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.

scholarly journals Establishing Defoliation Thresholds for Insect Pest of Peanut in Mississippi

2019 ◽  
Vol 46 (1) ◽  
pp. 1-7 ◽  
Author(s):  
C. C. Abbott ◽  
J. M. Sarver ◽  
J. Gore ◽  
D. Cook ◽  
A. Catchot ◽  
...  
Keyword(s):  
Photosynthetic Capacity ◽  
Plant Biomass ◽  
Insect Pest ◽  
Canopy Height ◽  
Growth Stages ◽  
Economic Injury Level ◽  
Pod Yield ◽  
Economic Injury ◽  
Plant Emergence ◽  
The Impact

ABSTRACT Defoliation of peanut by foliage-feeding insects reduces photosynthetic capacity, and in turn, may reduce pod yield, particularly when canopy loss occurs at critical growth stages, i.e., 40 or 80 d after full plant emergence (DAE). The objective of this research was to determine the impact of peanut defoliation levels of 0, 20, 40, 60, 80, and 100%, at 40 or 80 DAE on canopy height and width, plant biomass, pod grade and yield, and economic injury level. Research was conducted in Stoneville and Starkville MS in 2015 and 2016. The experimental design was a six (defoliation level) by two (defoliation timing) factorial arranged in a randomized complete block. Up to four wk after defoliation, canopy height, canopy width, and plant biomass were negatively correlated with defoliation level regardless of defoliation timing (40 and 80 DAE). Neither defoliation level nor timing had an effect on peanut grade or maturity. Similarly, defoliation at 40 DAE did not affect pod yield but when damage occurred 80 DAE, pod yield was reduced 18.6 kg/ha for every 1% increase in defoliation. Considering average crop value and insect control costs, the economic injury for peanut defoliation at 80 DAE is 5% defoliation. These data indicate that control of canopy-feeding insects is only economically viable when defoliation exceeds 5% defoliation at 80 DAE.

scholarly journals Economic injury level for the flower thrips Frankliniella cf. gardeniae Moulton (Thysanoptera: Thripidae) in mango

2020 ◽  
Vol 73 (2) ◽  
pp. 9213-9220
Author(s):  
Paola Vanessa Sierra-Baquero ◽  
Edgar Herney Varón-Devia ◽  
Lucimar Gomes-Dias ◽  
Buenaventura Monje-Andrade
Keyword(s):  
Mangifera Indica ◽  
Economic Injury Level ◽  
Tropical Fruit ◽  
Flower Thrips ◽  
San Luis ◽  
Important Crop ◽  
Action Threshold ◽  
Economic Injury ◽  
Great Production ◽  
Linear Regressions

Mango is a tropical fruit with great production and market worldwide. In Colombia, it is an important crop with high export potential. There are many arthropods affecting mango production, such as thrips that feed on leaves, flowers, and small fruits, causing damage such as deformations, scars, and premature fall of fruits. This study aimed to establish the economic injury level (EIL) of Frankliniella cf. gardenia Moulton in mango (Mangifera indica L. var. yulima and var. tommy) in Guamo and San Luis (Tolima, Colombia). The methods employed included a weekly sampling of thrips in mango inflorescences during two productive periods (B-2015 and B-2016) using the structure tapping technique in a deep tray with mesh. Three preliminary thresholds per productive period were established: [B-2015: ≥10 thrips per inflorescence (TpI), ≥30 TpI, and ≥60 TpI. B-2016: ≥5 TpI, ≥10 TpI, and ≥15 TpI]. The variables density, costs, and yield were recorded. The EIL was calculated statistically using linear regressions and the final action threshold was estimated. An EIL of 11 TpI and an action threshold of 7 TpI were estimated for var. tommy in Guamo in the second semester of 2016. There was a risk of losing 220 kg ha-1 for each increase in insect unit in var. tommy. Therefore, thrips in mango behaved as an occasional pest, requiring control in var. tommy in Guamo, when the crop is flowering, and the population exceeds the action threshold of 7 TpI.

scholarly journals Economic Injury Level for Bermudagrass Stem Maggot (Diptera: Muscidae) in Bermudagrass Forage Production in Texas

