The impact of Arrenurus danbyensis Mullen (Acari: Prostigmata; Arrenuridae) on a population of Coquillettidia perturbans (Walker) (Diptera: Culicidae)

1984 ◽  
Vol 62 (6) ◽  
pp. 1121-1134 ◽  
Author(s):  
Bruce P. Smith ◽  
Susan B. McIver
Keyword(s):  
Egg Production ◽  
Negative Binomial ◽  
Natural Populations ◽  
Adult Life ◽  
Published Data ◽  
Adult Life Span ◽  
Coquillettidia Perturbans ◽  
Host Seeking ◽  
Parasitic Mites ◽  
The Impact

Adult Coquillettidia perturbons (Walker) collected in Algonquin Park, Ontario, Canada, from 1978 to 1980 were parasitized by larval Arrenurus danbyensis Mullen. Up to 87.5% of newly emerged mosquitoes were parasitized. The prevalence of parasites on host-seeking mosquitoes rarely exceeded 30%. This discrepancy is not the result of mites dropping off host-seeking mosquitoes. By comparing pairs of samples over the apparent interval of 1 – 2 days between emergence and host-seeking, it is estimated that 42.5% of the newly emerged were not recruited to the host-seeking population. In the laboratory, no significant effect of parasitic mites on the host's adult life-span or blood-meal size was detected, but there was a significant effect on the host's egg production. The distribution of mites on mosquitoes was characterized by combining the Taylor power law and the negative binomial distribution. With this relationship, the effect of mite parasitism on the host's egg production in the laboratory could be extrapolated to estimate this effect on natural populations. In the population studied, egg production is reduced by approximately 5%. Based on published data, egg production in the first gonotrophic cycle of a population of Anopheles crucians Wiedemann is reduced by up to 35%.

scholarly journals Risk factors for physical inactivity across the adult life span: the impact of depression

2006 ◽  
Vol 18 (6) ◽  
pp. 274-274
Author(s):  
J Walker ◽  
H Christensen ◽  
T Windsor ◽  
A George
Keyword(s):  
Risk Factors ◽  
Life Span ◽  
Physical Inactivity ◽  
Adult Life ◽  
Adult Life Span ◽  
The Impact

Modelling patterns of parasite aggregation in natural populations: trichostrongylid nematode–ruminant interactions as a case study

Parasitology ◽  
1995 ◽  
Vol 111 (S1) ◽  
pp. S135-S151 ◽  
Author(s):  
B. T. Grenfell ◽  
K. Wilson ◽  
V. S. Isham ◽  
H. E. G. Boyd ◽  
K. Dietz
Keyword(s):  
Population Biology ◽  
Negative Binomial ◽  
Natural Populations ◽  
Parasite Load ◽  
Host Immunity ◽  
Moment Closure ◽  
The Mean ◽  
Parasite Aggregation ◽  
The Impact ◽  
The Relationship

SUMMARYThe characteristically aggregated frequency distribution of macroparasites in their hosts is a key feature of host–parasite population biology. We begin with a brief review of the theoretical literature concerning parasite aggregation. Though this work has illustrated much about both the sources and impact of parasite aggregation, there is still no definitive analysis of both these aspects. We then go on to illustrate the use of one approach to this problem – the construction of Moment Closure Equations (MCEs), which can be used to represent both the mean and second moments (variances and covariances) of the distribution of different parasite stages and phenomenological measures of host immunity. We apply these models to one of the best documented interactions involving free-living animal hosts – the interaction between trichostrongylid nematodes and ruminants. The analysis compares patterns of variability in experimental infections of Teladorsagia circumcincta in sheep with the equivalent wildlife situation – the epidemiology of T. circumcincta in a feral population of Soay sheep on St Kilda, Outer Hebrides. We focus on the relationship between mean parasite load and aggregation (inversely measured by the negative binomial parameter, k) for cohorts of hosts. The analysis and empirical data indicate that k tracks the increase and subsequent decline in the mean burden with host age. We discuss this result in terms of the degree of heterogeneity in the impact of host immunity or parasite-induced mortality required to shorten the tail of the parasite distribution (and therefore increase k) in older animals. The model is also used to analyse the relationship between estimated worm and egg counts (since only the latter are often available for wildlife hosts). Finally, we use these results to review directions for future work on the nature and impact of parasite aggregation.

