Numerical Changes and Environmental Utilization in Natural Populations of Drosophila.

1974 ◽  
Vol 22 (2) ◽  
pp. 175 ◽  
Author(s):  
JA Mckenzie ◽  
PA Parsons
Keyword(s):  
Niche Breadth ◽  
Natural Populations ◽  
Common Species ◽  
Drosophila Species

Monthly collections of three Drosophila species were made over a 39-month period. D, melanogaster was found to be the most common species during summer, D. sirnulans during autumn and D. irnrnigrans during winter. Numerical fluctuations were most marked in the first two species and were related to macroenvironmental temperature. The D. irnmigrans population remained relatively constant throughout the year and the number of the species collected was independent of macroenvironmental variation. For all three species the dimensions of the niche were related to macroenvironmental temperature. This result is discussed in relation to the interaction between numbers in the population, the niche breadth of the species and the environment.

scholarly journals Hyperparasitism in caves: bats, bat flies and ectoparasitic fungus

2018 ◽  
Vol 1 ◽  
Author(s):  
Katrine Jensen ◽  
Luísa Rodrigues ◽  
Thomas Pape ◽  
Anders Garm ◽  
Sergi Santamaria ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Natural Populations ◽  
Common Species ◽  
Unique Case ◽  
Male And Female ◽  
Entire Life ◽  
Bat Flies ◽  
Starting Point ◽  
Bat Fly ◽  
Peculiar Case

Bat flies (Nycteribiidae) of the order Diptera are highly specialized bloodsucking ectoparasites living on bats. The life-cycle of the bat flies emphasizes their obligate relationship with their hosts as they spend almost their entire life on bats. Upon mating, the female bat fly carries the larvae internally until the 3rd-instar when it deposits the larvae on the ceiling of the roost occupied by bats. The larvae then form a puparium. After 3-4 weeks the adult bat fly emerges from the puparium and starts searching for a host bat to colonize. Some of these ectoparasitic bat flies themselves are infected with an ectoparasitic fungus of the genus Arthrorhynchus (Laboulbeniales). Ascospores of the fungi attach themselves to the cuticle of the bat fly and develop a very conspicuous haustorium that penetrates into the soft tissues from where it presumably extract nutrition from the hemolymph of the bat flies. This interaction converts the fungus into a hyperparasite. Both the parasite and hyperparasite are obligates and cannot live separate from their hosts. This peculiar case of hyperparasitism remains highly unknown. The bat flies were collected in caves of Portugal, in maternity and hibernation bat seasons, and in the autumn migration period. The most common species of cave-dwelling bat species in Portugal is Miniopterus schreibersii, frequently parasitized with Nycteribia schmidlii and Penicillidia conspicua bat flies. We have studied the prevalence of the Laboulbeniales of the genus Arthrorhynchus in natural populations of bat flies. The site and position of the fungus on male and female bat flies unveils the mechanism of fungal transmission among bat flies, indicating that it occurs during mating behavior. This study is the starting point towards the understanding of this unique case of fungus-insect-vertebrate hyperparasitism interaction. See Suppl. material 1.

scholarly journals Content of pyrrolizidine alkaloids in the leaves of coltsfoot (Tussilago farfara L.) in Poland

2013 ◽  
Vol 82 (4) ◽  
pp. 289-293 ◽  
Author(s):  
Artur Adamczak ◽  
Bogna Opala ◽  
Agnieszka Gryszczyńska ◽  
Waldemar Buchwald
Keyword(s):  
Dry Matter ◽  
Room Temperature ◽  
Pyrrolizidine Alkaloids ◽  
Natural Populations ◽  
Common Species ◽  
Raw Material ◽  
Phytochemical Analysis ◽  
Tussilago Farfara ◽  
Wide Range ◽  
Genetically Determined

