MULTITROPHIC MODELS OF PREDATOR–PREY ENERGETICS: III. A CASE STUDY IN AN ALFALFA ECOSYSTEM

1984 ◽  
Vol 116 (7) ◽  
pp. 950-963 ◽  
Author(s):  
A. P. Gutierrez ◽  
J. U. Baumgaertner ◽  
C. G. Summers
Keyword(s):  
Population Dynamics ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Predator Prey ◽  
Pool Model ◽  
Metabolic Pool ◽  
Species Specific ◽  
Hypera Brunneipennis ◽  
Aphid Populations

AbstractThe field population dynamics of pea aphid (Acyrthosiphon pisum) and blue alfalfa aphid (A. kondoi) in alfalfa (Medicago sativa), as influenced by weather, competitors (Egyptian alfalfa weevil = EAW, Hypera brunneipennis), predation from coccinellids (Hippodamia convergens) and harvesting practices, are examined with a stochastic multitrophic level simulation model. The model incorporates a demand-driven functional-response model to estimate prey consumption, and a metabolic pool model to determine the rates and priorities of food allocation to respiration, growth, reproduction, and egestion.The model results compare favorably with field data, and are used to examine the effects of removal of each of the above factors on the dynamics of the aphids. The model shows that the observed density of EAW did not affect the aphid dynamics, but did reduce the standing crop of alfalfa. The predator H. convergens had a significant effect on the population dynamics of the aphids and the plant. Harvesting greatly affected the aphid population dynamics, as well as the dynamics of plant growth and reserve accumulation. However, high temperatures mediated through species-specific respiration costs and possibly a fungal pathogen were responsible for the observed dominance of blue aphid populations in the cool parts of the year and pea aphid populations during warmer parts of the year.

scholarly journals MULTITROPHIC MODELS OF PREDATOR–PREY ENERGETICS: I. AGE-SPECIFIC ENERGETICS MODELS—PEA APHID ACYRTHOSIPHON PISUM (HOMOPTERA: APHIDIDAE) AS AN EXAMPLE

1984 ◽  
Vol 116 (7) ◽  
pp. 923-932 ◽  
Author(s):  
A. P. Gutierrez ◽  
J. U. Baumgaertner ◽  
C. G. Summers
Keyword(s):  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Data Sets ◽  
Temperature Dependent ◽  
Predator Prey ◽  
Dependent Rate ◽  
Current State ◽  
Pea Aphids ◽  
Pool Model ◽  
Metabolic Pool

AbstractA simple age-specific energetics (calories or biomass) model for the growth and development, reproduction, respiration, ageing, and intrinsic survivorship as a function of temperature and per capita energy availability for pea aphid (Acyrthosiphon pisum (Harris)) is reported. The ratio of energy supply–demand is used to scale all of the rates in the model. The maximum demand for energy based upon current state values is used to drive the Frazer–Gilbert functional response model (i.e. food acquisition), which is a component of the metabolic pool model used to assimilate energy to growth, reproduction, respiration, and egestion. The extensive data sets on pea aphid energetics published by Randolph et al. (1975) were used to develop the model. As the model estimates reproduction (Mx) and survivorship (Lx) values, extensive published age-specific life-data sets on pea aphids are used to test it. The results suggest:(1) the lower thermal threshold for development is raised and the upper threshold is lowered as food resources are decreased(2) the temperature-dependent rate of development is slowed with decreasing energy resources(3) the size of individuals and reproduction become smaller as temperature approaches the upper and lower thermal thresholds.A simple model for multitrophic level interactions incorporating the acquisition and assimilation functions is presented.

scholarly journals Seasonal dynamics and entomophthoralean infection of the pea aphid, Acyrthosiphon pisum Harris

2001 ◽  
Vol 37 (No. 1) ◽  
pp. 17-24 ◽  
Author(s):  
Ľ. Cagáň ◽  
M. Barta
Keyword(s):  
Entomopathogenic Fungi ◽  
Seasonal Dynamics ◽  
Positive Relationship ◽  
Acyrthosiphon Pisum ◽  
Correlation Coefficients ◽  
Pea Aphid ◽  
Infestation Level ◽  
Erynia Neoaphidis ◽  
Growing Seasons ◽  
Aphid Populations

