Economic Injury Level for Second-Generation Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) in Two-Year-Old Populus

2002 ◽  
Vol 95 (2) ◽  
pp. 313-316 ◽  
Author(s):  
Ying Fang ◽  
Larry P. Pedigo ◽  
Joe P. Colletti ◽  
Elwood R. Hart
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.


1979 ◽  
Vol 111 (5) ◽  
pp. 551-556 ◽  
Author(s):  
T.R. Burkot ◽  
D.M. Benjamin

AbstractAdults and larvae of the cottonwood leaf beetle, Chrysomela scripta Fab., defoliated tissue cultured Aigeiros (Populus × euramericana (Dode) Guinier) subclones and destroyed apical tips. Fecundity was 510 ± 153 eggs . Four generations occurred between May and September in southern Wisconsin. Maximal insect numbers and damage occurred in the third generation. The minimal developmental threshold was 10.8 °C with a mean 257 ± 26 day-degree (°C) required per generation. Important biological control agents included Coleomegilla maculata, which consumed up to 25% of the eggs, and Shizonatus latus, a pteromalid parasite, which destroyed up to 26% of the pupae.


2019 ◽  
Vol 123 ◽  
pp. 30-35 ◽  
Author(s):  
Jhersyka da S. Paes ◽  
Tamíris A. de Araújo ◽  
Rodrigo S. Ramos ◽  
João Rafael S. Soares ◽  
Vitor C.R. de Araújo ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 291 ◽  
Author(s):  
Maja Meseldžija ◽  
Miloš Rajković ◽  
Milica Dudić ◽  
Milica Vranešević ◽  
Atila Bezdan ◽  
...  

The aim of this study was to investigate the efficacy and phytotoxicity of herbicides in combinations and to determine their economic feasibility in the soybean crop. The trials were placed at two locations, Pobeda and Budisava (Serbia), during 2016 and 2018, organized in a randomized block design with four replicates of all herbicide combinations (metribuzin + S-metolachlor; imazamox + oxasulfuron + typhenesulfuron-methyl; metribuzin + S-metolachlor + imazamox + oxasulfuron + typhenesulfuron-methyl; and bentazon + imazamox + typhenesulfuron-methyl). At the first location, 16 weed species were determined, while in the second location, 14 were determined. The highest reduction in the number of weeds was achieved at the first location, using a combination of herbicides metribuzin + S-metolachlor + imazamox + oxasulfuron + typhenesulfuron-methyl with a total efficacy that ranged from 96.98% to 97.40%. Only on the second location bentazone + imazamox + tifensulfuron-methyl showed passable phytotoxicity on soybean, during both years. Based on the established economic justification, in the combinations of metribuzin + S-metolachlor + imazamox + oxasulfuron + typhenesulfuron-methyl, yield was increased for 2350 kg/ha or 1.91 times more, according to the untreated variant at first location. The economic injury level at the most effective combination of herbicides was 52.70 weeds/m2.


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