SEASONAL ABUNDANCE OF THE PEA APHID, ACYRTHOSIPHON PISUM (HOMOPTERA: APHIDIDAE), IN MANITOBA FIELD PEAS

1986 ◽  
Vol 118 (6) ◽  
pp. 601-607 ◽  
Author(s):  
G.A. Maiteki ◽  
R.J. Lamb ◽  
S.T. Ali-Khan
Keyword(s):  
Pisum Sativum ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Seasonal Abundance ◽  
Economic Threshold ◽  
Field Peas ◽  
Pea Aphids

AbstractPea aphids, Acyrthosiphon pisum (Harris), were sampled from 1980 to 1983 in field peas, Pisum sativum (L.), in Manitoba. Sweep and foliage samples were taken in commercial fields and plots. Aphids were found in late May or early June soon after the crop emerged, but populations were low throughout June. Populations increased in July, when the crop was flowering and producing pods, and peaked in the latter half of July or early August in 3 of the 4 years, when pods were maturing. Populations decreased rapidly after the peak, as the plants senesced. In 1980, a drought year, aphid densities were low and the populations peaked in the middle of August. From 1981 to 1983, densities exceeded the economic threshold in all commercial fields and all but one of the plots that were sampled.

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 Influence of intercropping with spring cereals on the occurrence of pea aphids (Acyrthosiphon pisum Harris, 1776) and their natural enemies in field pea (Pisum sativum L.)

2011 ◽  
Vol 47 (No. 1) ◽  
pp. 25-36 ◽  
Author(s):  
M. Seidenglanz ◽  
I. Huňady ◽  
J. Poslušná ◽  
A.-K. Løes
Keyword(s):  
Pisum Sativum ◽  
Entomopathogenic Fungi ◽  
Natural Enemies ◽  
Acyrthosiphon Pisum ◽  
Parasitic Wasp ◽  
Aphidius Ervi ◽  
Pisum Sativum L ◽  
Field Peas ◽  
Pea Aphids ◽  
Spring Cereals

Occurrences of pea aphids and their natural enemies (syrphids, mummies caused by entomopathogenic fungi Beauveria sp. and by the parasitic wasp Aphidius ervi) were compared in monocultures and mixtures of field peas and spring cereals in three seasons (2008–2010). At the beginning of colonisation, the occurrence of aphids was not substantially influenced by intercropping with cereals. However, the numbers of pea aphids located on inflorescences started to decline earlier in mixtures compared with monoculture. More syrphids (eggs + larvae) were found in mixtures than in monoculture, and more syrphid eggs were found in young aphid colonies (10 to 20 individuals) in mixtures. Intercropping did not influence the occurrence of fungal mummies (Beauveria sp.), but mixtures tended to have more aphid colonies infested by A. ervi in 2008 and 2009.  

GROWTH OF PEA APHID, ACYRTHOSIPHON PISUM (HARRIS) (HOMOPTERA: APHIDIDAE), POPULATIONS ON CAGED PLANTS OF SIX CULTIVARS OF FIELD PEAS AND THE EFFECTS OF PEA APHIDS ON HARVEST COMPONENTS OF CAGED FIELD PEAS

1990 ◽  
Vol 122 (6) ◽  
pp. 1193-1199 ◽  
Author(s):  
J.J. Soroka ◽  
P.A. Mackay
Keyword(s):  
Acyrthosiphon Pisum ◽  
Yield Component ◽  
Lower Number ◽  
Field Pea ◽  
Pea Aphid ◽  
Field Cage ◽  
Field Peas ◽  
Pea Aphids ◽  
Made In

AbstractA comparison of the effects of infestation by known numbers of pea aphids, Acyrthosiphon pisum (Harris), on six field pea cultivars was made in field cage tests. The largest population of aphids developed on the cultivar Trapper and the smallest on the cultivar Century, with differences in aphid numbers between these cultivars significant for mature plants. Infested plants of Trapper had a significantly lower number of pods per plant, and infested plants of all cultivars had decreased seed weights, both per metre row and of 250 seeds, when compared with control plants. In all cultivars except Trapper, the most severely affected yield component was weight of 250 seeds.

SEASONAL OCCURRENCE OF THE PEA APHID, ACYRTHOSIPHON PISUM (HARRIS) (HOMOPTERA: APHIDIDAE), ON CULTIVARS OF FIELD PEAS IN MANITOBA AND ITS EFFECTS ON PEA GROWTH AND YIELD

1990 ◽  
Vol 122 (3) ◽  
pp. 503-513 ◽  
Author(s):  
J.J. Soroka ◽  
P.A. Mackay
Keyword(s):  
Seed Weight ◽  
Acyrthosiphon Pisum ◽  
Regression Line ◽  
Pea Aphid ◽  
Aphid Population ◽  
Growth And Yield ◽  
Field Peas ◽  
Aphid Feeding ◽  
One Year ◽  
Yield Responses

AbstractPopulations of pea aphid, Acyrthosiphon pisum (Harris), were sampled through the summer of 1984 on five cultivars and in 1985 and 1986 on six cultivars of field peas, Pisum sativum L., grown in field plots in southern Manitoba. Patterns of pea aphid population growth were generally similar among cultivars in any one year. Aphid populations on all cultivars in all years remained relatively low until mid-July, then increased rapidly, peaked at about the beginning of August, and declined sharply to low levels in late August. At the time of peak aphid numbers, significant differences in aphid population densities were found among cultivars in 2 years; the lowest densities were found on the cultivars Century and Tipu, and the highest densities on Triumph or Trapper. Pea aphid feeding was not detrimental to any yield parameters except 1000 seed weight. In 1984 Triumph and Tara, and in 1985 Triumph had significantly decreased 1000 seed weights in plots in which aphid densities were not controlled. Differences in the abundance of the aphid among cultivars were not reflected in their yield responses. Over 3 years the regression line of aphid densities upon Century seed weight was significantly steeper than those of Trapper, Lenca, or Tara. Trapper was least affected by aphid feeding. Results indicated that the economic threshold of pea aphids on peas other than Century needs to be re-evaluated.

