23 research outputs found
The moose nose bot fly Cephenemyia ulrichii Brauer (Diptera: Oestridae) reported in Norway for the first time
Our conclusion is that C. ulrichii has reached the northeastern part of Norway (Pasvik). A further expansion of this parasite may be expected in Norway as well as in southern Sweden. This study shows that moose can be sampled for C. ulrichii with the described technique in the hunting season when the larvae are in their first instar
The timing and departure rate of larvae of the warble fly Hypoderma (= Oedemagena) tarandi (L.) and the nose bot fly Cephenemyia trompe (Modeer) (Diptera: Oestridae) from reindeer
The emergence of larvae of the reindeer warble fly Hypoderma (= Oedemagena) tarandi (L.) (n = 2205) from 4, 9, 3, 6 and 5 Norwegian semi-domestic reindeer yearlings (Rangifer tarandus tarandus (L.)) was registered in 1988, 1989, 1990, 1991 and 1992, respectively. Larvae of the reindeer nose bot fly Cephenemyia trompe (Moder) (n = 261) were recorded during the years 1990, 1991 and 1992 from the same reindeer. A collection cape technique (only H. tarandi) and a grating technique (both species) were used. In both species, dropping started around 20 Apr and ended 20 June. Peak emergence occurred from 10 May - 10 June, and was usually bimodal. The temperature during the larvae departure period had a slight effect (significant only in 1991) on the dropping rate of H. tarandi larvae, and temperature during infection in the preceding summer is therefore supposed to explain the uneven dropping rate. This appeared to be due to the occurrence of successive periods of infection caused by separate periods of weather that were favourable for mass attacks by the flies. As a result, the temporal pattern of maturation of larvae was divided into distinct pulses. Departure time of the larvae in relation to spring migration of the reindeer influences infection levels. Applied possibilities for biological control by separating the reindeer from the dropping sites are discussed
The mating sites of the reindeer nose bot fly: not a practical target for control
The reindeer nose bot fly Cephenemyia trompe aggregates on hilltops/mountaintops to mate. Although active only for brief periods on certain days, males have been collected only from such sites. To evaluate possible suppression of the fly population by killing males (by insecticides or traps) at such sites, the density of sites and the number of males at each site were monitored in a summer grazing area of the semidomestic reindeer host (Rangifer tarandus) in Finnmark, northern Norway. In an area of ca. 20 km2, 19 mating sites were detected and examined during 4 hours on one day. The number of males observed at most sites was 5-16 (range 3-60). Minor hilltops had few males but at some sites >20-60 flies were dispersed over an area of at least 100 m2. It is concluded that mating sites in the study area are too numerous, and also used by many beneficial non-target species, to be practical targets for control of the species
The method by which Cephenemyia trompe (Modeer) larvae invade reindeer (Rangifer tarandus)
Laboratory electrostimulated C. trompe (Modeer) females forcefully expelled (sprayed) larvae for 5-20 cm. The watery spray consisted of about 20 tiny droplets containing two to several larvae. Crawling first-instar larvae exhibited negative geotactic and phototropic responses; they were subject to rapid desiccation and became immobile as the tiny droplets dried within a few seconds. When 5-50 larvae from dissectedfemales were dropped in physiological saline onto different areas of the muzzle of restrained reindeer, only larvae placed deep within the nostrils and on the lips crawled out-of-sight down the nostril passage or into the mouth. Drops of larvae placed elsewhere quickly desiccated and the larvae became immobile. Larvae deposited by wild females onto a COz-baited reindeer model with the muzzle, lips and nostrils coated with insect trapping adhesive all were stuck only along the dorsal lip below the philtrum. All experimental evidence supports a natural per os mode of invasion
Reinens hud- og svelgbrems (Oedemagena tarandi L. og Cephenemyia trompe Modeer), økologi og atferd
Dette forskningsprosjektet på de økonomisk viktige artene for reindriften startet i 1983. Prosjektet er et internasjonalt samarbeid mellom forfatterne og med Økologisk Avdeling ved Universitetet i Tromsø under ledelse av professor Odd Halvorsen. Siktemålet med forskningen er å skaffe grunnleggende kunnskaper om disse to bremseartenes biologi, adferd, fysiologi og epidemiologi. Det ligger videre anvendte perspektiver, især når det gjelder mulighetene for biologisk kontroll, til grunn for prosjektet. Utviklingsfondet for reindrift og Universitetet i Tromsø har støttet prosjektet økonomisk. Feltarbeidet har i hovedsak foregått i Vest¬Finnmark