Coltsfoot (<em>Tussilago farfara</em> L.) is a common species, widely used in European and Chinese traditional medicine for the treatment of respiratory diseases. However, raw material from this plant contains hepatotoxic pyrrolizidine alkaloids (PAs). The aim of the study was to determine the variability of the level of PAs (senkirkine and senecionine) in leaves of coltsfoot originated from natural populations in Poland. In the phytochemical analysis, 20 samples of <em>T. farfara</em> were used. This plant material was obtained from the Garden of Medicinal Plants in Plewiska near Poznań and originated from different regions of Poland. Coltsfoot leaves were harvested in the middle of July of 2010 and then dried at room temperature. The alkaloid content was detected using the HPLC-DAD method. The amount of PAs in leaves of <em>T. farfara</em> changed in a wide range from 0.06 to 1.04 μg g<sup>−1</sup> of dry matter (DM). The content of senkirkine and senecionine was positively correlated (<em>r</em> = 0.68, <em>P</em> = 0.001). There was no statistically significant correlation between the amount of PAs as well as leaf weight and water content in leaves of <em>T. farfara</em>. Our results showed that a medium-sized leaf of coltsfoot (0.33 g DM) may contain from 0.02 to 0.34 μg of PAs (on average 0.14 μg). The level of PAs was not associated with the region of Poland, but phytochemical similarity of samples was usually visible at the local scale. Coltsfoot leaves are characterized by a high variability of the content of toxic PAs, much higher than in the case of the main active compounds, especially flavonoids and mucilage.<br /> This phytochemical variability is mainly genetically determined (samples came from a garden collection), and it can be increased by environmental factors. Our investigations indicate that Polish natural populations of <em>T. farfara</em> may provide raw material with a low level of toxic PAs.

scholarly journals Seasonal variation in natural populations of Drosophila spp. (Diptera) in two woodlands in the State of São Paulo, Brazil

2006 ◽  
Vol 96 (4) ◽  
pp. 437-444 ◽  
Author(s):  
Felipe Rafael Torres ◽  
Lilian Madi-Ravazzi
Keyword(s):  
Seasonal Variation ◽  
Natural Populations ◽  
Adaptive Strategies ◽  
Sao Paulo ◽  
The State ◽  
Drosophila Species ◽  
Climatic Variables ◽  
São Paulo ◽  
Low Diversity ◽  
High Dominance

The composition and the seasonality of the natural populations of Drosophila species in relation to the climatic variables temperature and rainfall were analyzed from September 1998 through October 1999 by monthly collections, in two woodlands in the Northwest of the State of São Paulo, Brazil. The diversity dominance component curves were inclined, reflecting low diversity and high dominance of few species. Among the 25 species recorded, Drosophila sturtevanti Duda, 1927 was the most frequent and abundant. On the opposite to data in literature, D. paranaensis Barros, 1950 abundance and frequency were greater than those from D. mercatorum Patterson & Wheeler, 1942. A positive correlation between abundance and rainfall was observed for D. nebulosa Sturtevant, 1916. These data are indicative of changes in the populations structure due to new adaptive strategies arised in response to environmental modifications.

Does natural larval parasitism of Lobesia botrana (Lepidoptera: Tortricidae) vary between years, generation, density of the host and vine cultivar?

2006 ◽  
Vol 96 (2) ◽  
pp. 105-110 ◽  
Author(s):  
A. Xuéreb ◽  
D. Thiéry
Keyword(s):  
Natural Populations ◽  
Host Density ◽  
Common Species ◽  
Lobesia Botrana ◽  
First Year ◽  
Cabernet Sauvignon ◽  
Parasitism Rate ◽  
Second Year ◽  
Grapevine Moth ◽  
Grape Cultivars

Abstractpulations of European grapevine moth Lobesia botrana Franc, Sauvignon, Cabernet Sauvignon and Sémillon) using a natural L. botrana population during the first year, and a natural population supplemented with artificially inoculated individuals during the second year. Levels of natural populations of larval parasitoids were measured by their parasitism rate. The ichneumonid Campoplex capitator Aubert was the most common species collected from L. botrana larvae. Its incidence was higher during the spring compared to summer. The overall parasitism rate found on the experimental vineyard varied from 23% in 2000 to 53% in 2001, and was mainly due to C. capitator. Parasitism was not affected by the grape cultivar on which the host developed but was positively correlated with the host density, per bunch or per stock, suggesting that among the five grape cultivars tested, C. capitator females probably do not discriminate between hosts feeding on different grape cultivars, but rather the densities of L. botrana larvae.

scholarly journals Niche Breadth and Overlap of Sphagnum Species in Costa Rica

1995 ◽  
Vol 11 (1) ◽  
pp. 119-127
Author(s):  
Cyrus B. McQueen
Keyword(s):  
Costa Rica ◽  
North America ◽  
South America ◽  
Niche Breadth ◽  
Niche Overlap ◽  
Common Species ◽  
The Common ◽  
Sphagnum Magellanicum

Niche breadth and overlap values of Sphagnum species in Costa Rica are similar to those reported for Sphagnum-dominated peatlands in North America. Sphagnum magellanicum Brid. and S. sparsum Hampe have the broadest niche breadth of the common species in Costa Rica. Although S. sancto-josephense Crum & Crosby has a relatively narrow niche breadth, it is one of the most common species along with S. magellancium and S. sparsum in the Sphagnum habitats of Costa Rica. Niche overlap is high among species with the exception of S. platyphyllum (Braithw.) Warnst. which is found in habitats that are rich in iron. The pH, conductivity, and concentrations of Ca, Fe, Mg, Mn, Na, K, and P of Sphagnum habitats in Costa Rica are similar to those reported for páramo habitats in South America.