INFLUENCE OF STARVATION ON DEVELOPMENT AND REPRODUCTION IN APTEROUS VIRGINOPARAE OF THE PEA APHID, ACYRTHOSIPHON PISUM (HARRIS) (HOMOPTERA: APHIDIDAE)

1992 ◽  
Vol 124 (1) ◽  
pp. 87-95 ◽  
Author(s):  
K.L. Kouamé ◽  
M. Mackauer
Keyword(s):  
Vicia Faba ◽  
Acyrthosiphon Pisum ◽  
Reproductive Investment ◽  
Dry Weight ◽  
Pea Aphid ◽  
Nutrient Loss ◽  
Adult Weight ◽  
Pea Aphids ◽  
Wet Weight ◽  
Growth Development

AbstractThe influence of nutrient stress on growth, development, and reproduction in apterous virginoparae of the pea aphid, Acyrthosiphon pisum (Harris), was investigated in the laboratory. We tested the hypothesis that species with a high reproductive investment have low resistance to starvation. Aphids in two groups were starved daily from birth for 4 h and 6 h, respectively, and compared with feeding counterparts reared on leaves of broad beans, Vicia faba L. Aphid wet weight increased as an exponential function of age in all groups. Starved aphids had lower adult weight and required longer from birth to parturition than feeding aphids. These effects increased with the length of daily starvation. The number of offspring produced was correlated with adult dry weight. Aphids were unable to compensate, or to compensate completely, for water and nutrient loss resulting from starvation. It is suggested that pea aphids allocate resources first to maintenance and then to reproduction when deprived of food.

COMPARISON OF SWEEP-NET AND STEM-COUNT TECHNIQUES FOR SAMPLING PEA APHIDS IN ALFALFA

1989 ◽  
Vol 24 (3) ◽  
pp. 344-347
Author(s):  
G. David Buntin ◽  
David J. Isenhour
Keyword(s):  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Density Estimates ◽  
Pea Aphids ◽  
Efficient Alternative ◽  
Highly Correlated ◽  
Sweep Net

The accuracy, precision and efficiency of stem-count and sweep-net techniques were compared for sampling the pea aphid, Acyrthosiphon pisum (Harris), in alfalfa. Density estimates by both techniques were highly correlated (r = 0.87). Both techniques were similar in sample precision and efficiency, but stem counts provided more accurate density estimates than the sweep net technique. The stem count technique is an accurate and efficient alternative to the sweep net for sampling pea aphids in alfalfa.

Escape behaviour of the pea aphid Acyrthosiphon pisum (Harris) in response to alarm pheromone and vibration

1982 ◽  
Vol 60 (10) ◽  
pp. 2245-2252 ◽  
Author(s):  
J. M. Clegg ◽  
C. A. Barlow
Keyword(s):  
Host Plant ◽  
Alarm Pheromone ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Escape Behaviour ◽  
Pea Aphids ◽  
Escape Responses

Pea aphids respond most effectively to the threat of a predator by walking away or dropping from their host plant. Simulating threat by using vibration and alarm pheromone, both separately and together, we found no evidence that escape responses are heritable, nor that individual aphids have characteristic escape behaviours. On the contrary, the amount of alarm pheromone influenced responses: the more pheromone, the more likely an immediate and effective escape. Vibration preceding alarm pheromone greatly increased responsiveness to pheromone, and aphids were more responsive to pheromone after vibration when feeding on stems than when feeding on the undersides of leaves.

Pea aphid, Acyrthosiphon pisum, cornicle ontogeny as an adaptation to differential predation risk

2002 ◽  
Vol 80 (12) ◽  
pp. 2131-2136 ◽  
Author(s):  
Edward B Mondor ◽  
Bernard D Roitberg
Keyword(s):  
Alarm Pheromone ◽  
Acyrthosiphon Pisum ◽  
Harmonia Axyridis ◽  
Inclusive Fitness ◽  
Pea Aphid ◽  
Body Parts ◽  
Anatomical Structures ◽  
Alarm Signaling ◽  
Risk Of Predation ◽  
Pea Aphids

Aphids possess unique anatomical structures called cornicles through which a defensive secretion containing alarm pheromone is often emitted when a predator attacks an aphid. The levels of alarm pheromone in cornicle droplets from the pea aphid, Acyrthosiphon pisum (Harris), vary considerably during development; however, it is not clear how the length of the cornicle changes during ontogeny. The length of the cornicle relative to the lengths of other body structures may have profound effects on aphid defense and alarm signal diffusion. Using previously published morphological measurements of pea aphids and observing interactions between pea aphids and multicolored Asian ladybird beetles, Harmonia axyridis Pallas, it was observed that pea aphid cornicles elongate proportionally more than other body parts during the first four instars, when alarm-pheromone levels have peaked, than during the fifth (adult) instar, when pheromone levels decline. Pea aphids also are more likely to emit cornicle droplets and daub them onto a predator when the cornicles are undergoing such rapid growth. We suggest that because of a high risk of predation, rapid cornicle growth in juveniles has evolved both for individual defense and for the inclusive fitness benefits of alarm signaling.

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