Demographic analysis of gummy shark (Mustelus antarcticus) and school shark (Galeorhinus galeus) off southern Australia by applying a generalized Lotka equation and its dual equation

2000 ◽  
Vol 57 (1) ◽  
pp. 214-222 ◽  
Author(s):  
Yongshun Xiao ◽  
Terence I Walker
Keyword(s):  
Total Mortality ◽  
Intrinsic Rate ◽  
Fish Population ◽  
Intrinsic Rate Of Increase ◽  
Demographic Analysis ◽  
Instantaneous Rate ◽  
Dual Equation ◽  
Population Dynamics Model ◽  
Rate Of Increase ◽  
Galeorhinus Galeus

Although Lotka's equation is commonly used for calculating the intrinsic rate of increase with time of a fish population in demographic analysis, its dual equation has never been derived. In this paper, we establish an explicit relationship between the intrinsic rate of increase with time of a fish population and its instantaneous rate of natural mortality from an age-dependent population dynamics model, derive a generalized Lotka equation for calculating the intrinsic rate of increase with time, and derive its dual equation for calculating the intrinsic rate of decrease with age. The virginal intrinsic rate of increase with time of the gummy shark (Mustelus antarcticus) population was calculated as 0.115957·year-1 and its intrinsic rate of decrease with age as -0.312957·year-1. The virginal intrinsic rate of increase with time of the school shark (Galeorhinus galeus) population was calculated as 0.109480·year-1 and its intrinsic rate of decrease with age as -0.216980·year-1. The generalized Lotka equation and its dual equation thus derived imply that both reproductive schedules of a population of animals and its instantaneous rate of total mortality determine its intrinsic rate of increase with time, whereas its reproductive schedules alone determine its intrinsic rate of decrease with age.

Acaricidal activity and sublethal effects of the microbial pesticide spinosad on Tetranychus urticae (Acari: Tetranychidae)

2017 ◽  
Vol 22 (10) ◽  
pp. 1748 ◽  
Author(s):  
Irena Međo ◽  
Bojan Stojnić ◽  
Dejan Marčić
Keyword(s):  
Population Growth ◽  
Tetranychus Urticae ◽  
Sublethal Effects ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Instantaneous Rate ◽  
Leaf Discs ◽  
Rate Of Increase ◽  
Female Longevity ◽  
Microbial Pesticide

Laboratory bioassays were conducted to evaluate the toxicity of the microbial pesticide spinosad to different life stages of the two-spotted spider mite, Tetranychus urticae Koch, as well as its sublethal effects on reproduction and population growth of this important mite pest. The biopesticide was applied to bean primary leaves or leaf discs carrying spider mites using a Potter spray tower (2.7 mg/cm2 aqueous deposit). The following LC50 and LC90 (mg/L) estimates for motile stages were obtained in acute toxicity bioassays: 27.52 and 116.72 (larvae), 36.55 and 136.20 (protonymphs), 82.76 and 721.28 (female deutonymphs), and 61.47 and 457.21 (adult females). Spinosad showed no significant ovicidal action: toxic effect observed after spraying eggs (LC50 = 105.78 mg/L, LC90 = 596.95 mg/L) was the result of its residual action on larvae that hatched from the treated eggs. The effects of spinosad on life history traits and population growth of adult female survivors from treatments with 240, 120 and 60 mg/L were evaluated in two successive 7-day bioassays on untreated leaf discs. In the first bioassay, females that survived treatments as 24 h old eggs and completed their juvenile development on treated leaves had significantly lower gross fecundity, net fecundity and instantaneous rate of increase (ri) but the reduction was merely 4–6%, 9–11%, and 2–3%, respectively. Female longevity was significantly reduced (approximately by half a day) only after treatment with 240 mg/L. In the second bioassay, in which females were treated during their pre-ovipositional period, the treatments with 240 and 120 mg/L significantly reduced their gross fecundity (16–17%), net fecundity (28–31%), ri values (8–9%) and female longevity (approximately by one day). Spinosad effects on the intrinsic rate of increase (rm) and other demographic parameters were evaluated in two successive bioassays in which life tables were constructed for females that survived treatment with 120 mg/L at the egg stage (first demographic bioassay) or pre-ovipositional period (second demographic bioassay). In the first bioassay, the intrinsic rate of increase was significantly higher in treated (rm = 0.278) than control mites (rm = 0.267) as a result of higher net fertility at the beginning of reproduction of treated females. In the second bioassay, treated females had significantly lower rm than control females (0.254 and 0.283, respectively). The results obtained in this study indicate that spinosad, applied against insect pests (at field relevant rates of 60–240 mg/L), could eliminate a part of T. urticae population as well, but survivors would retain a significant potential for population recovery. 