2019 ◽  
Vol 112 (5) ◽  
pp. 2215-2221
Author(s):  
Allen E Knutson ◽  
Forrest Mitchell
Keyword(s):  
Vascular Tissue ◽  
Cynodon Dactylon ◽  
Forage Yield ◽  
Economic Injury Level ◽  
Forage Production ◽  
Market Values ◽  
Economic Injury ◽  
Stem Damage ◽  
And Control ◽  
The Impact

Abstract The bermudagrass stem maggot, Atherigona reversura Villeneuve (Diptera: Muscidae), was first reported damaging bermudagrass Cynodon dactylon (L.) Pers grown for forage in 2010 in the southeastern United States. Injury results from individual larvae feeding internally on the vascular tissue just above the terminal node of the grass stem. Injury slows plant growth and reduces forage accumulation. To address the need for economic guidelines to manage this new pest, the relationship between the percent of stems damaged by bermudagrass stem maggot and forage yield was measured in commercial bermudagrass hay fields in northcentral Texas. Yield loss was estimated to be 9.97 kg/ha (8.90 lbs /acre) for each percentage of stems with bermudagrass stem maggot damage. This relationship was used to calculate economic injury levels for a range of hay market values and control costs. The impact of stem damage on protein content, energy, and digestibility of bermudagrass hay was also investigated. Although there was a significant trend for declining forage quality with increasing stem damage, stem damage explained very little of the model’s variability.

scholarly journals Economic injury level and action thresholds for Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in maize crops

2020 ◽  
Vol 73 (1) ◽  
pp. 9065-9076 ◽  
Author(s):  
Camilo Ignacio Jaramillo-Barrios ◽  
Edgar Herney Varón-Devia ◽  
Buenaventura Monje-Andrade
Keyword(s):  
Spodoptera Frugiperda ◽  
Control Strategies ◽  
Insect Pest ◽  
Cultural Control ◽  
Production Costs ◽  
Yield Response ◽  
Total Production ◽  
Economic Injury Level ◽  
Economic Injury ◽  
Action Thresholds

Spodoptera frugiperda (J.E. Smith) is the pest insect that produces the highest losses in maize production in the tropics and neotropics. Its control in Colombia comprises about 10% of the total production costs. The aim of this study was to determine the economic injury level (EIL) and define action thresholds (ATs) for this insect pest in the maize hybrids 30F35R and 30F35HR (with Cry1F protein) in Espinal, Colombia. In two sowing cycles, a completely randomized design was established for each maize hybrid to measure their yield response at four insect population levels (a control without any applications of insecticides and applications at 2, 5, and 10 larvae per 10 plants). For 30F35R, an inverse relationship was found between levels of infestation and yields; meanwhile, for 30F35HR, only during the first cycle this relationship was found. The EIL calculated for 30F35R showed an average of 2.6 and 1.9 larvae per 10 plants in the first and second cycles, respectively, and 2.8 for 30F35HR in the first cycle. Two ATs were established, one in the period from 0 to 20 days after emergence (DAE) and another from 20 to 40 DAE. The threshold for 30F35R from 0 to 20 DAE showed an average of 1.8 larvae per 10 plants in both cycles, while, from 20 to 40 DAE, it was 2.0 and 1.7 in the first and second cycles, respectively. In 30F35HR, the thresholds were 2.1 and 2.5 larvae per 10 plants on average for both periods of the first cycle, respectively. These results can be considered as a tool within integrated pest management that also includes biological and cultural control strategies.

scholarly journals Perception and Use of Economic Thresholds Among Farmers and Agricultural Professionals: A Case Study on Soybean Aphid in Minnesota

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Natalie Hoidal ◽  
Robert L Koch
Keyword(s):  
Soybean Aphid ◽  
Educational Outreach ◽  
Economic Injury Level ◽  
Economic Thresholds ◽  
Foundational Principle ◽  
Economic Injury ◽  
Fundamental Misunderstanding ◽  
The Difference ◽  
Commercial Pesticide ◽  
Agricultural Professionals

