Abundance and stability of populations of chewing lice (Phthiraptera: Amblycera and Ischnocera) infesting two species of woodpeckers (Aves: Piciformes: Picidae)

2018 ◽  
Vol 150 (2) ◽  
pp. 180-189 ◽  
Author(s):  
Robert J. Lamb ◽  
Terry D. Galloway
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Population Variability ◽  
The Other ◽  
Population Stability ◽  
Mean Intensity ◽  
Chewing Lice ◽  
The Mean ◽  
Louse Species ◽  
Colaptes Auratus

AbstractThe annual abundance of chewing lice (Phthiraptera) was recorded from 1996 to 2015 in Manitoba, Canada, on two species of woodpeckers (Piciformes: Picidae). Yellow-bellied sapsuckers (Sphyrapicus varius (Linnaeus)) were infested with Menacanthus pici (Denny) (Amblycera: Menoponidae) and Penenirmus auritus (Scopoli) (Ischnocera: Philopteridae); northern flickers (Colaptes auratus (Linnaeus)) were also infested with M. pici, as well as two other Ischnocera, Penenirmus jungens (Kellogg) and Picicola porisma Dalgleish. The mean annual abundance varied from nine to 51 lice per bird for the four species, with prevalence, mean intensity, sex ratio, and nymphs per female also varying among louse species. Menacanthus pici populations on both hosts were unstable: abundance rose over two decades because of increasing prevalence, whereas the abundance of the other three louse species fluctuated around a mean. Population variability was similar for the lice on both hosts, with the metric, PV, ranging from 0.41 to 0.51 on a 0–1 scale, once the effect of the trend in abundance for M. pici had been removed. Although the population dynamics for species of lice on these two woodpeckers were distinct, inter-specific differences in population stability were less pronounced than observed in the few other species of bird lice studied in this way.

scholarly journals Chewing lice (Phthiraptera: Amblycera, Ischnocera) from chukars (Alectoris chukar) from a pheasant farm in Jinacovice (CzechRepublic)

2012 ◽  
Vol 50 (No. 5) ◽  
pp. 213-218 ◽  
Author(s):  
O. Sychra
Keyword(s):  
Czech Republic ◽  
Species Diversity ◽  
The Other ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Alectoris Chukar ◽  
Louse Species ◽  
First Time

One hundred and twenty captive chukars (Alectoris chukar) and other hosts from a pheasant farm in Jinacovice (Czech Republic) were searched for chewing lice from July 2003 to April 2004. Seven species of chewing lice were found on chukars: Amyrsidea perdicis, Menacanthus pallidulus, Menopon gallinae (Amblycera); Goniodes colchici, Lipeurus maculosus, Goniocotes microthorax and Cuclotogaster heterographus (Ischnocera). Except for the last two mentioned species, the other five louse species are recorded for the first time on chukars. The prevalence, mean intensity of infestation and mean abundance of the lice from chukars were recorded. The species diversity and distribution of chewing lice from another eight species of gallinaceous birds kept in the pheasant farm were also recorded.

Seasonal population dynamics of Neoechinorhynchus qinghaiensis in the carp, Gymnocypris przewalskii przewalskii, from Qinghai Lake, China

2001 ◽  
Vol 75 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Yang Tingbao ◽  
Liao Xianghua
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Feeding Habits ◽  
Host Population ◽  
Qinghai Lake ◽  
Mean Intensity ◽  
Gymnocypris Przewalskii ◽  
The Mean ◽  
Seasonal Population ◽  
Seasonal Population Dynamics

Studies on the seasonal population dynamics ofNeoechinorhynchus qinghaiensis(Acanthocephala: Neoechinorhynchidae) in its fish hostGymnocypris przewalskii przewalskiiin the Qinghai Lake, China, were carried out with samples taken in May 1991, August 1992, November 1992 and February 1993. Prevalences were higher than 44% in all seasons. The mean intensity of infection was above 124 worms per fish. The maximum intensity of worms recovered from a single fish was 1402 in the autumn of 1992. Differences in the mean abundance, mean intensity and prevalence are not statistically significant relative to season and this is likely to be related to the stable temperatures recorded at the bottom of Qinghai Lake. Over-dispersed distributions ofN. qinghaiensisin the host population, due to heterogeneity and feeding habits, were observed in all seasons. The size composition of both sexes ofN. qinghaiensisshowed males to be less than 3.5 mm and females between 0.5 and 4.25 mm, with the main recruitment phase in the worm populations occurring in the autumn, extending through winter and spring with the lowest recruitment occurring in the summer. The maturation and copulation of worms were mainly focused in the summer season. The sex ratio of female to male was both high in winter (1.51:1) and spring (1.48:1). The higher proportion of females and the change in the worm sex ratio in winter can be attributed to the reduced longevity of male worms. As immature male worms exhibit a higher proportion of the worm population than females in all seasons, further studies are needed to determine if such a situation compensates for the shorter life span of males.

