Effects of prey resource fluctuation on predation attributes of two sympatric Coccinellidae (Coleoptera)

2015 ◽  
Vol 148 (4) ◽  
pp. 443-451 ◽  
Author(s):  
Desh Deepak Chaudhary ◽  
Bhupendra Kumar ◽  
Geetanjali Mishra ◽  
Omkar
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Consumption Rate ◽  
Acyrthosiphon Pisum ◽  
Experimental Conditions ◽  
Propylea Dissecta ◽  
Consumption Rates ◽  
Prey Resources ◽  
Rearing Condition ◽  
Rate Conversion

AbstractUnder natural conditions, prey resources may fluctuate considerably in space and time; and predators are continuously faced with challenges of resource availability and use. In this study, effects of fluctuations (scarce/optimal/abundant) in biomass of pea aphid (Acyrthosiphon pisum (Harris); Hemiptera: Aphididae) during rearing and experimental conditions on certain predatory attributes (consumption rate/conversion, efficiency/growth rate) of two sympatric aphidophagous Coccinellidae (Coleoptera) were evaluated. Results revealed significant influence of rearing conditions on conversion efficiency and growth rate; and experimental conditions on all three predation attributes of Menochilus sexmaculatus (Fabricius) (Coleoptera: Coccinellidae). Larvae/adults of M. sexmaculatus had similar consumption rates per rearing condition, but exhibited highest and lowest consumption rates when abruptly shifted to abundant and scarce prey experimental conditions. Further, scarce prey reared larvae/adults of M. sexmaculatus displayed highest conversion efficiency and growth rate on optimal/abundant prey experimental condition(s). However, all three predation attributes of larvae/adults of Propylea dissecta (Mulsant) (Coleoptera: Coccinellidae) were influenced substantially by both the rearing and experimental conditions; and scarce prey reared larvae/adults exhibited highest predation attributes on optimal/abundant prey experimental condition(s). Moreover, predation attributes of M. sexmaculatus were higher than P. dissecta on the three experimental conditions. Therefore, this study suggests that M. sexmaculatus has a better compensatory ability to overcome prey resource fluctuation than P. dissecta.

Larval and female footprints as feeding deterrent cues for immature stages of two congeneric ladybird predators (Coleoptera: Coccinellidae)

2014 ◽  
Vol 104 (5) ◽  
pp. 652-660 ◽  
Author(s):  
B. Kumar ◽  
G. Mishra ◽  
Omkar
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Adult Female ◽  
Consumption Rate ◽  
Coccinella Septempunctata ◽  
Feeding Deterrent ◽  
Immature Stages ◽  
Developmental Duration ◽  
Species Specific ◽  
Rate Conversion

AbstractIn the present study predation parameters, i.e. consumption rate, conversion efficiency and growth rate, and total developmental duration of immature stages of two congeneric ladybirds, Coccinella septempunctata (L.) and Coccinella transversalis F., have been evaluated in presence of conspecific and heterospecific fourth instar larval and adult female tracks. We hypothesized that the semiochemicals within larval/adult female tracks might act as foraging/feeding deterrent pheromones (FDPs) and would reduce the predation parameters; and would prolong total developmental duration of ladybird predators. Results of the study positively affirmed our hypothesis. The deterrence in prey consumption and reduction in conversion efficiency and growth rate was density dependent with species-specific variations. Consumption rate, conversion efficiency, and growth rate of larval instars decreased and the total developmental duration of immature stages increased when exposed to an increasing density of zero, two, three, and four conspecific/heterospecific larval/adult female tracks. Between ladybird species, C. septempunctata had higher consumption rate, growth rate, and total developmental durations, whereas conversion efficiency was higher in C. transversalis. Despite the presence of semiochemical tracks as foraging barriers, early instars showed higher conversion efficiencies and growth rates, whereas fourth instars had highest consumption rate in all experimental treatments. The present study, therefore, suggests that semiochemical tracks significantly reduce the predation potential and prolong developmental duration of conspecifics and heterospecifics. They, thus behave as FDP.

scholarly journals Ratio of Land Consumption Rate to the Population Growth Rate- A Case of Metropolitan Gombe

2019 ◽  
Author(s):  
Ishiyaku Abdulkadir ◽  
J Sathish Kumar ◽  
Monica Noon
Keyword(s):  
Growth Rate ◽  
United Nations ◽  
Population Growth ◽  
Urban Areas ◽  
Population Growth Rate ◽  
Consumption Rate ◽  
Urban Expansion ◽  
Impervious Surface ◽  
Consumption Rates ◽  
Land Consumption

