Life Table Evaluation of Chronic Exposure to a Pesticide

1981 ◽  
Vol 38 (5) ◽  
pp. 485-494 ◽  
Author(s):  
Richard E. Daniels ◽  
J. David Allan
Keyword(s):  
Population Growth ◽  
Life Table ◽  
Daphnia Pulex ◽  
Sublethal Effect ◽  
Intrinsic Rate ◽  
Growth Potential ◽  
Population Increase ◽  
Toxic Substances ◽  
Eurytemora Affinis

The copepod Eurytemora affinis and the cladoceran Daphnia pulex were cultured at sublethal concentrations of dieldrin to test the usefulness of the intrinsic rate of population increase, r, as a bioassay statistic. The 48-h LC50 for E. affinis was 23 μg/L, but population growth rate measured by the life table method was only 12% of its control value at 5 μg/L and was zero at 10 μg/L, indicating a substantial sublethal effect. In contrast, D. pulex had a higher EC50 (251 μg/L) and showed little impairment of population growth potential below 220 μg/L. We suggest that the cladoceran was less sensitive than the copepod in both short- and long-term tests because of its simpler life cycle and larger size at hatching. The life table estimate of r appears to be an ecologically realistic measure of sublethal stress and requires an equivalent or shorter time to conduct than conventional long-term tests.Key words: acute toxicity, chronic toxicity, life table, r, toxic substances, Daphnia pulex, Eurytemora affinis, pesticide, dieldrin

Plant Resistance in Some Modern Soybean Varieties May Favor Population Growth and Modify the Stylet Penetration of Bemisia tabaci (Hemiptera: Aleyrodidae)

2021 ◽  
Author(s):  
Mauricélia F Almeida ◽  
Clébson S Tavares ◽  
Euires O Araújo ◽  
Marcelo C Picanço ◽  
Eugênio E Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Bemisia Tabaci ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Genetically Engineered ◽  
Population Increase ◽  
Net Reproductive Rate ◽  
Bt Toxin ◽  
Demographic Performance

Abstract Complaints of severe damage by whiteflies in soybean fields containing genetically engineered (GE) varieties led us to investigate the role of transgenic soybean varieties expressing resistance to some insects (Cry1Ac Bt toxin) and to herbicide (glyphosate) on the population growth and feeding behavior of Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae). In the laboratory, the whiteflies reared on the GE Bt soybeans had a net reproductive rate (R0) 100% higher and intrinsic rate of population increase (rm) 15% higher than those reared on non-GE soybeans. The increased demographic performance was associated with a higher lifetime fecundity. In electrical penetration graphs, the whiteflies reared on the GE soybeans had fewer probes and spent 50% less time before reaching the phloem phase from the beginning of the first successful probe, indicating a higher risk of transmission of whitefly-borne viruses. Data from Neotropical fields showed a higher population density of B. tabaci on two soybean varieties expressing glyphosate resistance and Cry1Ac Bt toxin. These results indicate that some GE soybean varieties expressing insect and herbicide resistances can be more susceptible to whiteflies than non-GE ones or those only expressing herbicide resistance. Most likely, these differences are related to varietal features that increase host-plant susceptibility to whiteflies. Appropriate pest management may be needed to deal with whiteflies in soybean fields, especially in warm regions, and breeders may want to consider the issue when developing new soybean varieties.

scholarly journals Influence of Temperature on Age-Stage, Two-Sex Life Tables for a Minnesota-Acclimated Population of the Brown Marmorated Stink Bug (Halyomorpha halys)

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 108 ◽  
Author(s):  
Byju N. Govindan ◽  
William D. Hutchison
Keyword(s):  
Population Growth ◽  
Life Table ◽  
Growth Potential ◽  
Intrinsic Rate Of Increase ◽  
Halyomorpha Halys ◽  
Brown Marmorated Stink Bug ◽  
Stink Bug ◽  
Current Limit ◽  
Rate Of Increase ◽  
Survival And Reproduction

Temperature is a critical single factor influencing insect population dynamics, and is foundational for improving our understanding of the phenology of invasive species adapting to new agroecosystems or in the process of range expansion. An age-stage, two-sex life table was therefore developed to analyze fundamental demographic features such as development, survival, and reproduction of a Minnesota-acclimated population of the invasive brown marmorated stink bug (Halyomorpha halys), in the north central USA. All salient life history parameters were estimated to better understand the population growth potential of H. halys at the current limit of its northern range in North America. We examined the effect of selected constant temperatures on immature development and survival (15–39 °C), adult reproduction and longevity (17–36 °C) of H. halys in the laboratory. The Minnesota population developed faster and survived at higher rates relative to a population that had previously established in Pennsylvania, USA. Mean generation time for the Minnesota population was minimized at 30 °C, while survival and fecundity were maximized at 27 and 23 °C, respectively. Given these findings, we assessed the effect of temperature on the intrinsic rate of increase ( r m ), the life table parameter that integrates the effects of temperature on development, survival, and reproduction. A Ratkowsky model predicted r m was maximized (0.0899) at 27.5 °C. We discuss the implications of our findings for understanding population growth rates for H. halys in the context of a warming climate, and potential to emerge as a serious crop pest in the Midwest U.S. region.

