No Evidence for Resistance to Fenbendazole in Trichostrongylus tenuis, a Nematode Parasite of the Red Grouse

2010 ◽  
Vol 74 (8) ◽  
pp. 1799-1805 ◽  
Author(s):  
Ruth Cox ◽  
David Newborn ◽  
David Baines ◽  
Christopher J. Thomas ◽  
Thomas N. Sherratt
Keyword(s):  
Nematode Parasite ◽  
Red Grouse ◽  
Trichostrongylus Tenuis

scholarly journals Nematode parasites reduce carotenoid-based signalling in male red grouse

2007 ◽  
Vol 3 (2) ◽  
pp. 161-164 ◽  
Author(s):  
Jesús Martínez-Padilla ◽  
François Mougeot ◽  
Lorenzo Pérez-Rodríguez ◽  
Gary R Bortolotti
Keyword(s):  
Nematode Parasite ◽  
Negative Effects ◽  
Free Living ◽  
Red Grouse ◽  
Carotenoid Concentration ◽  
Nematode Parasites ◽  
Parasite Infections ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis ◽  
First Time

Carotenoids determine the yellow–red colours of many ornaments, which often function as signals of quality. Carotenoid-based signalling may reliably advertise health and should be particularly sensitive to parasite infections. Nematodes are among the commonest parasites of vertebrates, with well-documented negative effects on their hosts. However, to date, little is known about the effects that these parasites may have on carotenoid-based signalling. Tetraonid birds (grouse) exhibit supra-orbital combs, which are bright integumentary ornaments pigmented by carotenoids. We tested the effect of the nematode parasite Trichostrongylus tenuis on signalling in free-living male red grouse Lagopus lagopus scoticus . We show that experimentally reduced nematode infection increases plasma carotenoid concentration and comb redness, demonstrating for the first time that nematodes can influence carotenoid-based signals.

The energetic consequences of parasitism: effects of a developing infection of Trichostrongylus tenuis (Nematoda) on red grouse (Lagopus lagopus scoticus) energy balance, body weight and condition

Parasitology ◽  
1995 ◽  
Vol 110 (4) ◽  
pp. 473-482 ◽  
Author(s):  
R. J. Delahay ◽  
J. R. Speakman ◽  
R. Moss
Keyword(s):  
Energy Balance ◽  
Resting Metabolic Rate ◽  
Red Grouse ◽  
Lagopus Lagopus ◽  
Energy Imbalance ◽  
Daily Energy ◽  
Total Daily Energy Expenditure ◽  
Synchronous Development ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis

SUMMARYThe timing of the energetic consequences of a developing, single-dose infection of Trichostrongylus tenuis larvae was investigated in captive red grouse Lagopus lagopus scoticus. At 12 days post-infection (p.i.), infected birds had a resting metabolic rate 16% greater than controls and thenceforth lost weight at a faster rate than controls. At 16 days p.i. infected birds consumed 38% less energy and excreted 33% less energy than controls. The estimated total daily energy expenditure and energy expended on activity for infected birds at 16 days p.i. were 36% and 83% lower, respectively, than for controls. Infected birds lost condition from 16 days p.i. onwards. The period of energy imbalance at 12–16 days p.i. coincided with development of late 4th-stage larvae into adult worms and the onset of patency. After this, the effects on energy balance diminished. Synchronous development of previously arrested T. tenuis larvae in wild birds in spring probably has similar effects to those reported here and places grouse under conditions of energy imbalance. The observed effects on energy balance provide a possible mechanism by which the parasite can reduce fecundity and survival of infected grouse.

Development and survival of the free-living stages of Trichostrongylus tenuis, a caecal parasite of red grouse Lagopus lagopus scoticus

Parasitology ◽  
1989 ◽  
Vol 99 (1) ◽  
pp. 105-113 ◽  
Author(s):  
J. L. Shaw ◽  
R. Moss ◽  
A. W. Pike
Keyword(s):  
Soil Surface ◽  
Winter Survival ◽  
Free Living ◽  
Red Grouse ◽  
Lagopus Lagopus ◽  
Infective Larvae ◽  
Surface Temperatures ◽  
The Mean ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis

SUMMARYIn the laboratory, yields of infective 3rd-stage larvae of Trichostrongylus tenuis were determined by temperature when moisture was adequate. On the moor, eggs in caecal faeces did not develop to infective larvae during the winter. In summer, development did occur and yields of infective larvae were related to temperature: greatest yields were obtained when mean monthly soil surface temperatures ranged between 76 and 103°C. Rainfall was unimportant, as was desiccation. During summer the mean monthly mortality of infective larvae was 44% but over winter survival was negligible.