United Nations Human Settlements Programme recommended equation and tools for reporting SDG indicator 11.3.1. This indicator aim at one ratio between population growth and land consumption rates in order to promote sustainable urban expansion. Because nowadays urban areas rapidly expand, with increasing rate of surface extent that over sweep the rate at which population grows. Trends.Earth was used for the key Impervious Surface Indices (30m resolution) and informed on urban trend, extent and SDG 11.3.1 of metropolitan Gombe for the periods 2000-2005, 2005-2010, and 2010-2015.The research reveals that SDG 11.3.1 for three periods stand at 0.4194, 0.4292, and 0.3041 respectively. The research also indicate that the population growth rate is greater than the land consumption.

Gastric Digestion, Food Consumption, Feeding Periodicity, and Food Conversion Efficiency in Walleye (Stizostedion vitreum vitreum)

1973 ◽  
Vol 30 (9) ◽  
pp. 1327-1336 ◽  
Author(s):  
William A. Swenson ◽  
Lloyd L. Smith Jr.
Keyword(s):  
Conversion Efficiency ◽  
Consumption Rate ◽  
Early Morning ◽  
Stizostedion Vitreum ◽  
Gastric Digestion ◽  
Stizostedion Canadense ◽  
Force Feeding ◽  
Feeding Periodicity ◽  
Consumption Rates ◽  
Repeated Use

Gastric digestion of walleye, Stizostedion vitreum vitreum, and sauger, Stizostedion canadense, was measured by pumping stomachs at various intervals after experimental meals had been force-fed or voluntarily consumed. No significant differences in digestion rates were found between species or among walleye taken from three lakes. Repeated use of fish in digestion experiments failed to influence results. Gastric digestion rate increased with fish size, but was depressed by increased meal size, food particle size, and by force-feeding experimental meals.Food consumption rate and feeding chronology of the strong 1966 year-class of Lake of the Woods walleye were determined by applying results of laboratory digestion studies to stomach samples. An estimating technique that takes into account the effects of factors shown to influence digestion in the laboratory was developed and used to make calculations for the field population. Consumption averaged 1% of body weight during June, 2% during July, and 3% during August and September. Average temperatures were similar during June and September. Greater consumption during September resulted from higher food availability. Feeding was greatest during night and early morning hours in all months except June when it was continuous. Conversion efficiency of the 1966 year-class was described from estimates of growth and consumption rates for June through September and approximated 20% during each month.

scholarly journals LED Illumination Spectrum Manipulation for Increasing the Yield of Sweet Basil (Ocimum basilicum L.)

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 344
Author(s):  
Md Momtazur Rahman ◽  
Mikhail Vasiliev ◽  
Kamal Alameh
Keyword(s):  
Growth Rate ◽  
Fold Increase ◽  
Photosynthetic Photon Flux Density ◽  
Ocimum Basilicum ◽  
Photon Flux ◽  
Photon Flux Density ◽  
White Led ◽  
Experimental Conditions ◽  
Sweet Basil ◽  
Optimal Illumination

Manipulation of the LED illumination spectrum can enhance plant growth rate and development in grow tents. We report on the identification of the illumination spectrum required to significantly enhance the growth rate of sweet basil (Ocimum basilicum L.) plants in grow tent environments by controlling the LED wavebands illuminating the plants. Since the optimal illumination spectrum depends on the plant type, this work focuses on identifying the illumination spectrum that achieves significant basil biomass improvement compared to improvements reported in prior studies. To be able to optimize the illumination spectrum, several steps must be achieved, namely, understanding plant biology, conducting several trial-and-error experiments, iteratively refining experimental conditions, and undertaking accurate statistical analyses. In this study, basil plants are grown in three grow tents with three LED illumination treatments, namely, only white LED illumination (denoted W*), the combination of red (R) and blue (B) LED illumination (denoted BR*) (relative red (R) and blue (B) intensities are 84% and 16%, respectively) and a combination of red (R), blue (B) and far-red (F) LED illumination (denoted BRF*) (relative red (R), blue (B) and far-red (F) intensities are 79%, 11%, and 10%, respectively). The photosynthetic photon flux density (PPFD) was set at 155 µmol m−2 s−1 for all illumination treatments, and the photoperiod was 20 h per day. Experimental results show that a combination of blue (B), red (R), and far-red (F) LED illumination leads to a one-fold increase in the yield of a sweet basil plant in comparison with only white LED illumination (W*). On the other hand, the use of blue (B) and red (R) LED illumination results in a half-fold increase in plant yield. Understanding the effects of LED illumination spectrum on the growth of plant sweet basil plants through basic horticulture research enables farmers to significantly improve their production yield, thus food security and profitability.