Chewing lice (Phthiraptera: Amblycera and Ischnocera) infesting woodpeckers and sapsuckers (Aves: Piciformes: Picidae) in Manitoba, Canada

2016 ◽  
Vol 148 (5) ◽  
pp. 520-531 ◽  
Author(s):  
Terry D. Galloway ◽  
Robert J. Lamb
Keyword(s):  
Louse Infestation ◽  
Mean Intensity ◽  
Chewing Lice ◽  
Northern Flicker ◽  
Picoides Pubescens ◽  
Louse Species ◽  
Colaptes Auratus ◽  
Pileated Woodpeckers ◽  
Picoides Villosus

AbstractFive species of woodpeckers (Piciformes: Picidae) in Manitoba, Canada were examined for chewing lice (Phthiraptera: Amblycera and Ischnocera): downy woodpecker (DOWO) (Picoides pubescens (Linnaeus), n=56), hairy woodpecker (HAWO) (Picoides villosus (Linnaeus), n=32), pileated woodpecker (PIWO) (Dryocopus pileatus (Linnaeus), n=12), northern flicker (NOFL) (Colaptes auratus (Linnaeus), n=223), and yellow-bellied sapsucker (YBSA) (Sphyrapicus varius (Linnaeus), n=192). Seven species of lice were collected (total number=40 613): Menacanthus pici (Denny) from all species of woodpeckers, Brueelia straminea (Denny) from both species of Picoides Lacépède, Penenirmus jungens (Kellogg) from northern flicker, Penenirmus auritus (Scopoli) from all species of woodpeckers examined except northern flickers, Picicola porisma Dalgleish from northern flickers, Picicola snodgrassi (Kellogg) from both species of Picoides, and Picicola marginatulus (Harrison) from pileated woodpeckers. Prevalence for total louse infestation ranged from 32.3% to 85.7% (NOFL>YBSA>PIWO>DOWO>HAWO). Mean intensity for total lice ranged from 29.2 to 232.4 (PIWO>NOFL>HAWO>YBSA>DOWO). Infestation parameters for each louse/host combination are provided. Distribution of louse infestations was highly aggregated. In all louse/host combinations, either females were more prevalent than males or there was no significant deviation from 50:50. There was a tendency for louse species to co-occur on the same host specimen.

The population dynamics of metacercariae of Apatemon gracilis (Trematoda: Digenea) in three species of lake-dwelling leeches

Parasitology ◽  
1986 ◽  
Vol 93 (3) ◽  
pp. 517-530 ◽  
Author(s):  
S. M. Spelling ◽  
J. O. Young
Keyword(s):  
Population Dynamics ◽  
Relative Density ◽  
Sexual Maturity ◽  
Egg Production ◽  
Seasonal Pattern ◽  
Distinct Pattern ◽  
The Other ◽  
Mean Intensity ◽  
Density Values ◽  
Host Mortality

SUMMARYMonthly samples of the leeches Erpobdella octoculata, Glossiphonia complanata and Helobdella stagnalis were taken over a two-year period from an eutrophic, English lake to detect metacercariae of the trematode, Apatemon gracilis. In each cohort of each of the three leeches, prevalence was low in young individuals, rose to a peak in autumn/winter, and then declined until the cohort had almost died out; in E. octoculata and H. stagnalis a final brief increase occurred. Mean intensity and relative density values followed a similar seasonal pattern of change to that of prevalence in these last two species, but in G. complanata values fluctuated irregularly with no distinct pattern. The frequency distribution of the parasite in G. complanata was highly over-dispersed, but less so in the other two species. Infected E. octoculata reached sexual maturity. The parasite reduced egg production in G. complanata and H. stagnalis, but only by maximum values of 2·5 and 9% respectively. This reduction in fecundity is low compared to the subsequent high mortality, at 95% or more, of newly recruited young from as yet unidentified causes. Parasite-related host mortality was difficult to assess in young leeches, but there was some evidence for its occurrence in older leeches of E. octoculata and H. stagnalis. However, this is unlikely to play a prominent role in the control and regulation of lacustrine leech populations.

