Bias introduced by the simplified method for the estimation of the intrinsic rate of increase of aphid populations: A meta-analysis

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.

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

Journal of Economic Entomology ◽

10.1093/jee/toab056 ◽

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.

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

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2009.1807 ◽

2009 ◽

Vol 277 (1683) ◽

pp. 963-969 ◽

Cited By ~ 135

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.

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

Brazilian Journal of Biology ◽

10.1590/bjb.2014.0079 ◽

2014 ◽

Vol 74 (3) ◽

pp. 691-697 ◽

Cited By ~ 9

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.

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

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f81-130 ◽

1981 ◽

Vol 38 (8) ◽

pp. 968-977 ◽

Cited By ~ 42

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

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

Acarologia ◽

10.24349/acarologia/20184229 ◽

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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Potential Rates of Increase of a Harbour Porpoise (Phocoena phocoena) Population Subjected to Incidental Mortality in Commercial Fisheries

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f91-284 ◽

1991 ◽

Vol 48 (12) ◽

pp. 2429-2435 ◽

Cited By ~ 35

Author(s):

Thomas H. Woodley ◽

Andrew J. Read

Keyword(s):

Gulf Of Maine ◽

Intrinsic Rate ◽

Frequency Equation ◽

Harbour Porpoise ◽

Population Increase ◽

Intrinsic Rate Of Increase ◽

Natural Mortality ◽

Phocoena Phocoena ◽

Rate Of Increase ◽

Incidental Mortality

We estimated the potential intrinsic rate of increase (r) of the harbour porpoise (Phocoena phocoena) population in the Bay of Fundy and Gulf of Maine using empirical data on reproductive rates (mx) and several hypothetical survival (Ix) schedules. Schedules of Ix, to maximum ages of 12 and 15 yr, were calculated from two potential natural mortality (nx) schedules combined with several schedules of incidental mortality (hx) estimates. The most realistic results were obtained when nx of non-calves were calculated from Caugley's (1966. Ecology 47: 906–918) smoothed age-frequency equation for Himalayan thar (Hemitragus jemlahicus) and applied in conjunction with a range of calf natural mortality estimates, this model indicates that harbour porpoises have a limited capacity for population increase, and populations are unlikely to sustain even moderate levels of incidental mortality (4% of the population per year). Extending the maximum age used in the models from 12 to 15 yr does little to increase estimates of r for the harbour porpoise population, and hence their susceptibility to incidental mortality.

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Biological responses of Tetranychus urticae to five pepper cultivars at two phenological stages of host plants

Systematic and Applied Acarology ◽

10.11158/saa.26.10.7 ◽

2021 ◽

Author(s):

Samira Khodayari ◽

Maryam Hashemian Shalilvand

Keyword(s):

Tetranychus Urticae ◽

Host Plants ◽

Intrinsic Rate ◽

Intrinsic Rate Of Increase ◽

Adult Longevity ◽

Phenological Stages ◽

Rate Of Increase ◽

Significant Difference ◽

Before And After ◽

Important Pest

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is an important pest of pepper (Capsicum annuum L.). Control of this pest is usually dependent on chemical pesticides. The use of resistant plant cultivars in conjugation with other control tactics generates more effective and long lasting results in management of many pests. In this study we used two-sex life table to evaluate the performance of T. urticae on five pepper cultivars (11983, ES4, Hashemi, Mahali and USL) before and after blooming of host plants. The results showed that the immature time, adult longevity and fecundity differed significantly among cultivars. Before blooming on 11983, the values for the intrinsic rate of increase (r) and the finite rate of increase (λ) were 0.0645 and 1.066 day-1 respectively, which were significantly the lowest; the highest r and λ values was recorded on ES4 which were 0.1347 and 1.144 day-1 respectively. After blooming there was no significant difference in these values among cultivars except for Mahali in which these values were significantly the highest (0.0751 and 1.078 day-1 respectively). Comparing between the phenological stages of host plants (before and after blooming) indicated that after blooming all of the tested pepper cultivars were more resistant to T. urticae. In summary, among the different cultivars tested, the most suitable was ES4 and the least suitable was 11983 before blooming of host plants. After blooming the suitability of host plants changed and decreased significantly.

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