Effects of different almond cultivars on biological and population responses of Schizotetranychus smirnovi (Acari: Tetranychidae)

2021 ◽  
Vol 26 (5) ◽  
pp. 962-972
Author(s):  
Zarir Saeidi ◽  
Alireza Nemati ◽  
Elham Riahi
Keyword(s):  
Growth Parameters ◽  
Reproductive Potential ◽  
Total Mortality ◽  
Intrinsic Rate ◽  
Developmental Time ◽  
Intrinsic Rate Of Increase ◽  
Population Responses ◽  
Rate Of Increase ◽  
The Mean ◽  
Population Growth Parameters

The development, longevity, and reproductive potential of Schizotetranychus smirnovi concerning different almond cultivars including Sefid, Azar, Shokofeh, Shahrood6, Shahrood7, Ferragnes, Shahrood13, Shahrood21, Rabie, Nonpareil, and Mamaei were investigated in the current study. Our results indicated the longest developmental time of females on Shahrood21 (7.35 ± 0.10), while the shortest duration of this parameter was found on Rabie (6.21 ± 0.10) and Nonpareil (5.88 ± 0.17) cultivars. The total mortality ranged from 13.30 to 50.00% on Azar and Shokofeh, respectively. On the majority of cultivars, the highest proportion of mortality among all stages was allocated to larvae which indicated that it was the most sensitive stage. The fecundity of S. smirnovi on Mamaei (34.19 ± 3.60), Sefid (30.50 ± 2.67), and Ferragnes (30.31 ± 3.02) was significantly higher than other cultivars. However, the lowest fecundity (11.21 ± 1.70) was observed on Shokofeh cultivar. Moreover, different cultivars resulted in significant differences in all population growth parameters. Azar had the highest value of both intrinsic rate of increase (r) (0.2675 ± 0.0164) and finite rate of increase (λ) (1.3067 ± 0.0213), whereas the value of these parameters on Shokofeh and Shahrood21 were significantly lower than other cultivars. The mean generation time (T) ranged from 9.51 ± 0.16 on Shahrood7 to 11.69 ± 0.39 d on Shahrood21 cultivar. According to our results, Mamaei, Nonpareil, Rabie, Ferragnes and Azar cultivars were more susceptible, while Shokofeh, Shahrood21, and Shahrood13 seemed to be more tolerant to S. smirnovi.

Influence of temperature on the development and reproduction of Cinara cedri (Hemiptera: Aphidoidea: Lachninae)

2021 ◽  
pp. 1-6
Author(s):  
Yingchao Ji ◽  
Guohua Li ◽  
Chenggang Zhou ◽  
Shuyan Yin
Keyword(s):  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Threshold Temperature ◽  
Reproduction Rate ◽  
Cedrus Deodara ◽  
Developmental Threshold ◽  
Factors Affecting ◽  
Rate Of Increase ◽  
Influence Of Temperature On ◽  
Development Duration