Cycle de développement, croissance et production de Pisidium amnicum (Mollusca: Bivalvia) dans le Saint-Laurent (Québec)

1981 ◽  
Vol 59 (12) ◽  
pp. 2350-2359 ◽  
Author(s):  
B. Vincent ◽  
G. Vaillancourt ◽  
N. Lafontaine
Keyword(s):  
Population Dynamics ◽  
Sexual Maturity ◽  
Dry Weight ◽  
Mortality Rates ◽  
The Other ◽  
Annual Production ◽  
Bithynia Tentaculata ◽  
The Mean ◽  
Total Dry Weight ◽  
St Lawrence River

The population dynamics of Pisidium amnicum have been studied in one population of the St. Lawrence River over a 2-year period during which 19 samples were taken. The species can live up to 3 years and it is iteroparous; individuals generally attain sexual maturity after 1 year and they reproduce twice, once at 2 and once at 3 years of age. In adults, mortality is lower in winter than during the rest of the year and mortality rates are twice as high during the 1st year than during the 2nd year. Total dry weight (PT, in milligrams) is related to maximum length (L, in millimetres) according to the equation PT = 0.0283∙L3,80 and flesh dry weight (PC, in milligrams) is related to length as follows: PC = 0.007∙L3,18. The annual production to mean biomass (P/B) ratio is 1.4, the mean annual production being 1.298 mg/m2 of total dry weight and 107 mg/m2 of flesh weight. Comparing these results with those obtained for the gastropod Bithynia tentaculata in the same environment and at the same period of the year has shown that the growth of Pisidium amnicum is far less influenced by the temperature regime than that of the other species and that its production is at least 10 times lower.

Biased sex ratios and parasite mating probabilities

Parasitology ◽  
1993 ◽  
Vol 107 (3) ◽  
pp. 287-295 ◽  
Author(s):  
R. M. May ◽  
M. E. J. Woolhouse
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Mating System ◽  
Sex Ratios ◽  
Theoretical Framework ◽  
Main Body ◽  
Female Mating ◽  
The Mean ◽  
Mated Female

SummaryAn earlier paper (May, 1977) developed a theoretical framework for exploring the consequences of dioecy for the population dynamics of schistosomes, assuming an unbiased sex ratio. This paper extends the analysis to biased sex ratios, as have been reported in practice. We consider the relationships of the mean number and distribution of worms among hosts, the sex ratio, and the mating system (monogamous or polygamous) to: (i) the female mating probability, Φ the prevalence of mated female worms. Ω: and (iii) the mean number of mated female worms per host, ξ. Among other results, we show how high values of Φ are associated with male-biased sex ratios and polygamous mating; that Ω is independent of the mating system and is relatively unaffected by the sex ratio; and that ξ is maximal for unbiased sex ratios given monogamous mating, and for female-biased sex ratios if mating is polygamous. These results, together with the confounding effects of the mean number and distribution of worms, are described in detail in the main body of the paper.

THE EFFECTS OF SUPERNUMERARY CHROMATIN IN THREE SPECIES OF GRASSHOPPER

1974 ◽  
Vol 16 (2) ◽  
pp. 285-296 ◽  
Author(s):  
Gilbert L. Schroeter ◽  
Godfrey M. Hewitt
Keyword(s):  
Life Cycle ◽  
Chiasma Frequency ◽  
Genetic Material ◽  
B Chromosomes ◽  
Population Variability ◽  
The Other ◽  
Direct Effects ◽  
Apparent Effect ◽  
Other Hand ◽  
The Mean

The chiasma frequencies in males of three species of grasshopper with and without B-chromosomes and supernumerary segments were scored at diplotene. The partially heterochromatic B's found in some individuals of Chimarocephala pacifica pacifica have no effect on chiasma frequencies. On the other hand, heterochromatic supernumerary segments in Oedaleonotus phryneicus males significantly increase the mean chiasma frequencies over individuals without them but not the between-cell variances. In Camnula pellucida neither the mitotically unstable B's nor supernumerary segments have any apparent effect on chiasma.frequencies. The supernumerary elements in Chimarocephala pacifica and Camnula pellucida may, however, produce other effects during the life cycle These and previous observations suggest that polymorphism involving extra genetic material in grasshoppers can result in increased population variability via two different means: (1) by producing variation in chiasma frequency or (2) through direct effects in the individuals possessing it. The importance of such a mechanism for producing variation is discussed.

Efficacy of Gabapentin in the Treatment of SUNCT Syndrome

Cephalalgia ◽  
2008 ◽  
Vol 28 (12) ◽  
pp. 1339-1342 ◽  
Author(s):  
M Etemadifar ◽  
AH Maghzi ◽  
M Ghasemi ◽  
A Chitsaz ◽  
M Kaji Esfahani
Keyword(s):  
Side Effects ◽  
Case Reports ◽  
The Other ◽  
Side Effect Profile ◽  
Open Label ◽  
Mean Intensity ◽  
Sunct Syndrome ◽  
Before And After ◽  
The Mean ◽  
Pre Treatment