Estimating oxygen consumption rates of arteriolar walls under physiological conditions in rat skeletal muscle

2005 ◽  
Vol 289 (1) ◽  
pp. H295-H300 ◽  
Author(s):  
Masahiro Shibata ◽  
Shigeru Ichioka ◽  
Akira Kamiya
Keyword(s):  
Vascular Tone ◽  
Consumption Rate ◽  
Vascular Wall ◽  
Surrounding Tissue ◽  
Phosphorescence Quenching ◽  
Physiological Conditions ◽  
First Order ◽  
Vascular Walls ◽  
Consumption Rates

To examine the effects of vascular tone reduction on O2 consumption of the vascular wall, we determined the O2 consumption rates of arteriolar walls under normal conditions and during vasodilation induced by topical application of papaverine. A phosphorescence quenching technique was used to quantify intra- and perivascular Po2 in rat cremaster arterioles with different branching orders. Then, the measured radial Po2 gradients and a theoretical model were used to estimate the O2 consumption rates of the arteriolar walls. The vascular O2 consumption rates of functional arterioles were >100 times greater than those observed in in vitro experiments. The vascular O2 consumption rate was highest in first-order (1A) arterioles, which are located upstream, and sequentially decreased downstream in 2A and 3A arterioles under normal conditions. During papaverine-induced vasodilation, on the other hand, the O2 consumption rates of the vascular walls decreased to similar levels, suggesting that the high O2 consumption rates of 1A arterioles under normal conditions depend in part on the workload of the vascular smooth muscle. These results strongly support the hypothesis that arteriolar walls consume a significant amount of O2 compared with the surrounding tissue. Furthermore, the reduction of vascular tone of arteriolar walls may facilitate an efficient supply of O2 to the surrounding tissue.

scholarly journals Comparative Study of a Powerplant Life Consumption Rate When Installed in Two Different Aircraft Variants

Aerospace ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 327
Author(s):  
Ioannis Templalexis ◽  
Ioannis Lionis ◽  
Nikolaos Christou
Keyword(s):  
Air Force ◽  
Consumption Rate ◽  
Low Cycle Fatigue ◽  
Rotor Blades ◽  
Parameter Method ◽  
Great Level ◽  
Consumption Rates ◽  
Life Consumption ◽  
Mission Profile ◽  
Engine Life

The Hellenic Air Force (HAF) operates both EMB-145 and EMB-135 LR versions of Embraer aircraft, used in surveillance and civil missions respectively. These aircraft are equipped with the same version of Rolls Royce, AE 3007 turbofan engine. This study aims to quantify and compare the life consumption rate of this engine when installed in each of the two aircraft variants. Two typical missions, one for each variant, were constructed based on mission profile data dictated by the aircraft commanders. For each mission profile segment, corresponding engine data were matched out of the engine recordings archives held by the Hellenic Air Force. The life consumption rate was based on the Low Cycle Fatigue (LCF) and creep cumulative detrimental effect on the rotor blades of the 1st High-Pressure Turbine stage. For the LCF, the rainflow method was used to determine the respective loading cycles, whereas the Larson - Miller parameter method was used to determine the consumed life fractions due to creep. The main conclusion of the study was that the engine when installed in the EMB-145 military variant, is much more loaded. Despite the fact absolute life consumption values could hide a great level of uncertainty, the comparative outcomes wherein errors are, to a certain extent, cancelled out, could be used as a rule of thumb when monitoring engine life consumption rates.

scholarly journals Design and Analysis of a Modified-atmosphere Package for Minimally Processed Romaine Lettuce

1996 ◽  
Vol 121 (4) ◽  
pp. 722-729 ◽  
Author(s):  
Kevin I. Segall ◽  
Martin G. Scanlon
Keyword(s):  
Shelf Life ◽  
Consumption Rate ◽  
Modified Atmosphere Packaging ◽  
Modified Atmosphere ◽  
Packaging Film ◽  
Romaine Lettuce ◽  
Minimally Processed ◽  
Headspace Gas ◽  
Consumption Rates ◽  
Critical Choice

