Economic Injury Level, Action Threshold, and a Yield-loss Model for the Pea Aphid, Acyrthosiphon pisum (Homoptera: Aphididae), on Green Peas, Pisum sativum

1986 ◽  
Vol 79 (6) ◽  
pp. 1681-1687 ◽  
Author(s):  
G. C. Yencho ◽  
L. W. Getzin ◽  
Garrell E. Lono
Keyword(s):  
Pisum Sativum ◽  
Acyrthosiphon Pisum ◽  
Yield Loss ◽  
Pea Aphid ◽  
Economic Injury Level ◽  
Loss Model ◽  
Action Threshold ◽  
Economic Injury ◽  
Green Peas

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.

A Re-Examination of Economic Injury Levels for Potato Leafhopper (Homoptera: Cicadellidae) on Soybean2

2000 ◽  
Vol 35 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Thomas E. Hunt ◽  
Leon G. Higley ◽  
Larry P. Pedigo
Keyword(s):  
United States ◽  
Curve Fitting ◽  
Yield Loss ◽  
Leaf Tissue ◽  
Economic Conditions ◽  
Potato Leafhopper ◽  
Eastern United States ◽  
Economic Injury Level ◽  
Calculation Methodology ◽  
Economic Injury

The potato leafhopper, Empoasca fabae (Harris), is an occasional pest of seedling soybean throughout the eastern United States. Economic injury levels (EIL) for E. fabae on soybean are not available for all vulnerable soybean stages, nor do they reflect current understandings of soybean response to injury or EIL calculation methodology. Damage terms were estimated for seedling soybean stages using curve-fitting techniques that consider the vulnerability of the expanding leaf tissue of seedling soybean. Yield loss for stage V1 soybean was 43.58 kg/ha/E. fabae/plant, for V2 was 20.41 kg/ha/E. fabae/plant, for V3 was 13.10 kg/ha/E. fabae/plant, and for V4 was 9.55 kg/ha/E. fabae/plant. Economic injury level matrices were developed to reflect changing economic conditions and management costs for V1 through V4 soybean. The EILs are 1.4 to 3.6 E. fabae/plant for V1 soybean, 3.0 to 7.8 E. fabae/plant for V2 soybean, 4.7 to 12.2 E. fabae/plant for V3 soybean, and 6.5 to 16.7 E. fabae/plant for V4 soybean.

scholarly journals Sequential sampling plan, yield loss components and economic thresholds for the pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae)

1969 ◽  
Vol 72 (3) ◽  
pp. 375-385
Author(s):  
Alejandro E. Segarra-Carmona ◽  
Alberto Pantoja
Keyword(s):  
Yield Loss ◽  
Negative Binomial ◽  
Control Strategies ◽  
Sequential Sampling ◽  
Weekly Schedule ◽  
Economic Injury Level ◽  
Economic Thresholds ◽  
Density Relationship ◽  
Economic Injury ◽  
Pepper Weevil

A negative binomial distribution best predicted pepper weevil spatial dispersion on pepper plants. Sequential sampling plans for economic threshold (ET) levels of 0.1 and 0.5 adult weevils per plant were developed and tested against a weekly schedule of sprayed and unsprayed check treatments in mini-plots. Weekly sprayed and 0.1 ET mini-plots had similar yield, but higher than 0.5 ET or mini-plots never sprayed. Direct cost to farmers was the same either with 0.1 ET or weekly sprays. However, insecticide applications were reduced by one-third with 0.1 ET. Fruit abortion constituted the main yield-loss component in the pepper weevil-pepper system. An empirical yield-loss vs. adult weevil population density relationship was estimated. This estimate agreed with a theoretical economic injury level of 0.01 adult per plant. Recommendations on the use of prophylactic and responsive control strategies for the pepper weevil are given.

Managing cabbage seedpod weevils (Coleoptera: Curculionidae) in canola (Brassicaceae) – are Lygus (Hemiptera: Miridae) affected?

2018 ◽  
Vol 151 (1) ◽  
pp. 85-93
Author(s):  
H.A. Cárcamo ◽  
S.B. Meers ◽  
C.E. Herle
Keyword(s):  
Insect Pest ◽  
Economic Injury Level ◽  
Action Threshold ◽  
Southern Alberta ◽  
Economic Injury ◽  
Flower Stage ◽  
Significant Yield ◽  
Cabbage Seedpod Weevil ◽  
The Impact ◽  
Early Flower

AbstractCabbage seedpod weevil (Ceutorhynchus obstrictus Marsham; Coleoptera: Curculionidae) and Lygus Hahn (Hemiptera: Miridae) species are part of the late season insect pest complex of canola (Brassica Linnaeus; Brassicacea) in the southern prairies of Canada. From 2010 to 2013, large strips in 73 commercial fields were studied in southern Alberta to validate action thresholds for cabbage seedpod weevil and assess the impact of insecticide spraying at the early flower stage for cabbage seedpod weevils on abundance of Lygus at the pod stage. Only fields planted in April accumulated the damaging populations of cabbage seedpod weevils, such that the application of an insecticide resulted in significant yield protection. The economic injury level for the cabbage seedpod weevil was calculated at 20 cabbage seedpod weevils per 10 sweeps, but an action threshold of 25–40 is recommended because sampling mainly occurs along the edge where cabbage seedpod weevils are initially concentrated. At the pod stage, Lygus were lower in strips sprayed with insecticides at the early flower stage than in those not sprayed, but the differences were not statistically significant. Furthermore, Lygus were generally below economically damaging levels in early seeded fields. Therefore, there is no benefit of spraying early seeded fields to attempt to prevent Lygus outbreaks when cabbage seedpod weevils are below thresholds because Lygus may pose a risk only in fields planted later in the season.

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