The seasonal dynamics of the pea aphid, Acyrthosiphon pisum Harris, and entomopathogenic fungi from the order Entomophthorales attacking the aphid were analysed in alfalfa and field pea crops during the growing seasons of 1998 and 1999 at Nitra-Malanta. In both years, pea aphid populations on pea showed a pattern with one peak, culminated at flowering and pod formation. The infestation level on alfalfa was low in both years. Entomopathogenic fungi attacking the pea aphid were identified as Erynia neoaphidis Remaudičre and Hennebert and Conidiobolus obscurus (Hall and Dunn) Remaudičre and Keller. Both pathogens infected the aphid on pea, but only E. neoaphidis was found in the alfalfa plots. Infected aphids were not found on alfalfa during 1999. The maximum levels of infected aphids on pea were 10.30% and 48.39% in 1998 and 1999, respectively. During both years alate aphids were more frequently attacked than apteral ones. Correlation coefficients indicated a positive relationship between the number of infected aphids and precipitation, but this relationship was weak or moderately strong. A strong correlation was found between the number of dead aphids and number of alate aphids counted 5 to 10 days earlier.

scholarly journals THE PHENOLOGY AND DISTRIBUTION OF APHIDS IN CALIFORNIA ALFALFA AS MODIFIED BY LADYBIRD BEETLE PREDATION (COLEOPTERA: COCCINELLIDAE)

1980 ◽  
Vol 112 (5) ◽  
pp. 489-495 ◽  
Author(s):  
A. P. Gutierrez ◽  
C. G. Summers ◽  
J. Baumgaertner
Keyword(s):  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Hippodamia Convergens ◽  
Ladybird Beetle ◽  
Distribution Parameters ◽  
Aphid Populations

AbstractThe phenologies and distributions of pea aphid (Acyrthosiphon pisum (Harris)), blue alfalfa aphid (A. kondoi (Shinji)), and spotted alfalfa aphid (Therioaphis maculata (Buckton)) were intensively studied in California alfalfa. The results showed, as expected, that aphid populations across all densities were aggregated; but that ladybird beetle (Hippodamia convergens (G.-M.)) predation increased the degree of aggregation. The distribution parameters of the aphids were estimated using methods developed by Iwao and Kuno (1971).

scholarly journals Selection following Gene Duplication Shapes Recent Genome Evolution in the Pea Aphid Acyrthosiphon pisum

2020 ◽  
Vol 37 (9) ◽  
pp. 2601-2615 ◽  
Author(s):  
Rosa Fernández ◽  
Marina Marcet-Houben ◽  
Fabrice Legeai ◽  
Gautier Richard ◽  
Stéphanie Robin ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Acyrthosiphon Pisum ◽  
High Capacity ◽  
Chromatin Accessibility ◽  
Pea Aphid ◽  
Specific Gene ◽  
Gene Duplications ◽  
Evolutionary Mechanisms ◽  
Ancestral Gene ◽  
Species Specific

Abstract Ecology of insects is as wide as their diversity, which reflects their high capacity of adaptation in most of the environments of our planet. Aphids, with over 4,000 species, have developed a series of adaptations including a high phenotypic plasticity and the ability to feed on the phloem sap of plants, which is enriched in sugars derived from photosynthesis. Recent analyses of aphid genomes have indicated a high level of shared ancestral gene duplications that might represent a basis for genetic innovation and broad adaptations. In addition, there are a large number of recent, species-specific gene duplications whose role in adaptation remains poorly understood. Here, we tested whether duplicates specific to the pea aphid Acyrthosiphon pisum are related to genomic innovation by combining comparative genomics, transcriptomics, and chromatin accessibility analyses. Consistent with large levels of neofunctionalization, we found that most of the recent pairs of gene duplicates evolved asymmetrically, showing divergent patterns of positive selection and gene expression. Genes under selection involved a plethora of biological functions, suggesting that neofunctionalization and tissue specificity, among other evolutionary mechanisms, have orchestrated the evolution of recent paralogs in the pea aphid and may have facilitated host–symbiont cooperation. Our comprehensive phylogenomics analysis allowed us to tackle the history of duplicated genes to pave the road toward understanding the role of gene duplication in ecological adaptation.