Abstract Economic thresholds (ETs) are a foundational principle of integrated pest management but are not always widely accepted by farmers and agricultural professionals. This article reports on a survey of Minnesota farmer and agricultural professional perceptions of the ET for soybean aphid, Aphis glycines Matsumura (Hempitera: Aphididae). We discuss insights for Extension programs on how to frame the importance of thresholds and teach stakeholders to use them effectively. Key takeaways include farmers and agricultural professionals often worry about combined effects of insect, disease, and physiological pressures, whereas effects of interactions with these other stressors are seldom discussed in educational outreach. Across groups, there is a fundamental misunderstanding about the difference between ETs and economic injury level. Many survey participants reported believing in the ET but lacked the time and capacity to fully implement it. Sales agronomists and farmers were the least likely groups to trust the university-determined soybean aphid ET, whereas commercial pesticide applicators and independent consultants were the most likely groups to trust it. Based on these results, we recommend adapting communication about ETs based on the target audience to address common misconceptions and barriers to ET use that are unique to each group.

scholarly journals Mild Abiotic Stress Affects Development and Stimulates Hormesis of Hemp Aphid Phorodon cannabis

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 420
Author(s):  
Roma Durak ◽  
Malgorzata Jedryczka ◽  
Beata Czajka ◽  
Jan Dampc ◽  
Katarzyna Wielgusz ◽  
...  
Keyword(s):  
Glutathione Transferase ◽  
Insect Pest ◽  
Mild Stress ◽  
Population Parameters ◽  
Live Feed ◽  
Average Fecundity ◽  
The Impact ◽  
Considerable Damage ◽  
Group 1 ◽  
Future Management

The hemp aphid Phorodon cannabis Passerini is a well- known (Asia, Europe) or newly emerging (North America) insect. It is a monophagous insect pest causing considerable damage in field and glasshouse cultivations. The aim of this work was to study the effects of meteorological (temperature) and agronomical (herbicide) factors on the biology of the hemp aphid. In one experiment, hemp plants were kept at constant temperatures ranging from 20 to 30 °C, and aphid survival and fecundity were measured. In a related experiment conducted at 20 °C, plants were treated with field-appropriate rates of a selective graminicide containing quizalofop-P-tefuryl (40 gL−1, 4.38%, HRAC group 1), commonly used to control weeds in hemp, and aphid enzyme activity was measured in addition to population parameters. We found that hemp aphids could live, feed and reproduce within the whole studied range of temperatures, demonstrating its great evolutionary plasticity. However, the optimal temperature for development was 25 °C, at which the insect lived and reproduced for 25 and 15 days, respectively, with an average fecundity of 7.5 nymphs per reproduction day. The herbicide treatment increased the activity of superoxide dismutase (SOD), catalase (CAT), β-glucosidase, S-glutathione transferase (GST), oxidoreductive peroxidase (POD), and polyphenol oxidase (PPO) in the aphids, but only on certain days after treatment, which indicates a mild stress in aphid tissues, related to a higher reproduction and changed feeding behavior; aphids moved from the actively growing tips compared to untreated plants. The results of these experiments are discussed in terms of the impact on the future management of this pest.

CONTROLLING SUFETULA SPP.: A COCONUT INSECT PEST ON PEAT SOILS

2007 ◽  
Vol 43 (3) ◽  
pp. 289-299 ◽  
Author(s):  
X. BONNEAU ◽  
M. HUSNI ◽  
L. BEAUDOIN-OLLIVIER ◽  
JOKO SUSILO
Keyword(s):  
Insect Pest ◽  
Bare Soil ◽  
Cultural Control ◽  
Control Measures ◽  
Control Methods ◽  
Peat Soils ◽  
Depressive Effect ◽  
Moss Cover ◽  
Adult Insect ◽  
The Impact

We demonstrated experimentally that Sufetula, a root-mining insect, has a depressive effect on coconut yields on peat soils. The impact of the pest resulted in a shortfall in earnings that warranted taking control measures. We considered control methods suitable for rehabilitating infested mature coconut plantings and for preserving young coconut plantings. Currently, cultural control is the only effective method. It involves eliminating all identified shelters for the adult insect, i.e. fern cover and heaps of coconut waste (dry fronds and husks). The aim is to achieve totally bare soil, with moss cover that does not attract the pest, or planted with an unattractive intercrop such as pineapple.

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