scholarly journals Direct and Knock-on Effects of Water Stress on the Nutrient Contents ofTriticum aestivum(Poales: Poaceae) and Population Growth ofRhopalosiphum padi(Hemiptera: Aphididae)

2021 ◽  
Author(s):  
Ya-Ying Lin ◽  
Wei-Cheng Liu ◽  
Yi-Ting Hsu ◽  
Ching-Hsin Hsu ◽  
Chi-Chieh Hu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Water Stress ◽  
Population Growth ◽  
Nutrient Intake ◽  
Soluble Sugars ◽  
Winter Season ◽  
Intrinsic Rate Of Increase ◽  
Cereal Aphids ◽  
Wheat Seedlings ◽  
Rate Of Increase

AbstractTo ascertain the direct effects of water stress upon wheat plants (Triticum aestivum L.) and how these effects, in turn, influence the population growth of the bird cherry-oat aphid (Rhopalosiphum padi L.), we conducted a physiological analysis of wheat seedlings grown under three different watering regimes and subsequently determined the population parameters of the aphid using the age-stage, two-sex life table. A significantly higher content of free amino acids and soluble sugars were observed in wheat seedlings exposed to drought stress compared to seedlings that were well-watered and those that were grown under waterlogged conditions. Extended phloem salivation and stylet penetration with shorter duration of sustained ingestion from phloem was observed in an electrical penetration graph (EPG) of R. padi on drought-stressed wheat seedlings. This suggested that the aphid’s feeding activity, as well as nutrient intake, were impeded. The significantly higher percentage of essential amino acids found in wheat seedlings grown under waterlogged conditions promoted significantly higher fecundity and intrinsic rate of increase in R. padi populations compared to aphids fed on drought-treated or well-watered wheat seedlings. Our findings suggest that wheat seedling responses to water stress involve changes in sap composition that are responsible for altering the aphids’ nutrient intake and consequently affect their population growth. From a grower’s perspective, extending wheat cultivation in a rice–wheat rotation paddy field during the winter season may not be economically profitable if the fields are chronically waterlogged, since this may potentially lead to a higher infestation of cereal aphids.

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.

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. 

scholarly journals PARAMETER NERACA HAYATI DAN PERTUMBUHAN POPULASI KUTU PUTIH Phenacoccus manihoti Matile-Ferrero (HEMIPTERA: PSEUDOCOCCIDAE) PADA DUA VARIETAS UBI KAYU

2014 ◽  
Vol 14 (1) ◽  
pp. 64-70
Author(s):  
Nila Wardani ◽  
Aunu Rauf ◽  
Wayan Winasa ◽  
Sugeng Santoso
Keyword(s):  
Population Growth ◽  
Growth Parameters ◽  
Intrinsic Rate ◽  
Phenacoccus Manihoti ◽  
Intrinsic Rate Of Increase ◽  
Cassava Mealybug ◽  
Rate Of Increase ◽  
Population Growth Parameters ◽  
Cassava Varieties ◽  
Cyanide Content

ABSTRACTThe life history and population growth parameters of mealybug Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties. The development, reproduction, and population growth parameters of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties were studied in laboratory. The varieties tested were UJ-5 with high cyanide content (>100 mg per kg) dan Adira-1 with low cyanide content (27.5 mg per kg).  Our research revealed that P. manihoti performances were highly affected by cassava varieties.  Incubation period of eggs of P. manihoti were 7.93 ±  0.09 and 8.33 ± 0.11 days, nymphal development periode 12.32±0.13 and 15.67 ± 0.13 days, respectively on UJ-5 and Adira-1. Fecundity averaged 386.37 ± 5.83 on UJ-5 and 318.67±2.81 eggs on Adira-1. Intrinsic rate of increase (rm) were  0.258 ± 0.001 on UJ-5 and  0.220 ± 0.001 on Adira-1. Mean generation time (T) on UJ-5 and Adira-1 were 22.795 ± 0.050 and 25.532 ± 0.047 days, repectively. Our findings showed that variety UJ-5 was more suitable for development and population growth of the cassava mealybug.