Abstract Temperature is one of the main factors affecting insect growth, development and reproduction. The effects of temperatures (10, 15, 20, 25 and 30°C) on the development and reproduction of Cinara cedri Mimeur (Hemiptera: Aphidoidea: Lachnidae) fed on Cedrus deodara (Roxb.) G. Don were evaluated in this study. With the increase of temperature from 10 to 30°C, the development duration at different development stages gradually shortened. There was a significant positive correlation between the developmental rates and temperature, following a quadratic regression model. The lower developmental threshold temperature (C) and effective accumulated temperatures (K) for completing a generation were 4.13°C and 263.4 degree-days, respectively. The highest fecundity was observed at 20°C with 25.74 first-instar nymphs/female. Both the highest intrinsic rate of increase (r, 0.11 ± 0.03) and net reproduction rate (R0, 19.06 ± 2.05) were observed at 20°C, whereas the lowest values of r (0.05 ± 0.01) at 10°C and R0 (5.78 ± 0.88) at 30°C were observed. The results suggest that temperature significantly affects the biology of C. cedri and the optimal temperature for its development is 20°C.

Ambient Humidity Affects Development, Survival, and Reproduction of the Invasive Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), in China

2021 ◽  
Author(s):  
Limei He ◽  
Shengyuan Zhao ◽  
Abid Ali ◽  
Shishuai Ge ◽  
Kongming Wu
Keyword(s):  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Reproduction Rate ◽  
Ambient Humidity ◽  
Rate Of Increase ◽  
Population Forecasting ◽  
Survival And Reproduction ◽  
Net Reproduction

Abstract Ambient humidity can directly affect the water balance in insects. The migratory fall armyworm, Spodoptera frugiperda Smith, has spread to more than 60 countries and regions in Africa, Asia, and Oceania that have a great difference in average ambient humidity. Understanding the effects of ambient humidity changes on its development, survival, and reproduction can help to predict its population dynamics in different habitats. Therefore, we evaluated the effects of atmospheric relative humidity (RH) on the development, survival, and reproduction and soil moisture on the pupation and emergence of fall armyworm. As a result, survival and pupal mass increased significantly with increasing RH. Among the five RHs tested, 80% RH was the most suitable for fall armyworm with the highest intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R0). The population growth at the different RHs in decreasing order was 80 > 100 > 60 > 40 > 20%. A relative moisture (RM) of soil from 6.80 to 47.59% was suitable for fall armyworm pupation, survival, and eclosion, but fall armyworm could not pupate normally in soil with 88.39 and 95.19% RM. The survival and emergence rate of fall armyworm pupae were reduced by irrigation that increased the RM after the mature larvae entered the soil. These findings may be helpful for refining laboratory rearing protocols, population forecasting, and management of fall armyworm.

scholarly journals Repeated stress exposure results in a survival–reproduction trade-off in Drosophila melanogaster

2009 ◽  
Vol 277 (1683) ◽  
pp. 963-969 ◽  
Author(s):  
Katie E. Marshall ◽  
Brent J. Sinclair
Keyword(s):  
Drosophila Melanogaster ◽  
Model Organism ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Stress Exposure ◽  
Trade Off ◽  
Repeated Stress ◽  
Rate Of Increase ◽  
In The Wild ◽  
Future Reproduction

While insect cold tolerance has been well studied, the vast majority of work has focused on the effects of a single cold exposure. However, many abiotic environmental stresses, including temperature, fluctuate within an organism's lifespan. Given that organisms may trade-off survival at the cost of future reproduction, we investigated the effects of multiple cold exposures on survival and fertility in the model organism Drosophila melanogaster . We found that multiple cold exposures significantly decreased mortality compared with the same length of exposure in a single sustained bout, but significantly decreased fecundity (as measured by r , the intrinsic rate of increase) as well, owing to a shift in sex ratio. This change was reflected in a long-term decrease in glycogen stores in multiply exposed flies, while a brief effect on triglyceride stores was observed, suggesting flies are reallocating energy stores. Given that many environments are not static, this trade-off indicates that investigating the effects of repeated stress exposure is important for understanding and predicting physiological responses in the wild.

scholarly journals Hosts of Raoiella indica Hirst (Acari: Tenuipalpidae) Native to the Brazilian Amazon

