Sampling Techniques and Setting Thresholds

2020 ◽  
pp. 381-398
Author(s):  
Patricia J. Vittum
Keyword(s):  
Sampling Techniques ◽  
Insect Management ◽  
Site Specific ◽  
Tolerance Level ◽  
Management Regime ◽  
Action Threshold ◽  
Insect Populations ◽  
Action Thresholds ◽  
Inspection Techniques ◽  
Standard Techniques

This chapter looks at sampling techniques and setting thresholds. The cornerstone of any integrated insect management regime is accurately identifying pest insects (including assessing population density) and developing appropriate action thresholds. Various methods have evolved by which the populations of insects present in the turf environment may be determined relatively rapidly and efficiently. These methods have become standard techniques for reporting insect densities. The chapter differentiates between passive sampling techniques (use of traps) and active visual inspection techniques (actual quantification of insect populations). Thresholds in turf integrated pest management usually are more accurately considered tolerance levels, or action thresholds. The tolerance level, or action threshold, for turfgrass insects is site-specific and depends on many factors.

scholarly journals Evaluation of Current Tarnished Plant Bug (Hemiptera: Miridae) Thresholds in Transgenic MON 88702 Cotton Expressing the Bt Cry51Aa2.834_16 Trait

2020 ◽  
Vol 113 (4) ◽  
pp. 1816-1822
Author(s):  
J C Corbin ◽  
T B Towles ◽  
W D Crow ◽  
A L Catchot ◽  
D R Cook ◽  
...  
Keyword(s):  
Southern United States ◽  
Lygus Lineolaris ◽  
Tarnished Plant Bug ◽  
Current Action ◽  
Action Threshold ◽  
Important Pest ◽  
Current Threshold ◽  
Action Thresholds ◽  
Insecticide Sprays ◽  
Recommended Action

Abstract The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important pest of cotton in many areas of the southern United States. An experiment was conducted at two locations in Mississippi during 2016 and 2017 to evaluate action thresholds for tarnished plant bug on a novel Bacillus thuringiensis cotton that expresses the Cry51Aa2.834_16 toxin. Treatments included the current action threshold, a 2× threshold, and treatments where insecticides were only applied during the early season (preflower) or only during late season (during flowering) based on the current action thresholds. These were compared to an untreated control and a weekly insecticide use regime that received weekly insecticide sprays. All treatments were imposed on both Bt Cry1Aa2.834_16 cotton and a nontraited cotton. The Bt Cry1Aa2.834_16 trait reduced the number of tarnished plant bugs and injury, and improved yields compared to nontraited cotton. For all spray treatments except the weekly insecticide use regime, yields were greater for the Bt Cry51Aa2.834_16 cotton than the nontraited cotton. In terms of thresholds, Bt Cry1Aa2.834_16 cotton sprayed based on current action thresholds resulted in similar yields to the weekly insecticide use regime of both cotton types. In contrast, the 2× threshold resulted in lower yields than the current threshold for both cotton types. Though thresholds intermediate to the currently recommended action threshold and the 2× threshold were not tested, these data suggest that currently recommended action thresholds appear appropriate for Bt Cry51Aa2.834_16 cotton. These results suggest that this trait will be an important component of current IPM programs in cotton where tarnished plant bug is an important pest.

AN ACTION THRESHOLD FOR CONTROL OF LEPIDOPTEROUS PESTS OF CABBAGE IN PRINCE EDWARD ISLAND

1994 ◽  
Vol 126 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Andrew P. Dornan ◽  
Jeff G. Stewart ◽  
Mark K. Sears
Keyword(s):  
Plutella Xylostella ◽  
Trichoplusia Ni ◽  
Prince Edward Island ◽  
Growth Stage ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Cabbage Looper ◽  
Fresh Market ◽  
Action Threshold ◽  
Insect Populations