scholarly journals Host-seeking behavior and hourly biting rhythm of vectors in malaria endemic district of Arba Minch area, Southwest Ethiopia

2020 ◽  
Author(s):  
Melkam Abiye Zeru ◽  
Simon Shibru ◽  
Fekadu Massebo
Keyword(s):  
Malaria Vector ◽  
Negative Binomial ◽  
Malaria Vectors ◽  
Malaria Vector Control ◽  
Southwest Ethiopia ◽  
Anopheles Mosquitoes ◽  
Host Seeking ◽  
Human Landing ◽  
Seeking Behavior ◽  
The Impact

Abstract Background The early and outdoor biting behaviors of malaria vectors are among the key challenges in malaria control. Hence, understanding the host-seeking behavior and the peak biting time of malaria vectors is important in malaria vector control programs. This study assessed the host-seeking behavior and hourly biting activity of malaria mosquitoes in Chano Mille village in Arba Minch district, southwest Ethiopia. Methods The first trial was done by keeping cattle together with human that collects the entered mosquitoes in tent, while the other was done by keeping cattle outside a 1 m distance from human collector inside a tent. In both trials, mosquito collation was done inside tents baited by cattle and human using human landing catches (HLC) techniques. Four human volunteers’ were recruited and trained to collect mosquitoes in the four tents from 18:00-24:00 for three months. Two tents were selected randomly for human alone and two for cattle baited collections in the first night and then rotated to minimize the variation due to location of tents and collectors skill. The tent trial was done close to the shore of the Lake Abaya to minimize the interference of other animals on mosquito movement. The peak biting hour of malaria vectors was assessed within a Chano village from 18:00-6:00. Mosquito collation was done both indoor and outdoor by HLC. Morphological speciation of Anopheles mosquitoes was done. The sporozoite infectivity status of Anopheles pharoensis was examined using enzyme-linked immuno-sorbent assay technique. The data was analyzed using a Generalized Estimating Equations with a negative binomial distribution. Results An. pharoensis, An. gambiae complex and An. tenebrosus were the three species documented during the trial. Keeping cattle together with human collector inside the tent attracted 42% ( P < 0.001) more An. pharoensis compared to human alone tent. Also, keeping cattle outside near to a tent with human at 1 m distance, attracted the entering An. pharoensis into the tent inside with human by 46% ( P = 0.002) than human in a tent with no cattle outside the same tent. The impact was not significant for An. gambiae complex and An. tenebrosus. Anopheles pharoensis and An. gambiae complex showed early night biting activity with peak biting from 19.00-20:00 which was significant for both An. gambiae complex ( P < 0.001) and An. pharoensis ( P = 0.015). Anopheles gambiae complex was mainly biting humans outdoor in the village. Conclusions Finally, keeping cattle within and close to human dwellings could increase malaria vectors bite exposure particularly to the zoophilic malaria vector An. pharoensis and, hence deployment of cattle far from human residence could be recommended to reduce the human exposure. The outdoor and early hours biting behavior of the An. gambiae complex could be a threat for success of current indoor based interventions and hence, tools could be designed to reduce this threat.