Absence of three known benzimidazole resistance mutations in Trichostrongylus tenuis, a nematode parasite of avian hosts

2008 ◽  
Vol 158 (4) ◽  
pp. 302-310 ◽  
Author(s):  
Lucy M.I. Webster ◽  
Paul C.D. Johnson ◽  
Aileen Adam ◽  
Barbara K. Mable ◽  
Lukas F. Keller
Keyword(s):  
Nematode Parasite ◽  
Resistance Mutations ◽  
Benzimidazole Resistance ◽  
Trichostrongylus Tenuis

Faecal egg counts provide a reliable measure of Trichostrongylus tenuis intensities in free-living red grouse Lagopus lagopus scoticus

2004 ◽  
Vol 78 (1) ◽  
pp. 69-76 ◽  
Author(s):  
L.J. Seivwright ◽  
S.M. Redpath ◽  
F. Mougeot ◽  
L. Watt ◽  
P.J. Hudson
Keyword(s):  
Storage Time ◽  
Free Living ◽  
Red Grouse ◽  
Lagopus Lagopus ◽  
Counting Methods ◽  
Faecal Egg Counts ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis ◽  
High Parasite ◽  
Exact Relationship

AbstractThe reliability of different egg counting methods for estimating the intensity of Trichostrongylus tenuis infections in red grouse, Lagopus lagopus scoticus, was investigated in the autumn, when grouse may harbour high parasite intensities. Possible limitations to the use of these methods were also examined. Faecal egg counts were found to accurately estimate T. tenuis worm intensities, at least up to an observed maximum of c. 8000 worms. Two egg counting methods (smear and McMaster) gave consistent results, although the exact relationship with worm intensity differed according to the method used. Faecal egg counts significantly decreased with increasing length of sample storage time, but egg counts were reliable for estimating worm intensity for three weeks. The concentration of eggs in the caecum was also found to reliably estimate worm intensity. However, egg counts from frozen gut samples cannot be used to estimate worm intensities. These results conclude that, despite some limitations, faecal and caecum egg counts provide useful and reliable ways of measuring T. tenuis intensities in red grouse.

Strategies for nematode transmission: selective migration of Trichostrongylus tenuis infective larvae

2001 ◽  
Vol 75 (4) ◽  
pp. 367-372 ◽  
Author(s):  
L.M. Saunders ◽  
D.M. Tompkins ◽  
P.J. Hudson
Keyword(s):  
Calluna Vulgaris ◽  
Nematode Species ◽  
Food Plant ◽  
Red Grouse ◽  
Selective Migration ◽  
Infective Larvae ◽  
Wide Range ◽  
General Response ◽  
Trichostrongylus Tenuis ◽  
Nematode Transmission

Successful transmission of macroparasites is dependent on exposure of susceptible hosts to free-living infective stages. When these hosts are herbivores that feed mostly on a single food plant then natural selection should favour those infective larvae that selectively ascend this main food plant. Red grouse feed predominantly on heather,Calluna vulgaris, so we predict that the infective larvae (L3) of the caecal nematodeTrichostrongylus tenuisselectively locate and ascend heather plants. To determine whether the presence of heather influences the horizontal dispersal ofT. tenuisL3 across soil, the movement of L3 across trays of soil with and without heather was investigated in the laboratory. MoreT. tenuisL3 were recovered from soil when heather was present, implying that larval migration may be influenced by chemical cues produced by heather plants. This was investigated in a second experiment, in which the horizontal dispersal ofT. tenuislarvae was examined in the presence of heather and grass vegetation. This trial was repeated with larvae of a second species,Haemonchus contortus, a nematode whose hosts feed on a wide range of grass and shrub species. Significantly more larvae of both nematode species were recovered in the region of the heather than the grass or controls. This implies thatT. tenuisandH. contortusL3 exhibit selective migration towards heather, perhaps reflecting a general response to plant cues which may be stronger for heather than for grass.

The role of parasite fecundity and longevity in the success of Trichostrongylus tenuis in low density red grouse populations

Parasitology ◽  
1989 ◽  
Vol 99 (2) ◽  
pp. 253-258 ◽  
Author(s):  
J. L. Shaw ◽  
R. Moss
Keyword(s):  
Seasonal Variations ◽  
Reproductive Capacity ◽  
Low Density ◽  
Red Grouse ◽  
The North ◽  
High Prevalence ◽  
Long Life ◽  
Trichostrongylus Tenuis ◽  
Effective Transmission

SummaryThe prevalence of the caecal threadworm Trichostrongylus tenuis in red grouse in the north of Scotland was high despite low grouse densities. Prevalence, intensity and aggregation of threadworms was higher in old than in young grouse. Infections were long-lasting: populations of adult worms could survive for over 2 years in grouse, with little mortality. Parasite egg output decreased with the age of a worm population, largely as a result of a decrease in the fecundity of ageing female worms. Seasonal variations in worm fecundity were also evident.However, there was no evidence of an intensitydependent decrease of worm fecundity with increasing worm numbers in either captive or wild grouse. The long life and high reproductive capacity of T. tenuis probably contribute to its effective transmission and high prevalence.

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