Trap-Based Economic Injury Levels and Thresholds for Euschistus servus (Hemiptera: Pentatomidae) in Florida Peach Orchards

2020 ◽  
Vol 113 (3) ◽  
pp. 1347-1355 ◽  
Author(s):  
Cory Penca ◽  
Amanda C Hodges ◽  
Norman C Leppla ◽  
Ted E Cottrell

Abstract Populations of the brown stink bug, Euschistus servus (Say), in Florida peach orchards were monitored during the 2017 and 2018 growing seasons using yellow pheromone-baited pyramid traps. Peaches were evaluated at harvest for the presence of stink bug injury. A relationship between E. servus trap capture and fruit injury was used to estimate the economic injury level (EIL) for varying scenarios of crop price, per-hectare yield, and control costs. Economic thresholds were then set based on observed E. servus population trends and expected rates of increase. Thresholds were lowest in the period immediately following shuck split due to the rapid increase in E. servus populations during this period. Euschistus servus trap capture trended downward at the time of harvest. Therefore, increased E. servus management early in the Florida peach season provides the greatest overall benefit, whereas late season populations decline independent of management actions. The proposed EIL for Florida peaches determined by this study is 5.53 E. servus per trap over a 14-d trapping period, which was surpassed in only 16 of the 60 recorded trapping periods. This suggests that the current recommended spray frequency may not be economically justified.

2020 ◽  
Vol 113 (5) ◽  
pp. 2250-2258
Author(s):  
Tim B Bryant ◽  
Seth J Dorman ◽  
Dominic D Reisig ◽  
DeShae Dillard ◽  
Roger Schürch ◽  
...  

Abstract Economic yield loss and reduction in grain quality from brown stink bug, Euschistus servus (Say), feeding injury in early and late stages of maize, Zea mays (Poales: Poaceae, Linnaeus), development was assessed in Virginia and North Carolina in 2018 and 2019. Varying levels of stink bug infestations were introduced to seedling maize (V2—early stage), and a range of late-stages of maize, including 1) the last stage of vegetative development (V12/V14), 2) prior to tasseling, 3) at tasseling (VT), and 4) across all tested late growth stages. Euschistus servus infestation levels included 33, 67, and 100% of maize seedlings, and 25, 50, 100, and 200% of plants during later stages. Infestations were maintained on seedling maize for 7 d, and 8 or 16 d in reproductive stages. Infestation level in seedling maize had an impact on grain yield. Infestation level and growth stage both had an impact on grain yield in reproductive maize. The percentage of discolored kernels was also affected by infestation level, but not growth stage. Regression analysis between grain yield and infestation level indicated that the average economic injury level is 7% in seedling maize (7 bugs/100 plants) and 12% (12 bugs/100 plants) from the last vegetative stages (V12/V14) through pollination (VT). The economic injury level in the late vegetative stages is only applicable when infestations are present for an extended period of time (16 d), emphasizing the need for continued scouting of maize throughout the season to make informed management decisions.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Natalie Hoidal ◽  
Robert L Koch

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.


2010 ◽  
Vol 41 (No. 4) ◽  
pp. 158-164 ◽  
Author(s):  
E.A. Egwurube ◽  
O. Ogunlana M ◽  
C. Dike M ◽  
I. Onu

Population studies and tests on the relationship between density and damage were conducted in 1999 to 2001 to determine the pest status of <I>Empoasca dolichi</I> on groundnut (<I>Arachis hypogaea </I>L.) in the Zaria area of northern Nigeria. Analyses showed that <I>Empoasca</I> numbers varied significantly from one year to another, and within each year the numbers of leafhoppers observed at the different growth stages of the plant were significantly different (<I>P</I> = 0.01). There was an inverse and highly significant relationship between the mean kernel yield and the <I>Empoasca </I>damage at the different growth stages of the plant. When natural population densities were plotted against economic injury level (EIL), the densities did not reach the EIL throughout the groundnut growing seasons. The insect was thus not an economic pest on groundnut in Zaria during the period of the study.


1969 ◽  
Vol 72 (3) ◽  
pp. 375-385
Author(s):  
Alejandro E. Segarra-Carmona ◽  
Alberto Pantoja

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.