scholarly journals Effect of foundress population density and size on reproduction and population growth of a haplodiploid mite

2020 ◽  
Vol 25 (11) ◽  
pp. 2063-2076
Author(s):  
Nuwan Weerawansha ◽  
Qiao Wang ◽  
Xiong Zhao He
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Intrinsic Rate ◽  
Adaptive Strategy ◽  
Food Competition ◽  
Intrinsic Rate Of Increase ◽  
Vegetable Crops ◽  
Rate Of Increase ◽  
Population Sizes ◽  
Pest Mite

Tetranychus ludeni Zacher (Acari: Tetranychidae) is an invasive polyphagous haplodiploid pest mite of many vegetable crops in many parts of the world. This study investigated the effects of simultaneous variations in the local foundress population density and size on the reproduction and population growth of T. ludeni. We show that negative population-density and -size dependency limited the reproduction of foundresses, where the effects of population size on population growth overweighed that of population density. We further demonstrate that ovipositing females could accelerate population growth rate (intrinsic rate of increase, rm) at higher population sizes by producing more daughters early during their lifespan, which can be an adaptive strategy to allow more daughters to complete development and disperse to reduce future food competition intensity. This study provided knowledge on population dynamics in response to foundress population density and size in general and T. ludeni population forecast and precise timing of pest management in particular.

scholarly journals Artificial Diet Influences Population Growth of the Root Maggot Bradysia impatiens (Diptera: Sciaridae)

2020 ◽  
Vol 20 (5) ◽  
Author(s):  
Yuping Gou ◽  
Peter Quandahor ◽  
Kexin Zhang ◽  
Sufan Guo ◽  
Qiangyan Zhang ◽  
...  
Keyword(s):  
Survival Rate ◽  
Population Growth ◽  
Artificial Diet ◽  
Population Expansion ◽  
Intrinsic Rate Of Increase ◽  
Artificial Diets ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Bradysia Impatiens ◽  
Root Maggot

Abstract In order to investigate the effects of artificial diets on the population growth of root maggot Bradysia impatiens, its population growth parameters were assayed on eight artificial diets (Diet 1, D2, D3, D4, D5, D6, D7, and D8). Results showed that developmental duration from egg to pupa was successfully completed on all eight artificial diets. However, the egg to pupal duration was shortest, while the survival rate of four insect stages was lowest when B. impatiens was reared on D1. When B. impatiens was reared on D7 and D8, the survival rate, female longevity, and female oviposition were higher than those reared on other diets. When B. impatiens was reared on D7, the intrinsic rate of increase (rm = 0.19/d), net reproductive rate (R0 = 39.88 offspring per individual), and finite rate of increase (λ = 1.21/d) were higher for its population growth with shorter generation time (T = 19.49 d) and doubling time (Dt = 3.67 d). The findings indicate that the D7 artificial diet is more appropriate for the biological parameters of B. impatiens and can be used an indoor breeding food for population expansion as well as further research. We propose that vitamin C supplement added to the D7 is critical for the improvement of the B. impatiens growth.

Population growth performance of Panonychus ulmi Koch (Acarina: Tetranychidae) on different fruit trees

2021 ◽  
Author(s):  
Ismail Kasap ◽  
Remzi Atlihan
Keyword(s):  
Population Growth ◽  
Host Plants ◽  
Prunus Avium ◽  
Panonychus Ulmi ◽  
Intrinsic Rate Of Increase ◽  
Pest Species ◽  
Finite Rate ◽  
Net Reproductive Rate ◽  
European Red Mite ◽  
Rate Of Increase