SPECIES COMPOSITION OF PEA APHID (HOMOPTERA: APHIDIDAE) PRIMARY AND SECONDARY PARASITOIDS IN WISCONSIN

1987 ◽  
Vol 119 (11) ◽  
pp. 1055-1057 ◽  
Author(s):  
R.L. Thiboldeaux ◽  
W.D. Hutchison ◽  
D.B. Hogg
Keyword(s):  
Population Dynamics ◽  
Species Composition ◽  
Population Growth ◽  
Medicago Sativa ◽  
Natural Enemies ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Important Pest ◽  
Exponential Population Growth ◽  
Exponential Population

The pea aphid, Acyrthosiphon pisum (Harris), is an important pest of alfalfa, Medicago sativa L., in Wisconsin because of its characteristic potential for exponential population growth (Hutchison and Hogg 1984, 1985) and the subsequent damage in both hay quality and quantity inflicted by high populations (Cuperus et al. 1982). In Wisconsin, as in most alfalfa-producing states, there is a vast complex of natural enemies (Hutchison and Hogg 1985) that influence pea aphid population dynamics, including the hymenopteran primary parasitoids from the Aphidiidae. These primary species, however, are also attacked by several secondary parasitoids from the families Megaspilidae, Pteromalidae, and Alloxystidae.

POPULATION GROWTH OF THE PEA APHID, ACYRTHOSIPHON PISUM (HARRIS) (HOMOPTERA: APHIDIDAE), AND PLANT RESPONSE TO APHID NUMBERS IN COMMERCIALLY GROWN FIELD PEAS IN MANITOBA

1990 ◽  
Vol 122 (6) ◽  
pp. 1201-1210 ◽  
Author(s):  
J.J. Soroka ◽  
P.A. Mackay
Keyword(s):  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Economic Thresholds ◽  
Field Peas ◽  
Aphid Control ◽  
Pea Aphids ◽  
Significant Yield ◽  
Unsprayed Plot ◽  
Plant Stem ◽  
Aphid Populations

AbstractPea aphids, Acyrthosiphon pisum (Harris), were sampled weekly or biweekly over the summers of 1985 and 1986 in a total of 15 commercial plantings of Century, Trapper, or Triumph field peas across Manitoba. Pea aphid populations rose more quickly in fields of Trapper than in Century or Triumph fields. The owners of all Trapper fields sampled initiated aerial application of insecticide for pea aphid control; at the time of spraying in 1985, plants in Trapper fields had significantly greater numbers of aphids in sweep samples than such samples from Century or Triumph fields. In 1986, Triumph plants supported greater numbers of aphids than Century or Trapper plants. Triumph plants remained green longer than plants of the other cultivais; in 1985 pea aphid numbers on this cultivar were highest on the last date sampled.Yield components were measured in sprayed and unsprayed plots within the commercial fields. When data were averaged for each cultivar, there were no significant differences in yield per area or in 1000 seed weight between sprayed and unsprayed plots. Data indicated that existing economic thresholds are too low for Trapper peas. However, one of the fields of Trapper peas that we sampled had significantly reduced numbers of pods per plant, yield per square metre, and weight of 1000 seeds in the unsprayed plot; this field had the largest population of pea aphids of any field sampled, with aphid numbers peaking at 48.5 ± 9.2 (SE) per plant lip during pod formation and filling. Significant yield losses also occurred in unsprayed plots of a Triumph field, which had a peak aphid population of 4.8 ± 1.6 per plant stem at pod maturation.

