scholarly journals Economic injury levels and economic thresholds for Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae) infesting seed maize

2017 ◽  
Vol 74 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Josemar Foresti ◽  
Cristina S Bastos ◽  
Flávio L Fernandes ◽  
Paulo R da Silva
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.


2013 ◽  
Vol 106 (3) ◽  
pp. 1274-1285 ◽  
Author(s):  
S. Paula-Moraes ◽  
T. E. Hunt ◽  
R. J. Wright ◽  
G. L. Hein ◽  
E. E. Blankenship

Author(s):  
Patricia J. Vittum

This chapter examines the principles of integrated pest management (IPM). IPM often is defined as a program that, in the context of the environment and the population dynamics of pests, uses many different techniques and strategies in as compatible a manner as possible to maintain pest population levels below those causing economic injury. The concept of IPM was initially developed in traditional agriculture, where the success of a crop was measured in economic yield (quantity and quality of produce). The key to such agricultural IPM programs has always been establishing consistent and reliable “economic thresholds” — pest populations at which the cost of expected crop damage exceeds the cost of implementing control. In turf, the expected economic benefit from reducing a pest population usually is much more difficult to measure than in agriculture. It is difficult, if not impossible, to determine the economic value of suppressing pest insects. As a result, “economic thresholds” in turf IPM usually are more accurately described as “tolerance levels,” or “action thresholds.” In a turf IPM program, the turf manager must determine what pest populations can be tolerated without incurring unacceptable damage. The basic components of an IPM approach include assessing a site, monitoring and predicting pest activity, setting thresholds, managing turf stress, identifying and optimizing management options, and evaluating the results.


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.


2018 ◽  
Vol 111 (5) ◽  
pp. 2242-2249 ◽  
Author(s):  
Marcus Vinícius Santana ◽  
Renan da S Macedo ◽  
Tássia Tuane M dos Santos ◽  
José A F Barrigossi

1980 ◽  
Vol 112 (8) ◽  
pp. 759-764 ◽  
Author(s):  
S. A. Ba-Angood ◽  
R. K. Stewart

AbstractArtificial infestations of cereal aphids in caged plants were made at different growth stages of barley in the field in 1978 and 1979. Forty, 80, 160, and 200 aphids/tiller reduced grain yield significantly (P < 0.01) when introduced into caged plants at flowering and milky stages for 2 weeks. Only the 150 and 200 aphids/tiller-treatments gave significant reductions in yield when introduction was at the mealy ripe stage. Twenty aphids/tiller gave a significant reduction in yield only when they were introduced at the beginning of ear emergence and flowering, but not at the milky ripe stage. Significant reduction in percentage protein was obtained only when 160 and 200 aphids/tiller were introduced at flowering and milky ripe stages. The economic injury and threshold levels were calculated as 10–18 and 8–16 aphids/tiller, respectively, depending on rate of increase of aphids, costs of chemical control, and the value of the crop in 1978 and 1979.


1989 ◽  
Vol 121 (9) ◽  
pp. 803-808
Author(s):  
O. Michaud ◽  
R.K. Stewart ◽  
Guy Boivin

AbstractEconomic injury levels and economic thresholds for nymphs of Lygocoris communis (Knight) were defined in apple orchards, using the beating technique. These were determined with 1987 apple market value and chemical control costs. Economic thresholds were established, assuming a 24-h period required for control implementation. Highly significant relationships were found between the damage at harvest and the captures of young nymphs of L. communis. The economic injury levels ranged from 0.4 to 5.8 young nymphs per sample unit depending on the sample unit and insecticide used.


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.


Author(s):  
Alejandro I Del Pozo-Valdivia ◽  
Dominic D Reisig ◽  
Lewis Braswell ◽  
Jeremy K Greene ◽  
Phillip Roberts ◽  
...  

Abstract Thresholds for Helicoverpa zea (Boddie) in cotton Gossypium hirsutum L. have been understudied since the widespread adoption of Bt cotton in the United States. Our study was possible due to the widespread presence of H. zea populations with Cry-toxin resistance. We initiated progressive spray timing experiments using three Bt cotton brands (Deltapine, Stoneville, and Phytogen) widely planted across the U.S. Cotton Belt expressing pyramided toxins in the Cry1A, Cry2, and Vip3Aa19 families. We timed foliar insecticide treatments based on week of bloom to manipulate H. zea populations in tandem with crop development during 2017 and 2018. We hypothesized that non-Bt cotton, cotton expressing Cry toxins alone, and cotton expressing Cry and Vip3Aa19 toxins would respond differently to H. zea feeding. We calculated economic injury levels to support the development of economic thresholds from significant responses. Pressure from H. zea was high during both years. Squares and bolls damaged by H. zea had the strongest negative yield associations, followed by larval number on squares. There were fewer yield associations with larval number on bolls and with number of H. zea eggs on the plant. Larval population levels were very low on varieties expressing Vip3Aa19. Yield response varied across experiments and varieties, suggesting that it is difficult to pinpoint precise economic injury levels. Nonetheless, our results generally suggest that current economic thresholds for H. zea in cotton are too high. Economic injury levels from comparisons between non-Bt varieties and those expressing only Cry toxins could inform future thresholds once H. zea evolves resistance to Vip3Aa19.


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