus (BLV) from a BLV-infected cow with a normal lymphocyte count to sheep by inoculation with horse fly (Tabanus abactor) mouthparts. After interrupted natural feeding, horse flies were anesthetized with CO2. Mouthparts were severed and pooled into a tissue grinder containing medium. Five inocula containing the mouthparts of 10 flies each, and 5 inocula containing the mouthparts of 20 flies each, were prepared and inoculated SC in the right axilla of 10 BLV antibody-negative sheep. Five additional sheep served as controls. Serum samples were collected at 2-week intervals and tested by agar gel immunodiffusion for BLV antibodies. One sheep injected with 20 mouthparts developed antibodies to BLV at 10 weeks after inoculation. Six months after inoculation with fly mouthparts, 1 BLV antibody-negative sheep was randomly selected from each treatment group and injected, in the left axilla, with 3 ml of blood from the donor cow to confirm susceptibility of the sheep. All 3 sheep developed antibodies to BLV within 4 weeks.

helminth parasites and Oestrus ovis in Karakul sheep, seasonal incidence determined by slaughter of successive groups of tracer lambs each exposed on pasture for 33 days, recommended deworming programme, importance of moving sheep to new pastures immediately after deworming

attempts to transmit Anaplasma marginale to cattle with field collections of Hippobosca rufipes were unsuccessful, 1 of 3 attempts to transmit organism with Stomoxys calcitrans was successful