scholarly journals Population Dynamics and Yield Loss Assessment for Pea Aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on Lentil in Morocco

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1080
Author(s):  
Karim El Fakhouri ◽  
Abdelhadi Sabraoui ◽  
Zakaria Kehel ◽  
Mustapha El Bouhssini
Keyword(s):  
Population Dynamics ◽  
Acyrthosiphon Pisum ◽  
Insect Pest ◽  
Pea Aphid ◽  
Aphid Population ◽  
Maximum Temperature ◽  
Loss Assessment ◽  
Weather Factors ◽  
Management Options ◽  
Aphid Infestation

Pea aphid (Acyrthosiphon pisum Harris) is the major insect pest of lentil in Morocco. We investigated pea aphid mean numbers and yield losses on three lentil varieties at one location during three successive cropping seasons during 2015–2018. The effects of several weather factors on pea aphid population dynamics were investigated. Population density increased in early spring followed by several peaks during March–April and then steeply declined during the late spring. Aphid populations peaked at different times during the three years of the study. In 2016, higher populations occurred during the second and third weeks of April for Abda and Zaria varieties with averages of 27 and 28 aphids/20 twigs, respectively. In 2017, higher populations occurred on the 12th and 13th standard meteorological weeks (SMWs) for Zaria with averages of 24.7 and 27.03 aphids/20 twigs, respectively. In 2018, the population peaked for all varieties at three different times, 11th, 13th, and 17th SMW, with the highest for Zaria being 26.00, 47.41, and 32.33 aphids/20 twigs. Pea aphid population dynamics changed with weather conditions. The number of aphids significantly and positively correlated with maximum temperature, but significantly negatively correlated with relative humidity and wind speed. The minimum temperature and rainfall had non-significant correlations. Pea aphid infestation resulted in losses of total seed weight for all lentil varieties, with the highest avoidable losses for Bakria being 12.51% followed by Zaria with 7.72% and Abda with 4.56%. These losses may justify the development of integrated management options for control of this pest.

Aphid (Homoptera: Aphididae) Management in Alfalfa by Spring Grazing with Cattle

1997 ◽  
Vol 32 (3) ◽  
pp. 332-341 ◽  
Author(s):  
G. D. Buntin ◽  
J. H. Bouton
Keyword(s):  
Acyrthosiphon Pisum ◽  
Harmonia Axyridis ◽  
Coccinella Septempunctata ◽  
Growth Cycle ◽  
Pea Aphid ◽  
Early Application ◽  
Large Plot ◽  
Small Plot ◽  
Harmonia Axyridis Pallas ◽  
Aphid Populations

The effect of continuous, intensive grazing by cattle on aphid populations was examined in the first growth cycle of ‘Alfagraze’ and ‘Apollo’ alfalfa which are tolerant and not tolerant to grazing, respectively. Populations were almost entirely pea aphid, Acyrthosiphon pisum (Harris). The effect of grazing on aphid populations was examined in small plot exclusion studies in 1991 and 1992, and the effects of grazing and use of an early insecticide application with ≤7 day grazing restriction were examined in large plot exclusion trials in 1993 and 1994. Grazing reduced aphid populations by 66% to 90% when numbers exceeded ~1 aphid per stem. Populations were not significantly reduced by grazing when numbers did not exceed 1 per stem. Permethrin reduced aphid numbers for up to 7 wks and was more effective than carbofuran. Effects of grazing were similar regardless of insecticide usage. Coccinellid beetle populations in 1993 and 1994 were composed of Coccinella septempunctata L., Harmonia axyridis (Pallas), and Coleomegilla maculata DeGeer. Coccinellid numbers were much lower in grazed than ungrazed plots when aphid numbers were reduced by grazing in 1993, but were not greatly affected by grazing in 1994 when aphid numbers were low. Coccinellid numbers paralleled trends in aphid numbers. Continuous, intensive grazing or the early application of an insecticide at a low rate followed by grazing were effective approaches for suppressing pea aphid in alfalfa.

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