scholarly journals Praon volucre (Hymenoptera: Braconidae: Aphidiinae), a natural enemy of Macrosiphum euphorbiae (Hemiptera: Aphididae): Life table and intrinsic rate of population increase

2011 ◽  
Vol 108 (4) ◽  
pp. 575-580 ◽  
Author(s):  
Juracy Caldeira LINS ◽  
Vanda Helena Paes BUENO ◽  
Diego Bastos SILVA ◽  
Marcus Vinicius SAMPAIO ◽  
Joop C. van LENTEREN
Keyword(s):  
Life Table ◽  
Natural Enemy ◽  
Intrinsic Rate ◽  
Macrosiphum Euphorbiae ◽  
Population Increase

Population growth of Brevipalpus lewisi McGregor (Acarina: Tenuipalpidae) on grapevines

1980 ◽  
Vol 31 (5) ◽  
pp. 957 ◽  
Author(s):  
GA Buchanan ◽  
M Bengston ◽  
EM Exley
Keyword(s):  
Relative Humidity ◽  
Population Growth ◽  
Field Study ◽  
Growth Potential ◽  
Seasonal Abundance ◽  
Population Increase ◽  
Leaf Fall ◽  
Maximum Value ◽  
Positive Population

In the Mildura district of Victoria, Brevipalpus lewisi McGregor is responsible for 'bunch mite' symptoms on grapevines. Age-specific life and fecundity tables, compiled in the laboratory, showed that B. lewisi is capable of positive population growth over a range of temperatures at relative humidity levels commonly encountered in the field. The maximum value of rm obtained in the laboratory was 0.04/day, at 28�C and 35 % relative humidity. A field study of the seasonal abundance and intra-vine distribution of B. lewisi showed that populations increased about 60-fold during a season. The rate of population increase during summer was similar to laboratory estimates of population growth potential. Although the mites were present solely at the base of canes early in the season, later all green parts of the plant became infested. Predation and loss associated with leaf fall reduced the numbers of mites overwintering. Populations were further reduced by removal of mites during pruning.

scholarly journals Population Growth Potential of the Bed Bug, Cimex lectularius L.: A Life Table Analysis

Insects ◽  
2011 ◽  
Vol 2 (2) ◽  
pp. 173-185 ◽  
Author(s):  
Andrea M. Polanco ◽  
Carlyle C. Brewster ◽  
Dini M. Miller
Keyword(s):  
Population Growth ◽  
Life Table ◽  
Growth Potential ◽  
Cimex Lectularius ◽  
Life Table Analysis ◽  
Bed Bug ◽  
Table Analysis

Patterns of Population Movement and Long-Term Population Growth in Southwestern Colorado

1988 ◽  
Vol 53 (4) ◽  
pp. 773-793 ◽  
Author(s):  
Sarah H. Schlanger
Keyword(s):  
Population Growth ◽  
Local Level ◽  
Climatic Conditions ◽  
Population Increase ◽  
Population Movement ◽  
Water Control ◽  
Short Term ◽  
Population Movements ◽  
History Of

In spite of considerable fluctuations in the likelihood of agricultural success from place to place and from time to time, the southern Colorado Plateaus show a smooth increase in farming populations between A.D. 1 and 1150. At the local level, however, population curves in this region often register a pattern of short-lived occupations and abandonments that are tied to specific patterns of short-term and long-term climatic conditions. The prehistoric population record from the Dolores area, in the southwestern corner of Colorado, demonstrates how localized population adjustments to climatically sensitive environments can result in long-term population increases. Here, a 600-year history of population increase was maintained primarily through population movements between environmentally complementary places. When that strategy failed, due to a combination of adverse short-term and long-term climatic conditions, agricultural methods shifted from rainfall farming to intensified agriculture supported by water-control facilities.