Feeding ecology of Apocyclops procerus (Copepoda, Cyclopoida) under experimental conditions

Crustaceana ◽  
2015 ◽  
Vol 88 (3) ◽  
pp. 283-297
Author(s):  
M. Guenther ◽  
R. Durst ◽  
W. S. Felismino ◽  
V. T. Pessoa ◽  
S. Neumann-Leitão
Keyword(s):  
Food Supply ◽  
Egg Production ◽  
Feeding Habits ◽  
Adult Life ◽  
Isochrysis Galbana ◽  
First Record ◽  
Chaetoceros Muelleri ◽  
Experimental Conditions ◽  
Adult Life Span ◽  
Copepoda Cyclopoida

Copepods are key links between primary producers and higher pelagics. We investigated, for the first time, under laboratory conditions, some aspects of the reproductive behaviour and feeding preferences of Apocyclops procerus (Copepoda: Cyclopoida) under different conditions of salinity and food supply. This is also its first record for Pernambuco (NE Brazil). The females carry their eggs until their eclosion and present several cycles of egg production without being further fecundated. Egg production and adult life span were not affected by differences in salinity or food supply. Offspring predation was also observed. From the three microalgae species offered to A. procerus individuals, Thalassiosira weissflogii, Chaetoceros muelleri (Ochrophyta) and Isochrysis galbana (Haptophyta), the small round-shaped I. galbana was preferred over the large and spiny diatoms, in spite of its lower nutritional value. The high salinity tolerance and apparently omnivorous feeding habits of A. procerus may enable it to predominate in estuarine waters.

Interactions between the scelionid egg parasitoid Tiphodytes gerriphagus (Hymenoptera) and its gerrid hosts (Heteroptera)

1986 ◽  
Vol 64 (12) ◽  
pp. 2728-2738 ◽  
Author(s):  
John R. Spence
Keyword(s):  
Egg Production ◽  
Adult Life ◽  
Late Summer ◽  
Egg Parasitoid ◽  
The Body ◽  
Host Size ◽  
Lower Growth ◽  
Adult Life Span ◽  
Jelly Coat ◽  
Parasitoid Population

Tiphodytes gerriphagus parasitized eggs of five Gerris and two Limnoporus species in the laboratory and the parasitoids were reared from field-collected eggs of G. buenoi, G. comatus, G. pingreensis, L. dissortis, and L. notabilis. Eggs of G. buenoi and L. dissortis were parasitized over about 80% of development. Wasps preferred eggs of G. buenoi over those of L. dissortis, which were larger but covered by a jelly coat. However, under field conditions, eggs of L. dissortis laid at the water surface were parasitized more than submersed eggs of Gerris species. Host size (= species) had no apparent effect on adult life-span but affected the body length of adult parasitoids. Size of females was affected more than that of males and lifetime fecudity also varied with host size. Parasitoids laid most of their eggs during the first 4 days after emergence, averaging 8–11 parasitized hosts per day. Tiphodytes gerriphagus was reared from eggs of Limnoporus collected throughout western Canada. Rates of parasitism peaked just after egg production by L. dissortis, suggesting selection for early oviposition by gerrids. Most Limnoporus populations were heavily parasitized by late summer, but in some temporary or newly created habitats, rates of parasitism were lower. Growth of the parasitoid population at a new habitat was slower than at nearby ponds with large resident wasp and gerrid populations, and the lower parasitoid abundance was associated with greater production of L. dissortis. Adults of T. gerriphagus appear to overwinter in gerrid eggs at the bottom of ponds. At temporary sites, wasps may fail to survive the winter and recolonize more slowly than Limnoporus. Interaction with parasitoids may explain the patchy nature of L. dissortis distribution and its restriction to temporary habitats. Presence of T. gerriphagus may also affect the outcome of competitive interactions among gerrid species.

scholarly journals Experimental increase in fecundity causes upregulation of fecundity and body maintenance genes in the fat body of ant queens

2021 ◽  
Vol 17 (2) ◽  
Author(s):  
Matteo Antoine Negroni ◽  
Barbara Feldmeyer ◽  
Susanne Foitzik
Keyword(s):  
Egg Production ◽  
Fat Body ◽  
Adult Life ◽  
Molecular Regulation ◽  
Expression Of Genes ◽  
Egg Removal ◽  
Opposing Effects ◽  
Queen Larvae ◽  
Reproductive Individual ◽  
The Impact

