STUDIES ON THE ARTHROPOD FAUNA OF ALFALFA: II. ARTHROPOD–FUNGUS ASSOCIATIONS

1972 ◽  
Vol 104 (9) ◽  
pp. 1405-1412
Author(s):  
A. G. Wheeler
Keyword(s):  
Seasonal Changes ◽  
Immature Stages ◽  
Arthropod Species ◽  
Late Fall ◽  
Medicago Saliva ◽  
Arthropod Fauna

AbstractObservations were made during 1967 to 1969 at Ithaca, N.Y., supplemented by collections at New Cumberland and Carlisle, Pa., on arthropods associated with fungi occurring on alfalfa, Medicago saliva L. Five species of Coleoptera, two species of Diptera, one species each of Collembola and Psocoptera, and nine species of Acari were reared or collected consistently from fungus-covered alfalfa leaves, stems, and seed pods. Attraction to fungi on the plants, principally Alternaria sp., accounted for the presence on alfalfa of arthropod species that normally might be considered as accidentals or visitors. The mycetophagous species thus contributed to the richness of the alfalfa fauna. Immature stages of several species were collected only in late fall or on 3- or 4-year-old plants. The possible role of the fungus-feeding species in seasonal changes in the alfalfa fauna and changes in the fauna in successive years is discussed.

The Role of Predation in Determining Traits of Aedes aegypti (Diptera: Culicidae) and Infection With Zika Virus

2021 ◽  
Author(s):  
Shawna Bellamy ◽  
Barry W Alto
Keyword(s):  
Aedes Aegypti ◽  
Zika Virus ◽  
Life History Traits ◽  
Immature Stages ◽  
Direct Effects ◽  
Infected Blood ◽  
Predator Prey ◽  
Susceptibility To Infection ◽  
Density Reduction

Abstract Non-lethal predator-prey interactions during the immature stages can cause significant changes to mosquito life history traits and their ability to transmit pathogens as adults. Treatment manipulations using mosquitoes Aedes aegypti (L.) and Toxoryhnchites rutilus (Coquillett) were performed during the immature stages to explore the potential impacts of non-lethal interactions on adult susceptibility to infection, disseminated infection and saliva infection of Ae. aegypti following ingestion of Zika virus-infected blood. Treatments inducing density reduction resulted in reduced development time and survivorship to adulthood. However, effects of treatment did not alter infection, dissemination, or saliva infection. These observations indicate that, while non-lethal predation may impact some traits that influence population dynamics and transmission of pathogens, there were no direct effects on mosquito-arbovirus interactions.

scholarly journals Arthropod community structure in pastures of an island archipelago (Azores): looking for local–regional species richness patterns at fine-scales

2004 ◽  
Vol 94 (2) ◽  
pp. 111-121 ◽  
Author(s):  
P.A.V. Borges ◽  
V.K. Brown
Keyword(s):  
Species Richness ◽  
Regional Scale ◽  
Local Scale ◽  
Local Species Richness ◽  
Β Diversity ◽  
Arthropod Species ◽  
Α Diversity ◽  
Local Species ◽  
Richness Patterns

AbstractThe arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

Seasonal changes of SP and NKA in frontal cortex, striatum and testes in the rat. Role of maternal pineal gland

Peptides ◽  
2004 ◽  
Vol 25 (6) ◽  
pp. 997-1004 ◽  
Author(s):  
N Vázquez Moreno ◽  
L Debeljuk ◽  
E Dı́az Rodrı́guez ◽  
C Fernández Alvarez ◽  
B Dı́az López
Keyword(s):  
Pineal Gland ◽  
Frontal Cortex ◽  
Seasonal Changes

scholarly journals The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea Mays L.) in Southeastern Poland

2011 ◽  
Vol 51 (3) ◽  
pp. 210-216 ◽  
Author(s):  
Halina Kucharczyk ◽  
Paweł Bereś ◽  
Zbigniew Dąbrowski
Keyword(s):  
Zea Mays ◽  
Species Composition ◽  
Seasonal Dynamics ◽  
Food Source ◽  
Zea Mays L ◽  
Maize Plant ◽  
Seasonal Abundance ◽  
Immature Stages ◽  
Thrips Species

The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea MaysL.) in Southeastern PolandThrips species composition and seasonal abundance was studied on maize crops during two seasons (2006-2007), in southeastern Poland. Altogether 21 species have been identified, among themFrankliniella tenuicornis(Uzel 1895) andHaplothrips aculeatus(Fabricius 1803) which are a graminicolous species and were eudominants, comprising 96.8% in 2006 and 82.0% in 2007 of all collected specimens. Other species occurred only in low numbers. The frequent and numerous presence ofF. tenuicornisspecies in their immature stages in the samples, confirmed the role of the maize plant as the host.H. aculeatusprobably chose maize as a food source and substitute plant for breeding.

Temperature modulation of photoperiodism and the timing of late-season changes in life history for an aphid, Acyrthosiphon pisum

2011 ◽  
Vol 143 (1) ◽  
pp. 56-71 ◽  
Author(s):  
M.A.H. Smith ◽  
P.A. MacKay ◽  
R.J. Lamb
Keyword(s):  
Sexual Reproduction ◽  
Seasonal Changes ◽  
Acyrthosiphon Pisum ◽  
Late Summer ◽  
Day Length ◽  
Temperature Modulation ◽  
Four Seasons ◽  
Aphid Clone ◽  
Photoperiodic Responses