Life history of the reindeer sinus worm, Linguatula arctica (Pentastomida), a prevalent parasite in reindeer calves
Three hypotheses of life cycle have been tested. A direct transmission to reindeer hosts with monoxenous development is the most probable. Abundant parasites are generally thought to have much impact on host populations. When assessing potential damage in reindeer calves, it is essential to look at the total parasitic effect on infracommunity level
The moose throat bot fly Cephenemyia ulrichii larvae (Diptera:
About fifty larvae of Cephenemyia ulrichii Brauer (Diptera: Oestridae), some of them nearly fullgrown
third instars, were found in the throat of a roe deer (Capreolus capreolus) in June 2007 near
Helsinki in Finland. The parasite is considered to be host specific, occurring only in the moose (Alces
alces), and this paper is apparently the first report of a successful infestation in an aberrant host
The moose throat bot fly Cephenemyia ulrichii larvae (Diptera: Oestridae) found developing in roe deer (Capreolus capreolus) for the first time
About fifty larvae of Cephenemyia ulrichii Brauer (Diptera: Oestridae), some of them nearly fullgrown
third instars, were found in the throat of a roe deer (Capreolus capreolus) in June 2007 near
Helsinki in Finland. The parasite is considered to be host specific, occurring only in the moose (Alces
alces), and this paper is apparently the first report of a successful infestation in an aberrant host
On the efficacy of ivermectin against the reindeer sinus worm Linguatula arctica (Pentastomida), with a review on ivermectin treatment in reindeer
This field study compared the infection level of Linguatula arctica in 14 treated and 19 control calves of the reindeer host Rangifer tarandus. Eighty calves were each treated subcutaneously with 1 ml (200-250 Mg/kg) ivermectin primo December, to ensure that a sufficient number of treated animals later would be selected by the herders for slaughtering. The target parasite L. arctica was then in the reproductive stage of its life cycle. The reindeer were slaughtered in ultimo February. In the treated group, one reindeer was found infected (prevalence 7.1, relative density 0,1), whereas the infection level for the 19 untreated animals was much higher (prevalence 68.4, relative density 7,3). Our conclusion is that ivermectin is an effective agent against L. arctica, (and possibly against other pentastomids because of their similar arthropodal nerve system). This is the first report of ivermectin treatment against a pentastomid species. Additionally, the study confirmed that ivermectin was fully effective against the nose bot fly Cephenemyia trompe
Do reindeer aggregate on snow patches to reduce harassment by parasitic flies or to thermoregulate?
During warm, sunny days (Max. temp. 22 °C to 25 °C) C02-baited traps operated at sites on and off snow patches (SP's) in subarctic Norway caught significantly fewer culicids, simuliids and tabanids on snow in both 1985 and 1987. However, for overnight catches (18.30 - 07.30 h) there was no significant difference in the number of culicids caught on versus off SP's. Analysis of videotapes taken in 1987 showed that defensive anti-fly behaviors of reindeer on and off SP's remained low (< 1/4 min) throughout the day. Based on reindeer anti-fly behaviors, harassment was greatest from 10.30 to 12.30 h (Norwegian Standard Time), but reindeer continued to aggregate on SP's while anti-fly behaviors were lowest (13.30 to 20.00 h). Groups of > 150 animals often occupied the entire surface of a snow patch. At the fly densities and climatic conditions encountered it seemed apparent that reindeer intermittently used SP's primarily to thermoregulate following periods of foraging. Almost all reindeer remained on SP's from 11.00 to 12.30 h, but at other times between 08.00 and 19 00 h about half the herd (ca. 800 animals) foraged for about an hour while the other half aggregated on SP's. However, by 20.00 h, during the cooler period when trap catches of mosquitoes were increasing, almost all reindeer had moved off SP's. The small decreases in anti-fly defensive behaviors observed for reindeer on SP's versus animals foraging in snow-free areas indicated that their presence on SP's may have resulted in a minor, coincidental reduction in harassment. Significantly more tabanids were caught during the morning trapping period than at other times, and significantly more mosquitoes were caught during the evening/overnight trapping period than at other times