This study was designed to evaluate the efficacy of gabapentin (GBP) in the treatment of SUNCT syndrome on a relatively large sample of Persian patients. Eight patients with SUNCT syndrome underwent a 4-week, open-label, daily treatment of 600-900 mg GBP. The frequency, intensity and duration of attacks were compared before and after the trial. After 4 weeks of treatment, intensity, duration and frequency of headaches were significantly ( P< 0.05) reduced. In addition, five patients (62.5±) were completely relieved from headaches, and in the other three patients the mean intensity, frequency and duration of headaches were decreased notably. In this study, GBP was well tolerated and no unfavourable side-effects were reported. After the end of the trial all patients continued the medication, and after 3 months none reported undesired side-effects or return of the headaches to the pre-treatment status. Our patients had a significant response to GBP, and considering other case reports on the effectiveness of GBP in the treatment of SUNCT syndrome, we propose that, taking into account the good side-effect profile and lack of interactions of GBP, this drug could be considered as an option for the treatment of SUNCT.

scholarly journals Study on infestations and biodiversity of metazoan parasites in Channa punctatus (Bloch), Mymensingh region

2019 ◽  
Vol 17 (3) ◽  
pp. 409-416
Author(s):  
Naoshin Farzana ◽  
Jasmin Naher ◽  
Md Abu Zafar ◽  
Kirtunia Juran Chandra ◽  
Gias Uddin Ahmed
Keyword(s):  
The Other ◽  
Channa Punctatus ◽  
Digenetic Trematode ◽  
Female Fish ◽  
Exotic Fish ◽  
Male Fish ◽  
Metazoan Parasites ◽  
Mean Intensity ◽  
The Mean ◽  
Day By Day

An investigation was conducted on infestation and reviewed biodiversity of metazoan parasites in Channa punctatus of Mymensingh region from July 2013 to June 2014. A total of 235 fish were examined and 9 species of four groups of parasites were recorded. They were (i) Euclinostomum multicaecum Tubangui and Masilungan, 1935 (ii) Euclinostomum heterostomum (Rudolphi, 1809) (iii) Genarchopsis goppo Ozaki, 1925 (iv) Allocreadium handiai  Pandey, 1937 (v) Senga ophiocephalina (Tseng, 1933) (vi) Porrocaecum sp. (vii) Ascaridia sp. (viii) Contracaecum sp. (ix) Pallisentis ophiocephali (Thapar, 1930).The maximum (86.67%) prevalence was found in  (86.67%) October and minimum (35.00%) in December whereas the maximum mean intensity (10) was observed in June and the minimum (1.42) was recorded from December. The prevalence was observed higher (68.85%) in smaller size of fish and in case of larger fish the prevalence was lower and the value was (53.62%). On the other hand, the mean intensity (5.45) was higher in smaller fish and lower (3.39) in medium sized fish. Both prevalence and mean intensity was found maximum in female fish than male fish. Among the four groups of parasites, infestation of Digenetic trematode is much higher than Nematoda, Cestoda and Acanthocephala. During the study, a list of parasites reported from Channa punctatus of Indian sub-continent was prepared. It was found that 38 species of Digenea, 4 species of Cestoda, 26 species of Nematoda and 5 species Acanthocephala were recorded. The Biodiversity of parasites seemed to be declined day by day. The responsible factors for this declination may be environmental degradation, entry of exotic fish and modernization of aquaculture etc. J Bangladesh Agril Univ 17(3): 409–416, 2019

Long-term population dynamics of Aphelenchoides besseyi on Oryza sativa in a paddy field, and changes in the pathological and ecological traits of the two populations

Nematology ◽  
2021 ◽  
pp. 1-17
Author(s):  
Shigeru Hoshino ◽  
Katsumi Togashi
Keyword(s):  
Population Dynamics ◽  
Oryza Sativa ◽  
The Other ◽  
Ecological Traits ◽  
Reproduction Curve ◽  
Aphelenchoides Besseyi ◽  
The Mean ◽  
Two Peaks ◽  
Two Populations

Summary An Oryza sativa cultivar inoculated with the white tip nematode, Aphelenchoides besseyi, was cultivated over 18 years to investigate the population dynamics of the nematode and the change in the virulence of nematodes and tolerance/resistance of plants. The mean number of living nematodes per seed (S) showed two peaks, each of which was followed by a 3-year decrease in the S value, during the initial 10 years. The annual reproduction curve between in year and in year t had a peak in a range of of <1.1. The incidence of white tip disease increased with increasing mean number of living nematodes seed−1 in the previous year, whereas the proportion of seeds with living nematodes increased with increasing mean number of living nematodes seed−1 in the current year. Inoculation tests of the nematode cohorts on the seedling cohorts derived from seeds harvested in the same or different years indicated that the initial 6-year interaction between the rice and nematode populations caused the nematodes to increase the incidence of white tip disease and to decrease the degree of seed swelling and the proportion of heavy seeds. On the other hand, the interaction caused the rice plants to prevent the incidence of disease from increasing and the degree of seed swelling and the proportion of heavy seeds from decreasing.

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