AbstractAction thresholds for imported cabbageworm, Pieris rapae (L.), diamondback moth, Plutella xylostella (L.), and cabbage looper, Trichoplusia ni (Hübner), were evaluated on two cultivars of cabbage, Brassica oleracea var. capitata (L.), in Prince Edward Island. Thresholds were tested on plots of mid-season cabbage, cv. Minicole, and late-season cabbage, cv. Lennox, both grown for fresh market in 1991 and 1992. Management of larval populations at a threshold of 0.25 Cabbage Looper Equivalents (CLE) per plant resulted in yields equal to those obtained with bi-weekly applications or grower treatments. Higher thresholds of 0.50 and 1.0 CLE per plant were not as useful and did’ not consistently result in yields greater than untreated plots. Use of the threshold of 0.25 CLE per plant reduced the number of applications of insecticides by 30% compared with spraying insecticide at bi-weekly intervals from heading to harvest, and 43% compared with management by the grower without regard to insect populations or growth stage of the crop.

scholarly journals Population Dynamics of Spotted Wing Drosophila (Drosophila suzukii Matsumara) in Maine Wild Blueberry (Vaccinium angustifolium Aiton)

2019 ◽  
Author(s):  
Francis Drummond ◽  
Elissa Ballamn ◽  
Judith Collins
Keyword(s):  
Relative Abundance ◽  
Predation Rate ◽  
Drosophila Suzukii ◽  
Insecticide Application ◽  
Wild Fruit ◽  
Air Temperatures ◽  
Action Threshold ◽  
Gamma Density ◽  
Action Thresholds ◽  
Wild Blueberry

A long-term investigation of D. suzukii dynamics in wild blueberry fields from 2012 - 2018 demonstrates relative abundance is still increasing seven years after initial invasion. Relative abundance is determined by physiological date of first detection and air temperatures the previous winter. Date of first detection of flies does not determine date of fruit infestation. The level of fruit infestation is determined by year, fly pressure, and insecticide application frequency. Frequency of insecticide application is determined by production system. Non-crop wild fruit and predation influences fly pressure; increased wild fruit abundance results in increased fly pressure. Increased predation rate reduces fly pressure, but only at high abundance of flies, or when high levels of wild fruit are present along field edges. Male sex ratio might be declining over the seven years. Action thresholds were developed from samples of 92 fields from 2012 - 2017 that related cumulative adult male trap capture to the following week likelihood of fruit infestation. A two-parameter gamma density function describing this probability was used to develop a risk-based gradient action threshold system. The action thresholds were validated from 2016-2018 in 35 fields and were shown to work well in two of three years (2016 and 2017).

Developing action thresholds for codling moth (Lepidoptera: Tortricidae) with pear ester- and codlemone-baited traps in apple orchards treated with sex pheromone mating disruption

2005 ◽  
Vol 137 (6) ◽  
pp. 739-747 ◽  
Author(s):  
A. L. Knight ◽  
D.M. Light
Keyword(s):  
Cydia Pomonella ◽  
Codling Moth ◽  
Cumulative Number ◽  
Egg Hatch ◽  
Baited Traps ◽  
Action Threshold ◽  
Pear Ester ◽  
Low Levels ◽  
Action Thresholds ◽  
Insecticide Spray