In most organisms, fecundity and longevity are negatively associated and the molecular regulation of these two life-history traits is highly interconnected. In addition, nutrient intake often has opposing effects on lifespan and reproduction. In contrast to solitary insects, the main reproductive individual of social hymenopterans, the queen, is also the most long-lived. During development, queen larvae are well-nourished, but we are only beginning to understand the impact of nutrition on the queens' adult life and the molecular regulation and connectivity of fecundity and longevity. Here, we used two experimental manipulations to alter queen fecundity in the ant Temnothorax rugatulus and investigated associated changes in fat body gene expression. Egg removal triggered a fecundity increase, leading to expression changes in genes with functions in fecundity such as oogenesis and body maintenance. Dietary restriction lowered the egg production of queens and altered the expression of genes linked to autophagy, Toll signalling, cellular homeostasis and immunity. Our study reveals that an experimental increase in fecundity causes the co-activation of reproduction and body maintenance mechanisms, shedding light on the molecular regulation of the link between longevity and fecundity in social insects.

scholarly journals Predictors of Listening-Related Fatigue Across the Adult Life Span

2021 ◽  
pp. 095679762110164
Author(s):  
Ronan McGarrigle ◽  
Sarah Knight ◽  
Benjamin W. Y. Hornsby ◽  
Sven Mattys
Keyword(s):  
Sensory Processing ◽  
Process Analysis ◽  
Adult Life ◽  
Auditory Attention ◽  
Adult Life Span ◽  
Mediation Analyses ◽  
Age Related ◽  
Sensory Processing Sensitivity ◽  
The Impact ◽  
Age Related Changes

Listening-related fatigue is a potentially serious negative consequence of an aging auditory and cognitive system. However, the impact of age on listening-related fatigue and the factors underpinning any such effect remain unexplored. Using data from a large sample of adults ( N = 281), we conducted a conditional process analysis to examine potential mediators and moderators of age-related changes in listening-related fatigue. Mediation analyses revealed opposing effects of age on listening-related fatigue: Older adults with greater perceived hearing impairment tended to report increased listening-related fatigue. However, aging was otherwise associated with decreased listening-related fatigue via reductions in both mood disturbance and sensory-processing sensitivity. Results suggested that the effect of auditory attention ability on listening-related fatigue was moderated by sensory-processing sensitivity; for individuals with high sensory-processing sensitivity, better auditory attention ability was associated with increased fatigue. These findings shed light on the perceptual, cognitive, and psychological factors underlying age-related changes in listening-related fatigue.

scholarly journals Recent advances in the Mediterranean researches on zooplankton: from spatial–temporal patterns of distribution to processes oriented studies

2010 ◽  
Vol 1 (2) ◽  
pp. 295 ◽  
Author(s):  
Serena Fonda Umani ◽  
Marina Monti ◽  
Roberta Minutoli ◽  
Letterio Guglielmo
Keyword(s):  
Egg Production ◽  
Grey Literature ◽  
Common Species ◽  
Published Data ◽  
Interannual Fluctuations ◽  
Recurrent Patterns ◽  
The Impact ◽  
Pelagic Communities ◽  
Heterotrophic Production

In this review we focus on research performed by Italian scientists on pelagic communities, from microzooplankton to micronekton, mainly in the Italian Seas. We considered published data, mostly as grey literature, and unpublished ones. Firstly we describe data collected over a time span of more than 30 years, during several cruises all around the Italian peninsula on zooplankton composition and distribution. We identified rare vs. common species, which enhanced biodiversity of the pelagic ecosystem. Time series, some also very long, allowed us to describe seasonal recurrent patterns, interannual fluctuations and recent shifts driven by climatic changes. More recently Italian researches were processes oriented and we analyzed results obtained on the impact of predation of both micro- and mesozooplankton on both autotrophic and heterotrophic preys. Carbon fluxes through zooplankton components were variable in space and time, but accounted for important phytoplankton losses, and when this resource became scarce they relied on heterotrophic production. Through respiration measurements of mesozooplankton another aspect of the C flux was estimated showing an increase in C demand in the most oligotrophic area. Egg production by copepods appeared to be mostly controlled by temperature and quantity/quality of available food.

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