The European red mite, Panonychus ulmi (Acari: Tetranychidae) is an important pest species on deciduous plants in Turkey, especially on apple. In this study, development, survival, and reproduction of European red mite, P. ulmi were studied on different host plants under laboratory conditions (25±2 °C,% 60±10 RH and16:8 L:D photoperiod). Population performance of P. ulmi was obtained on its different host plants including apple (Malus communis L.), quince (Cydonia oblonga Mill.), cherry (Prunus avium L.), and sour cherry (Prunus cerasus L). The life history raw data of P. ulmi were analyzed by using the age-stage, two-sex life table. Results indicated that the highest net reproductive rate, intrinsic rate of increase, and finite rate of increase as well as the longest mean generation time, were obtained on apple cv. Starking delicious. The population projection simulated by using life tables based on the 0.025th and 0.975th bootstrap results of the finite rate of increase displayed the same trend with population growth parameters. Results suggested that apple cv. Starking Delicious was the favorable host for P. ulmi, however, there is potential for the pest to become a serious pest on other host plants tested under favorable conditions.

REPRODUCTION AND POPULATION GROWTH OF THE PEA APHID (HOMOPTERA: APHIDIDAE) UNDER LABORATORY AND FIELD CONDITIONS

1977 ◽  
Vol 109 (2) ◽  
pp. 277-284 ◽  
Author(s):  
A. Campbell ◽  
M. Mackauer
Keyword(s):  
Population Growth ◽  
Time Scale ◽  
Acyrthosiphon Pisum ◽  
Intrinsic Rate ◽  
Reproductive Period ◽  
Pea Aphid ◽  
Effect Of Temperature ◽  
Intrinsic Rate Of Increase ◽  
Rate Of Increase ◽  
Total Fecundity

AbstractThe effect of temperature on the age-specific fecundity and the survival of apterous and alate virginoparous pea aphid, Acyrthosiphon pisum (Harris), from Kamloops, B.C., was measured. Demographic statistics were estimated for 10.3°, 14.8°, 19.7°, 26.1°, and 27.8°C constant and for fluctuating field temperatures. On a 24-h-day time-scale, temperature and longevity were inversely related in both morphs; total fecundity was highest at average and low constant temperatures. On a physiological time-scale, the intrinsic rate of increase (rm) was insensitive to changes in constant temperature in the range between 10° and 20°C; temperatures above 25°C were detrimental to aphid population growth and survival. Alate virginoparae generally had a longer pre-reproductive period and achieved a lower mean total fecundity than apterae maintained under identical conditions. The usefulness of laboratory measurements for the prediction of population growth under variable field temperatures is discussed. Differences in the reproductive patterns of alate and apterous pea aphids are considered in the context of the r- and K-hypothesis of selection.

scholarly journals Effects of five different melon (Cucumis melo L.) cultivars on population growth of Aphis gossypii (Glover)

2021 ◽  
Vol 57 (No. 4) ◽  
pp. 310-317
Author(s):  
Evin Polat Akkopru ◽  
Serdal Bozkurt
Keyword(s):  
Population Growth ◽  
Pest Management ◽  
Life Table ◽  
Cucumis Melo ◽  
Growth Parameters ◽  
Aphis Gossypii ◽  
Management Program ◽  
Intrinsic Rate Of Increase ◽  
Rate Of Increase ◽  
Aphis Gossypii Glover

 In this study, population growth parameters of Aphis gossypii Glover (Hemiptera: Aphididae) on five different melons [Cucumis melo Linnaeus (Cucurbitaceae) cultivars (Balin, Çıtırex, 221 F1, Gediz, Yusufbey)], which are commonly grown in Turkey, were investigated in laboratory experiments. Life table parameters were estimated according to age-stage and two-sex life table theory. The results showed that A. gossypii developed more successfully on the Gediz cultivar due to the higher intrinsic rate of increase (0.5042 1/day), the finite rate of increase (1.6557 1/day) and the shorter mean generation time (8.161 days) than the other cultivars. Ecological pest control against aphids' use of resistance or less favourable host plant cultivars is considered one of the significant components of pest management. The findings obtained in this study can be used in the pest management program designed for the aphid.

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.

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