2017 ◽  
Vol 9 (4) ◽  
pp. 86 ◽  
Author(s):  
Cristina A. Gómez-Moya ◽  
Talita P. S. Lima ◽  
Elisângela G. F. Morais ◽  
Manoel G. C. Gondim Jr. ◽  
Gilberto J. De Moraes
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Brazilian Amazon ◽  
Intrinsic Rate Of Increase ◽  
Native Plant ◽  
Instantaneous Rate ◽  
Net Reproductive Rate ◽  
Musa Paradisiaca ◽  
Rate Of Increase ◽  
Raoiella Indica

The expansion of red palm mite (RPM), Raoiella indica (Acari: Tenuipalpidae) in Brazil could impact negatively the native plant species, especially of the family Arecaceae. To determine which species could be at risk, we investigated the development and reproductive potential of R. indica on 19 plant species including 13 native species to the Brazilian Amazon (12 Arecaceae and one Heliconiaceae), and six exotic species, four Arecaceae, a Musaceae and a Zingiberaceae. Values of the instantaneous rate of increase (ri) were initially estimated at 7, 14, 21 and 28 days after infestation of each species. Higher values of ri (> 0.05) were determined on the Arecaceae Adonidia merrillii, Astrocaryum jauari, Cocos nucifera, Bactris simplicifrons, Mauritia flexuosa, Phoenix dactylifera and Socratea exorrhiza, and on the Heliconiaceae Heliconia psittacorum Sassy; these were classified as “potential primary hosts”. Lower, but still positive values of ri (0-0.05) were determined on the Arecaceae Bactris maraja, Oenocarpus bacaba, Oenocarpus bataua and on the Musaceae Musa × paradisiaca (Prata variety); these were classified as “potential secondary hosts”. Negative values of ri were determined for the remaining plants, i.e., the Arecaceae Astrocaryum aculeatum, Attalea maripa, Bactris gasipaes, Elaeis guineensis, Euterpe oleracea, Euterpe precatoria, and the Zingiberaceae Alpinia rosea; these were considered “non-hosts”. Species with ri < 0.05 were considered not to be threatened by the RPM. Biological parameters of RPM were evaluated on the plant species with positive ri (except B. maraja) and two native species with negative ri (E. oleracea and E. precatoria). Mean developmental time ranged from 14.7 days on C. nucifera to 21.4 days on Musa × paradisiaca, showing a significant influence of the plant substrate. Immature viability, oviposition rate, net reproductive rate (R0) and intrinsic rate of increase (rm) were affected by the plant species.

scholarly journals Life history of Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae) fed with castor bean (Ricinus communisL.) pollen in laboratory conditions

2014 ◽  
Vol 74 (3) ◽  
pp. 691-697 ◽  
Author(s):  
PP Marafeli ◽  
PR Reis ◽  
EC. da Silveira ◽  
GC Souza-Pimentel ◽  
MA. de Toledo
Keyword(s):  
Life History ◽  
Castor Bean ◽  
Ricinus Communis ◽  
Intrinsic Rate ◽  
Predatory Mite ◽  
Neoseiulus Californicus ◽  
Intrinsic Rate Of Increase ◽  
Ricinus Communis L ◽  
Rate Of Increase ◽  
History Of

The predatory mite, Neoseiulus californicus(McGregor, 1954) (Acari: Phytoseiidae) is one of the principal natural enemies of tetranychid mites in several countries, promoting efficient control of those mites in several food and ornamental crops. Pest attacks such as that of the spider mite, Tetranychus urticaeKoch, 1836 (Acari: Tetranychidae), is one of the problems faced by farmers, especially in the greenhouse, due to the difficulty of its control with the use of chemicals because of the development of fast resistance making it hard to control it. The objective of this work was to study the life history of the predatory mite N. californicus as a contribution to its mass laboratory rearing, having castor bean plant [Ricinus communis L. (Euphorbiaceae)] pollen as food, for its subsequent use as a natural enemy of T. urticae on a cultivation of greenhouse rosebushes. The studies were carried out in the laboratory, at 25 ± 2°C of temperature, 70 ± 10% RH and a 14 hour photophase. The biological aspects and the fertility life table were appraised. Longevity of 32.9 days was verified for adult females and 40.4 days for males. The intrinsic rate of increase (rm) was 0.2 and the mean generation time (T) was 17.2 days. The population doubled every 4.1 days. The results obtained were similar to those in which the predatory mite N. californicus fed on T. urticae.