2016 ◽  
Vol 46 (3) ◽  
pp. 324-335 ◽  
Author(s):  
M F Soria ◽  
P E Degrande ◽  
A R Panizzi ◽  
M D Toews

2004 ◽  
Vol 61 (6) ◽  
pp. 584-592 ◽  
Author(s):  
André Luiz Lourenção ◽  
Nelson Raimundo Braga ◽  
Manoel Albino Coelho de Miranda ◽  
Paulo César Reco ◽  
Giuliana Etore do Valle ◽  
...  

The use of soybean cultivars resistant to insects and diseases reduces the application of pesticides, decreasing production costs and promoting a sustainable agriculture. The damage of stink bugs and defoliators and the severity of powdery mildew (Microsphaera diffusa) in soybean of three maturity groups were evaluated under field conditions, at Tarumã and Ribeirão Preto, State of São Paulo, Brazil. Three experiments, one for each group, were carried out in the 1999/2000 and 2000/2001 growing seasons. In 1999/2000, the disease occurred in Tarumã; in that year, infestation of chrysomelids (Cerotoma sp. and Colaspis sp.) was observed in Ribeirão Preto. Low infestations of stink bugs occurred in both years and locations, but in Tarumã, at the stage of plant maturation, the insect population exceeded the economic injury level. The severity of powdery mildew was evaluated using a scale varying from 1 (no symptom) to 5 (more than 50% of leaves with symptoms). Chrysomelid injuries were estimated by the percentage of leaf area removed, and stink bug damage was evaluated by the percentage of leaf retention (LRP) and yield. Within the early maturity group (110 days), IAC 94-2675 showed good yield levels, low LRP, and resistance to powdery mildew. In the genotypes of the 120-day maturity group, IAC 94-5, IAC 94-1172, IAC 94-1017, IAC 94-133, and IAC 94-745 presented good yield; the last two behaved as resistant to the disease. With regard to the genotypes of the 135-day maturity group, IAC 93-1564 and IAC 94-2939 showed good yield, low LRP, and resistance to powdery mildew.


1980 ◽  
Vol 112 (3) ◽  
pp. 301-305 ◽  
Author(s):  
R. K. Stewart ◽  
A. R. Khattat

AbstractAdult and nymphal populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), on “Contender” green beans, Phaseolus vulgaris L., were sampled during the summers of 1971–1972. Sweep net and D-Vac® suction apparatus samples were taken concurrently, and both estimates were compared by regression analysis.The tarnished plant bug reached levels above the economic injury levels for both early and late crops in 1971–1972. The economic threshold was determined as 0.5 insect/10 plants below the economic injury level.


2007 ◽  
Vol 15 (04) ◽  
pp. 539-550 ◽  
Author(s):  
WEIJIAN XU ◽  
SHIDONG CHEN ◽  
LANSUN CHEN

In most models of pest control, the time of prevention and control is always assumed to be unrestricted. In practice, however, it is usually required in agriculture and forestry that we control the pest density to be lower than the economic injury level in a given time. By constructing the dynamics of logistic differential equation with impulsive effect, this paper describes the process of pest control through impulsive spraying pesticide in a given time, and then the existence condition of the solution to the boundary value problem of the dynamics is obtained, with which we solve the problem of pest control on a finite period of time and discuss the governing strategies.


2019 ◽  
Vol 112 (5) ◽  
pp. 2215-2221
Author(s):  
Allen E Knutson ◽  
Forrest Mitchell

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.


2013 ◽  
Vol 50 (2) ◽  
pp. 107-116
Author(s):  
Satyabrata Pal ◽  
Arunava Ghosh ◽  
Tapamay Dhar

Summary Economic threshold level (ETL) is an important component in pest management and control. Usually, it is determined by the grower/technologist utilizing his experience on a crop; however, for cereals the values of these indices are available. Knowledge of ETL helps reduce crop loss (and ensure less pesticide application), and as a consequence, profit is increased. Also substantial knowledge is required on the dynamics of the pest population, in order to determine the density at which the economic injury level (EIL) may be prevented (Weersink et al. 1991). This paper is devoted to the development of an analytical method (probabilistic) for determination of ETL, which is defined as the density at which control measures should be determined to prevent an increasing pest population from reaching the economic injury level. A method to model the dynamics of the pest population is also proposed. The above method is demonstrated on a real life data set on pest (whitefly) incidence on betelvine, obtained from an experiment designed for that purpose.


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