Ecological structure of a herpetological assemblage in South India

1987 ◽  
Vol 8 (3) ◽  
pp. 189-202 ◽  
Author(s):  
M. Koshy ◽  
Robert F. Inger ◽  
H.B. Shaffer ◽  
R. Bakde
Keyword(s):  
South India ◽  
Niche Breadth ◽  
Niche Overlap ◽  
Common Species ◽  
Evergreen Forest ◽  
Terrestrial Species ◽  
South Indian ◽  
Tropical Evergreen Forest ◽  
The Western Ghats ◽  
Level Of Analysis

AbstractWe collected detailed microhabitat information on 1460 specimens comprising 52 species of amphibians and reptiles from a small area of tropical evergreen forest in South India. Although most individuals were found in non-riparian situations, the number caught in and along streams was higher than expected on the basis of collecting effort. Very few animals were caught under logs and rocks. When niche breadth values are corrected for variation in sample size, we find no correlation between magnitude of niche breadth and general habitat usage, such as terrestriality vs. arboreality. A cluster analysis of 28 common species using niche overlap values reveals one group of 6 terrestrial species with very high niche overlap values and high co-occurrence within collecting sorties; this group probably represents a genuine terrestrial guild. Another set of 4 terrestrial species is peripherally associated with the first 6, whereas the remaining species show generally low overlap values. Altitudinal restriction is an almost ubiquitous feature of the distribution of species in this fauna, with distinct groups of low (below 300 m), intermediate (300-399 m), and high altitude (above 399 m) taxa roughly corresponding to major shifts in forest types. At a broader level of analysis, we find considerable evidence for local endemism within partially isolated hill ranges in the Western Ghats, suggesting that geographic isolation may be an important contributing factor to the diversity of the South Indian herpetofauna.

scholarly journals A prospective study of inversion polymorphism in natural populations of two Drosophila species from eastern Mexico

Genetika ◽  
2010 ◽  
Vol 42 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Victor Salceda
Keyword(s):  
Prospective Study ◽  
Natural Populations ◽  
The Other ◽  
Drosophila Species ◽  
High Frequencies ◽  
The Third ◽  
Grand Total ◽  
Chromosome Arm ◽  
A Prospective Study ◽  
And Inversion

Relative frequencies for heterozygous inversions in nine populations of D. nebulosa and six of D. willistoni were analyzed. The analysis corresponds to a grand total of 1828 arm chromosomes in which their genotype were determined, of them 404 correspond for each one of the two polymorphic chromosomes, X and III, of D. nebulosa and 204 per chromosome arm in D. willistoni. The more abundant inversions, according to their relative frequencies in D. nebulosa were the XL inversion with 7.9 % and inversion ?A? in the third chromosome with 15.6 %, the remaining inversion found did not reach the ten percent. In the case of D. willistoni the more frequent inversions were for the XL arm inversions ?A? and ?D? with 13.7 and 12.2 percent respectively the remaining five did not reach a ten percent; in the XR arm the higher frequencies were for inversions ?D? and ?E? with 9.3 % each been the other four inversions with values less than five percent; in the IIL arm none of the seven inversions registered had values higher than six percent; inversion ?E? in the IIR arm showed a frequency of 24.5 % and the five remaining barely reached a frequency of 5 %; among the 12 different inversions recorded in the third chromosome, only inversion ?B? surpassed the ten percent in this case with 16.1 %. We must mention that the Standar sequence in all cases, for both species, always had high frequencies as shown in Tables II and III. The corresponding variability for this characteristic is for D. nebulosa 61.4 %.and 72.2% for D.willitoni. Concerning other parameter observed we have the average number of inversions per female in our case for D. nebulosa was 1.4 and for D. willistoni 3.6 which indicate the both species are marginal with respect to the distribution of this character in both species since in the central areas of distribution reach values up to nine inversions per female.

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