Reproductive Uncertainty and the Evolution of Iteroparity: Why Don't Flatfish Put All Their Eggs in One Basket?

1981 ◽  
Vol 38 (8) ◽  
pp. 968-977 ◽  
Author(s):  
Derek A. Roff
Keyword(s):  
Reproductive Success ◽  
Life Span ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Rate Of Increase ◽  
Age Of Maturity ◽  
Reproductive Life ◽  
Reproductive Life Span ◽  
Engraulis Ringens ◽  
Using Data

Murphy's hypothesis that variation in reproductive life span is an adaptive response to variation in the predictability of reproductive success is examined. Murphy's contention that this hypothesis explains the variation in reproductive life span within the clupeids is reexamined incorporating further data on the Peruvian anchovy (Engraulis ringens). A nonsignificant correlation is now obtained between reproductive life span and brood strength variation; thus, the hypothesis is called into question. An alternative explanation is presented that considers the interaction between life history parameters: because it is necessary for the intrinsic rate of increase to exceed zero, variation in one parameter must be associated with variation in at least one other parameter. In the clupeids it is noted that the age of maturity and reproductive life span vary in concert and it is suggested that this provides an explanation of variation in reproductive life span. These two hypotheses are examined using data on the family Pleuronectidae, the flatfish. No correlation exists between reproductive life span and the degree of fluctuation in brood strength but there is a significant correlation between reproductive life span and age of maturity. It is concluded that variation in reproductive life span within the flatfish group is not a response to variation in reproductive success but rather a correlate of variation in age of maturity.Key words: flatfish, Pleuronectidae, iteroparity, natural selection, reproduction, clupeids

scholarly journals Biology and life-table of Typhlodromus (Anthoseius) athenas (Acari: Phytoseiidae) fed with the Old World Date Mite, Oligonychus afrasiaticus (Acari: Tetranychidae)

Acarologia ◽  
2018 ◽  
Vol 58 (1) ◽  
pp. 52-61
Author(s):  
Samah Ben Chaaban ◽  
Brahim Chermiti ◽  
Serge Kreiter
Keyword(s):  
Life Table ◽  
Intrinsic Rate ◽  
Phoenix Dactylifera ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Old World ◽  
Rate Of Increase ◽  
Wide Range ◽  
The Mean

The old world date mite Oligonychus afrasiaticus is an important spider mite pest of the date palms Phoenix dactylifera L. mostly in North Africa and the Middle East. A population of the predaceous mite Typhlodromus (Anthoseius) athenas has been recently found in Tunisia in association with a decrease of O. afrasiaticus densities. The objective of this paper was to assess the development and reproduction abilities of T. ( A.) athenas on O. afrasiaticus under laboratory conditions at two temperatures: 27 and 32 °C. The results obtained show that females of T. (A.) athenas develop in 5 days at 27 °C and 4.1 days at 32 °C. The mean fecundity of T. (A.) athenas was 32.1 and 23.2 eggs per female at 27 and 32 °C, respectively. Life table parameters were stimated: the net reproductive rate (Ro) 27.9 and 17.9 eggs/female, the intrinsic rate of increase (rm) 0.322 and 0,344 female/female/day and the mean generation time (T) 10.3 and 8.4 days at 27 and 32 °C, respectively. At both temperatures tested, T. (A.) athenas intrinsic rate of increase was greater than that of O. afrasiaticus (rm = 0.213 at 32 °C,against rm = 0.166 day1 at 27 °C). Typhlodromus (A.) athenas would be able to develop at a wide range of temperatures feeding on O. afrasiaticus and seems to be able to potentially control it.

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