AbstractTraps baited with either ethyl (E,Z)-2,4-decadienoate (pear ester) or (E,E)- 8,10- dodecadien-1-ol (codlemone) (Pherocon® CM-DA™ and Megalure CM™ lures, respectively) were used to develop action thresholds for codling moth (Cydia pomonella (L.)) in apple (Malus domestica Borkh.; Rosaceae) orchards treated with sex pheromones for control of this pest. Studies were conducted in 102 orchards treated with 500–1000 ISOMATE®-C PLUS dispensers per hectare during 2000–2002. Pairs of traps were placed within two 1.0-ha plots within each orchard. Fruit injury was assessed at mid-season and prior to harvest in each plot. The numbers of female and total moths caught in pear ester-baited traps and male moths caught in codlemone-baited traps were used to develop action thresholds. Thresholds were based on the minimum cumulative number of moths per trap in ≥95% of traps in unsprayed plots with no fruit injury. Specific thresholds were established for the first insecticide spray targeting the start of egg hatch and for the first and second moth flights. The proportion of plots with mid-season fruit injury that had cumulative moth catches below the action threshold at first spray and at second moth flight was determined using the established action threshold and thresholds reduced incrementally to ≥1 moth per trap. Moth catches below the threshold at first spray were less common in plots with high levels of fruit injury (>0.3%) than in plots with low levels of fruit injury and more common with codlemone-baited traps than with pear ester-baited traps. An action threshold of ≥1 moth in a pear ester-baited trap at first spray eliminated the error in predicting fruit injury in plots at mid-season. Conversely, a high proportion of traps baited with either lure failed to predict low levels of fruit injury at harvest in unsprayed plots regardless of the cumulative moth threshold used during the second moth flight.

Silica Nanoparticles for Insect Pest Control

2019 ◽  
Vol 25 (37) ◽  
pp. 4030-4038 ◽  
Author(s):  
Mariano Cáceres ◽  
Claudia V. Vassena ◽  
M. Dolores Garcerá ◽  
Pablo L. Santo-Orihuela
Keyword(s):  
Silica Nanoparticles ◽  
Control Strategies ◽  
Insect Pest ◽  
Pest Species ◽  
Negative Consequences ◽  
Promising Alternative ◽  
Insect Management ◽  
Pest Insect ◽  
Insect Pest Control ◽  
Insect Populations

To date, control strategies used against insect pest species are based on synthetic insecticide applications. In addition, the efficacy of these treatments could be decreased due to insecticide resistance in insect populations. Also, the irrational use of chemical control strategies has negative consequences of non-target organisms and threatening human health. Designing nanomaterial for pest insect control is a promising alternative to traditional insecticide formulations. In particular, it has been proven that silica nanoparticles have the potential for molecules delivery, release control improvement and also their toxicity as insecticide alone. In this work, we summarized the state of knowledge on silica nanoparticles (SiNPs) used in pest insect management. Besides, aspects of their synthesis, mode of action, and toxic effects on non-target organisms and environment are reviewed.

THE MICROBIOLOGICAL CONDITION OF WOOD OF LIVING BALSAM FIR AND BLACK SPRUCE IN QUEBEC

1967 ◽  
Vol 45 (7) ◽  
pp. 1003-1010 ◽  
Author(s):  
D. E. Etheridge ◽  
L. A. Morin
Keyword(s):  
Standard Method ◽  
Black Spruce ◽  
Balsam Fir ◽  
Sampling Techniques ◽  
Ecological Studies ◽  
Decay Fungi ◽  
The Past ◽  
Negative Results ◽  
Low Activity ◽  
Standard Techniques

Determinations of bacterial and fungal microfloras were made on 2% malt agar slants from wood samples of a living balsam fir, by following standard techniques for the isolation of decay fungi. Comparative studies with other microbiological sampling techniques and with different media have demonstrated (i) the general suitability of the standard method for ecological studies of wood-inhabiting microorganisms, and (ii) the validity of negative results obtained in previous isolation studies with the standard method. These findings reveal the pith column as a major center of bacterial activity in balsam fir, with relatively low activity recorded for the heartwood, and none at all in the sapwood. There is evidence that a similar situation exists in living black spruce, although the level of microbiological activity was much lower in the heartwood of this species, and bacteria almost nonexistent. Isolation studies conducted over the past 3 years in Quebec revealed that 40% of 132 living balsam fir trees and over 90% of 42 living black spruce trees sampled had sterile heartwood and sapwood. Retinocyclus abietis (Crouan) Groves and Wells was the only fungus isolated from both heart-wood and sapwood of the two species.