Population growth of a copepod Gladioferens imparipes Thomson

1974 ◽  
Vol 25 (3) ◽  
pp. 351 ◽  
Author(s):  
RJ Rippingale ◽  
EP Hodgkin
Keyword(s):  
Population Growth ◽  
Field Data ◽  
Intrinsic Rate ◽  
Growth Potential ◽  
Intrinsic Rate Of Increase ◽  
Growth Equation ◽  
Animal Population ◽  
Rate Of Increase ◽  
High Population Growth ◽  
Maturation Rate

The intrinsic rate of increase of an animal population can be calculated from data on longevity, sex ratio, maturation rate and fecundity and can be expressed as r in the population growth equation Nt = N0ert. Laboratory and field data are used to calculate the value of r per day for the copepod Gladioferens imparipes Thomson. The r values obtained, 0.146 per day at 15� C and 0.293 per day at 25� C, are both high. This high population growth potential is interpreted as an adaptation to the estuarine habitat.

Fertility life table and biology of Tetrastichus giffardianus (Hymenoptera: Eulophidae) in the larvae of Ceratitis capitata (Diptera: Tephritidae)

2020 ◽  
pp. 1-8
Author(s):  
Elania Clementino Fernandes ◽  
Mariana Macedo Souza ◽  
Dori Edson Nava ◽  
Janisete Gomes Silva ◽  
Elton Lucio Araujo
Keyword(s):  
Life Table ◽  
Ceratitis Capitata ◽  
Intrinsic Rate ◽  
Mass Rearing ◽  
Population Increase ◽  
Intrinsic Rate Of Increase ◽  
Rate Of Increase ◽  
Males And Females ◽  
The Mean ◽  
Time Required

Abstract Tetrastichus giffardianus is a gregarious koinobiont endoparasitoid of tephritids, including Ceratitis capitata, which is one of the most important fruit pests worldwide. The objective of this study was to evaluate the effect of constant temperatures on the biology and development of the egg-adult period of T. giffardianus in larvae/pupae of C. capitata to construct a fertility life table. The study was carried out in climatic chambers at constant temperatures of 15, 20, 25, 30, and 35 ± 1°C, 70 ± 10% relative humidity and a photophase of 12 h. Complete egg and larval development occurred only at temperatures of 20, 25, and 30°C. The mean longevity of males and females was inversely proportional to temperature. The time of development of the pre-imaginal period was influenced by temperature and ranged from 41 days at 20°C to 11 days at 25°C. The best T. giffardianus performance occurred at 25°C when the intrinsic rate of increase was 0.21, the mean generation time was 20.43 days, the time required to double the population was 3.33 days, and the finite rate of population increase (λ) was 1.23. The results of this study provided information for the establishment of mass rearing and an evaluation of the adaptability of T. giffardianus to different environments, which is necessary for the use of this parasitoid in the biological control of tephritid pests, particularly C. capitata.

Asplanchna-kairomone induces life history shifts in Brachionus angularis (Rotifera)

2018 ◽  
Vol 54 ◽  
pp. 13 ◽  
Author(s):  
Ling Pan ◽  
Yi-Long Xi ◽  
Jing Gu ◽  
Shan Jiang ◽  
Han Zhu ◽  
...  
Keyword(s):  
Population Growth ◽  
Egg Production ◽  
Scenedesmus Obliquus ◽  
Intrinsic Rate ◽  
Population Increase ◽  
Food Level ◽  
Reproduction Rate ◽  
Inducible Defenses ◽  
Rapid Population Growth ◽  
Sexual Offspring

Predator-derived kairomones play an important role in ecological and evolutionary processes that enable the prey to survive predation pressure. In the presence of predatory Asplanchna, some Brachionus and Keratella species develop morphological and behavioral defenses, but whether rapid population growth and diapause are inducible defenses largely remains unknown. In the present study, parental B. angularis females cultured at 1.0 × 106 and 2.0 × 106 cells · mL−1 of Scenedesmus obliquus were indirectly exposed to 0, 40, 80 and 160 ind. L−1 of A. brightwelli using mesh enclosure, and their life-table demographic parameters, population growth rates and morphological characters were calculated and measured. The results showed that Asplanchna-released kairomone decreased significantly average lifespan, life expectancy at hatching, generation time and net reproduction rate, but increased the proportion of sexual offspring of parental B. angularis females. The threshold Asplanchna density required for significant effects varied with food level. Kairomone released by Asplanchna at 80 ind. L−1 increased significantly the intrinsic rate of population increase of B. angularis cultured at 2.0 × 106 cells · mL−1 of S. obliquus, which would offset the mortality of exposed females from predation. The accumulation of kairomone in aquatic environments enhanced the indirect effect of Asplanchna on the population growth of B. angularis. The present results indicated that rapid population growth of B. angularis induced by Asplanchna kairomone might facilitate the coexistence of preys with predators, and higher proportion of sexual offspring and then resting egg production might help the preys avoid the predator in time instead of facing the enemy through defenses.

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