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.

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The olfactory response of the reindeer nose bot fly,Cephenemyia trompe (Oestridae), to components from interdigital pheromone gland and urine from the host reindeer,Rangifer tarandus

Chemoecology ◽

10.1007/bf01241681 ◽

1993 ◽

Vol 4 (2) ◽

pp. 115-119 ◽

Cited By ~ 6

Author(s):

Bj�rn �. T�mmer�s ◽

Atle Wibe ◽

Arne C. Nilssen ◽

John R. Anderson

Keyword(s):

Rangifer Tarandus ◽

Olfactory Response ◽

Pheromone Gland ◽

Bot Fly ◽

Cephenemyia Trompe

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Epizootiology of the reindeer nose bot fly, Cephenemyia trompe (Modeer) (Diptera: Oestridae), in reindeer, Rangifer tarandus (L.), in Norway

Canadian Journal of Zoology ◽

10.1139/z95-123 ◽

1995 ◽

Vol 73 (6) ◽

pp. 1024-1036 ◽

Cited By ~ 13

Author(s):

Arne C. Nilssen ◽

Rolf E. Haugerud

Keyword(s):

Rangifer Tarandus ◽

Negative Binomial ◽

First Instar ◽

High Infection ◽

Bot Fly ◽

Two Measures ◽

Southern Norway ◽

Major Factors ◽

Cephenemyia Trompe ◽

Host Behaviour

First-instar larvae of the reindeer nose bot fly, Cephenemyia trompe (Modeer) (Diptera: Oestridae), were sampled with a rinsing and sieving technique from 571 semidomesticated reindeer, Rangifer tarandus (L.), from different districts in northern Norway in the infection years 1983, 1984, 1985, 1987, and 1988, and from 44 wild reindeer from southern Norway (infection year 1983). This is the first comprehensive epizootiological study of this parasite from Fennoscandia. The first instar was found between 10 September to 25 May, the second instar from 11 February to 17 May, and the third instar from 3 April to 28 June. Old third-instar larvae were sometimes found trapped in the sinuses of the host. The overall prevalence of infection was 65.2% (range 6.7 – 100%) and the abundance (= relative density) was 11.53 (range 6.7 – 62.7). Individual intensities ranged from 0 to 221. There were significant differences in abundance between some districts and years. Distance and timing of the spring migration of the host are thought to be the major factors causing variability in infection levels between districts, whereas the summer climate during infection greatly influenced the differences between years. The frequency distribution was highly overdispersed (aggregated) and could adequately be described by the negative binomial model (overall parameter, k = 0.29, range 0.03 – 2.64). Heterogeneity in host behaviour during infestation is hypothesized to create this parasite distribution. Two measures of aggregation, Morisita's index of aggregation (IM) and1/k, decreased with larval burden, indicating that factors restricting parasite numbers (negative feedback) start to operate at high infection levels.

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The mating sites of the reindeer nose bot fly: not a practical target for control

Rangifer ◽

10.7557/2.15.2.1167 ◽

1995 ◽

Vol 15 (2) ◽

pp. 55 ◽

Cited By ~ 2

Author(s):

Arne C. Nilssen ◽

John R. Anderson

Keyword(s):

Rangifer Tarandus ◽

Target Species ◽

Northern Norway ◽

Bot Fly ◽

Grazing Area ◽

Cephenemyia Trompe ◽

Number Of Males ◽

Summer Grazing

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.

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