AbstractWhere winters are severe, aphids reproduce parthenogenetically and viviparously in summer, switch to sexual reproduction in late summer, and produce winter-hardy eggs by the end of the season. The role of day length and temperature in initiating seasonal changes from parthenogenetic to sexual reproduction by pea aphids, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), are described and the selection pressures that affect the timing of this transition are investigated. Over four seasons, a pea aphid clone was sampled from field cages through late summer in southern Manitoba, Canada, and reared in the laboratory to determine the phenotypes of progeny produced as the season progressed. The timing of transitions from one phenotype to another under natural day length and temperature, and the critical day lengths that caused the transitions, coincided with expectations from laboratory studies of photoperiodic responses. Males and mating females appeared later when the weather in August was warm than when it was cool. The timing of seasonal changes was adapted to minimize the physiological time to the end of the season, which maximized the number of asexual summer generations. Ambient temperature modulated the response to day length and fine-tuned the timing of sexual reproduction to adapt for annual variation in autumn weather.

scholarly journals Study on the Influence of Seasonal Diversity Deduction of Landscape Plants on Landscape Vision

2019 ◽  
Vol 136 ◽  
pp. 04104
Author(s):  
Shengju Li ◽  
Xue Wang ◽  
Yaosheng Zhang ◽  
Yuehua Zhang ◽  
Li Lan
Keyword(s):  
Seasonal Changes ◽  
Cold Regions ◽  
Distinctive Features ◽  
Landscape Plant ◽  
Planning And Design ◽  
Different Seasons ◽  
Garden Plants ◽  
Seasonal Diversity ◽  
Plant Configuration

Urban garden landscape is a topic of great concern in the process of modern urban construction. It belongs to the landscape with vitality in the construction process. The plant landscape is also the product of the combination of economy, politics, culture and technology. The cold land plants belong to the only life-changing and cyclical elements in the garden design process. They use the seasonal changes of their distinctive features to realize the planning and design, which can effectively enrich the overall landscape effect. The seasonal changes of garden plants in cold regions mainly include space and color. The seasonal changes of color include leaves, flowers, fruits and branches, and the spatial characteristics are different periods of plants. In the process of realizing the garden configuration, it is important to comprehensively study the seasonal changes of plants, which can effectively improve the role of gardens. The study analyzes the influence of seasonal changes of garden plants on the landscape construction of garden space from three aspects: function, season and beauty. Therefore, the characteristics of seasonal changes of garden plants in cold regions are analyzed, so as to improve the rationality of landscape plant configuration in different seasons, and improve the level of garden landscape construction.

The Role of Foreign Workers in the Seasonal Fluctuations of the French Economy

1986 ◽  
Vol 20 (4) ◽  
pp. 856-874
Author(s):  
Raphaël-Emmanuel Verhaeren
Keyword(s):  
Present Article ◽  
Seasonal Changes ◽  
Immigrant Workers ◽  
Foreign Workers ◽  
Seasonal Fluctuations ◽  
Seasonal Workers ◽  
French Economy

The few studies which have been carried out on foreign seasonal workers in France, only take into account the annual inflows of seasonal immigrants. This present article covers two other aspects of the problem: the seasonal nature of immigration in general, and above all the role of permanent immigrant workers in certain sectors influenced by seasonal changes.

EFFECTS OF PINEALECTOMY ON THE SECRETION OF LUTEINIZING HORMONE, TESTOSTERONE AND PROLACTIN IN RAMS EXPOSED TO VARIOUS LIGHTING RÉGIMES

1979 ◽  
Vol 80 (3) ◽  
pp. 397-405 ◽  
Author(s):  
G. K. BARRELL ◽  
K. R. LAPWOOD
Keyword(s):  
Luteinizing Hormone ◽  
Pineal Gland ◽  
Plasma Levels ◽  
Seasonal Changes ◽  
Peak Plasma ◽  
Plasma Concentrations

Two experiments were carried out to study the effects of controlled lighting régimes on plasma levels of LH, testosterone and prolactin in Romney rams. In the second experiment the rams were either pinealectomized or sham-operated so that the role of the pineal gland in mediating seasonal changes in reproduction could be examined. Levels of testosterone and prolactin were considerably influenced by the lighting schedule. Peak plasma concentrations of testosterone were associated with periods during which the daily photoperiod decreased, whereas plasma levels of prolactin showed a pattern of changes approximately in phase with the lighting cycles. Mean plasma concentrations of LH were low in all groups of rams, which made the detection of significant effects of any treatment very unlikely. Pinealectomy reduced the effects of changes in the daily photoperiod on the patterns of secretion of testosterone and prolactin. These findings establish the pineal gland as an organ which influences the endocrine responses of rams to photoperiodic stimuli and it is concluded that the pineal gland is probably important as a mediator of seasonal reproductive changes in these animals.

Seasonal changes in louse populations on white-tailed deer (Odocoileus virginianus)

1975 ◽  
Vol 53 (8) ◽  
pp. 1047-1054 ◽  
Author(s):  
Thomas G. Watson ◽  
Roy C. Anderson
Keyword(s):  
Environmental Factors ◽  
Solar Radiation ◽  
Head And Neck ◽  
Odocoileus Virginianus ◽  
Seasonal Changes ◽  
Radiation Temperature ◽  
Upper Body ◽  
Immature Stages ◽  
Body Regions ◽  
Biting Lice

The hides of 47 white-tailed deer (Odocoileus virginianus) shot at Long Point, Ontario, between September 1972 and August 1973 were examined for lice. Adult Tricholipeurus lipeuroides were most abundant from January to April and T. parallelus from May to August. The distributions of biting lice changed over the study period, possibly influenced by environmental factors such as solar radiation, temperature, rainfall, and changes in pelage. Solenopotes ferrisi was found throughout the study period. There was no significant change in abundance of the various louse stages throughout the study, although all stages were slightly more numerous during winter. Adults primarily infested the head and neck, while immature stages infested upper body regions. Changes in distribution of lice may be the result of environmental and host pelage changes.

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