scholarly journals Population Dynamics of Spotted Wing Drosophila (Drosophila suzukii (Matsumura)) in Maine Wild Blueberry (Vaccinium angustifolium Aiton)

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 205 ◽  
Author(s):  
Francis Drummond ◽  
Elissa Ballman ◽  
Judith Collins
Keyword(s):  
Relative Abundance ◽  
Predation Rate ◽  
Drosophila Suzukii ◽  
Insecticide Application ◽  
Wild Fruit ◽  
Air Temperatures ◽  
Action Threshold ◽  
Gamma Density ◽  
Action Thresholds ◽  
Wild Blueberry

A long-term investigation of D. suzukii dynamics in wild blueberry fields from 2012–2018 demonstrates relative abundance is either still increasing or exhibiting periodicity seven years after the initial invasion. Relative abundance is determined by physiological date of first detection and air temperatures the previous winter. Date of first detection of flies does not determine date of fruit infestation. The level of fruit infestation is determined by year, fly pressure, and insecticide application frequency. Frequency of insecticide application is determined by production system. Non-crop wild fruit and predation influences fly pressure; increased wild fruit abundance results in increased fly pressure. Increased predation rate reduces fly pressure, but only at high abundance of flies, or when high levels of wild fruit are present along field edges. Male sex ratio might be declining over the seven years. Action thresholds were developed from samples of 92 fields from 2012–2017 that related cumulative adult male trap capture to the following week likelihood of fruit infestation. A two-parameter gamma density function describing this probability was used to develop a risk-based gradient action threshold system. The action thresholds were validated from 2016–2018 in 35 fields and were shown to work well in two of three years (2016 and 2017).

Dispersal From Overwintering Sites, Action Thresholds for Blueberry Maggot Fly (Diptera: Tephritidae), and Factors That Can Influence Variation in Predicted Fruit Infestation Levels in Maine Wild Blueberry: Part I

2019 ◽  
Vol 113 (2) ◽  
pp. 851-859 ◽  
Author(s):  
Francis A Drummond ◽  
Judith A Collins
Keyword(s):  
Field Studies ◽  
Site Quality ◽  
Physiological Status ◽  
Rhagoletis Mendax ◽  
Action Threshold ◽  
Action Thresholds ◽  
The University ◽  
Blueberry Maggot Fly ◽  
Wild Blueberry ◽  
Overwintering Site

Abstract Between 1996 and 2003 field studies were conducted in wild blueberry, Vaccinium angustifolium Aiton (Ericales: Ericaceae) to determine action thresholds for the blueberry maggot fly, Rhagoletis mendax Curran (Diptera: Tephritidae). Thresholds were based upon cumulative fly trap captures on baited Pherocon AM traps. The cumulative numbers of R. mendax flies captured over time was a significant predictor of infested fruit levels (maggots/liter blueberries). Fifty percent of the variance in fruit infestation is explained by fly captures. Based upon this relationship, the University of Maine Cooperative Extension has recommended action threshold of 10 cumulative fly captures/trap. However, this threshold is liberal in terms of risk as only 50% of the variance in fruit infestation is explained by fly captures. The dynamics of colonization rate and fly physiological status entering fruit-bearing fields might partially explain the variance in the action threshold. The majority of flies emerge from pruned fields or along forest scrub/shrub field edges, and it takes between 1 and 10 d (mean = 4.1 ± 0.9 d) for the populations to enter adjacent fruit-bearing fields. Flies dispersed from pruned fields at a decreasing rate the farther they dispersed. The rate of dispersal into fruit-bearing wild blueberry fields also depends upon the overwintering site quality. Sites with fruit exhibited both delayed colonization and lower colonization rates into fruit-bearing fields than adjacent pruned fields with no fruit. We also found that as the season progressed the proportion of flies capable of laying eggs varied greatly by location and year.

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