The first goal of this study was to determine the packaging film O2 permeability required to maintain a steady-state O2 concentration of 3% in modified-atmosphere packaging (MAP) of minimally processed romaine lettuce (Lactuca sativa L.). The second goal of the study was to determine the extent to which MAP could preserve lettuce quality and consequently extend product shelf life. Oxygen consumption rates of commercially prepared lettuce samples were determined in a closed system for each of three atmospheres (3% O2 combined with either 6%, 10%, or 14% CO2). Enzymatic, quadratic, and linear mathematical models were compared to determine which best described the respiratory data. The linear model was the most suitable and was used to predict the O2 consumption rate of the minimally processed romaine lettuce under the desired package headspace gas concentrations. The predicted O2 consumption rate was used to calculate the necessary O2 permeability for the packaging film. Packages (21.6 × 25.4 cm) were constructed from a polypropylene-polyethylene-laminate film with the appropriate O2 permeability. Packaged samples were stored under three modified atmospheres (MAs) (3% O2 combined with either 6%, 10%, or 14% CO2) for 20 days, and headspace gas concentrations, lettuce appearance, and color were evaluated every other day. Growth of pectinolytic and lactic acid bacteria was also studied. The O2 consumption rate of the lettuce decreased with increasing CO2 levels. The O2 levels in the MA packages equilibrated at 7% to 11%. Compared to a control atmosphere of air, MAP delayed the development of tissue discoloration. Preliminary results indicated no effect of MAP on microbial growth. Of the three CO2 levels, 10% was slightly more effective than 6% and 14%. Critical choice of packaging permeabilities combined with MAP maintained the quality of minimally processed romaine lettuce and thereby increased shelf life by about 50%.

scholarly journals Effect of Diatomaceous Earth on Growth Rate, Egg Production, Feed Conversion Efficiency and Parasitic Load in Hens Raised on Deep Litter

2021 ◽  
Vol 3 (1) ◽  
pp. 97-103
Author(s):  
Robert Alex Isabirye ◽  
Savino Biryomumaisho ◽  
James Okwee-Acai ◽  
Samuel Okello ◽  
George William Nasinyama
Keyword(s):  
Growth Rate ◽  
Conversion Efficiency ◽  
Egg Production ◽  
Diatomaceous Earth ◽  
Agricultural Research ◽  
Ascaridia Galli ◽  
Feed Conversion ◽  
Indigenous Chicken ◽  
Feed Conversion Efficiency ◽  
Treatment Groups

The efficacy of diatomaceous earth (DE) on growth rate, egg production and on increasing feed conversion efficiency in deep litter raised layer hens was evaluated. The study was conducted at Mukono Zonal Agricultural Research and Development Institute (MUZARDI) in Uganda. Worms were collected from fresh intestines of indigenous chicken obtained from Kalerwe chicken market near Kampala. The DE was mined in Pakwach (formerly Nebbi) district in Northern Uganda. Chickens of the Lohmann Brown breed raised on deep litter were studied. At 7 weeks the birds were divided into 5 treatment groups, A, B, C, D and E each composed of 40 birds. Groups C, D and E were given an oral dose containing 250 embryonated eggs of A. galli while groups A and B were not infected. The chicks were weighed; and subjected to feeding trials as arranged below: A – Non-infected birds on DE (4%) supplemented diet; B –non-infected birds on neither piperazine (a conventional de-wormer) nor DE; C – infected birds on DE supplemented diet; D – infected birds on piperazine; and group E – infected birds on neither DE nor piperazine applied. Fecal samples were collected and analysed in the laboratory biweekly at week 16 till week 22 respectively for fecal egg counts. In a subsequent experiment, day-old layer chicks from Lohmann Brown strain but different from those used in earlier experiments, were used to assess the effect of DE on egg production. At 17 weeks of age the 420 were divided as follows: 6 treatment groups each having 7 replicates and each replicate having 10 birds. This study showed that DE can be used successfully in growing pullet diets to correct nutritional mineral imbalance since it supplies more than 14 trace elements and other elements. Diatomaceous earth also enables pullets to cope with Ascaridia galli load; and 2% DE supplementation did not have significant improvement on egg production as compared to no supplementation at all. However, reduction in egg production was experienced when supplementation with levels of DE higher that 2% was applied. Results from biweekly fecal analyses showed significant differences in fecal egg counts (p<0.05); and treatment by group (p<0.05).

Sign in / Sign up

Export Citation Format

Share Document