Skip to main content

NC State Extension

Tobacco Insect Scouting Methods

en Español / em Português
Español

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.


Português

Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.

Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.


English

English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Collapse ▲

Why should you scout insects in tobacco?

It is necessary to know the density of insects and their damage (per plant or per acre) to determine if and when insecticide treatments are necessary. Insects should only be treated when their densities exceed recommended economic thresholds. This practice ultimately saves money, protects workers and the environment, and has the potential to reduce pesticide residues by avoiding unnecessary applications Treating only when insects reach thresholds is also a key component of integrated pest management (IPM) practices required as part of tobacco GAP programs.

What are economic thresholds?

The economic threshold is the point at which plants should be treated to avoid damage that will result in monetary loss. Economic thresholds are set below the economic injury level (EIL), which is the point at which the cost of management is less than the loss incurred due to insect damage. Therefore, economic thresholds are conservative in recommending action before economic loss has occurred. See Radcliffe’s IPM World Textbook for a detailed description of economic thresholds and economic injury levels.

How do you scout insects in tobacco?

Tobacco fields should be scouting weekly following transplant through harvest. Current tobacco scouting recommendations suggest using the following sampling scheme, based on field size:

  • Very small fields (1-3 acres): Make 8 stops, randomly distributed throughout the field. At each stop, observe 5 plants for a total of 40 plants across the field.
  • Small fields (4-8 acres): Make 10 stops, randomly distributed throughout the field. At each stop, observe 5 plants for a total of 50 plants across the field.
  • Large fields: For each 4 acres a field exceeds 8 acres, add 2 stops (observing 5 plants at each stop), up to 20 stops total. Fields 28 acres or larger should have up to 20 stops total.

The more stops you make, the more accurate your scouting data will be. Fields should be scouting as they will be managed. If you will treat a field as a single unit, scout the acreage of the entire field. If the field is bisected by natural barriers, such as waterways or woods, and it will be managed as separate units, scout each section separately. Scouting locations within a field should be selected randomly to avoid bias. You can use a random set generator to create a random number table, which you can use to guide the number of rows and plants you will move after each stop. When scouting key tobacco insect pests, know how to identify them, when they are likely be active during the growing season, what plant part they are likely to injure, and the appropriate economic thresholds.

Record the number of insects per plant or the percentage of infested plants for each field and keep these records. An example of the type of scouting record we keep is here (Generic Scouting Sheet), and the scouting records from the Tobacco GAP Manual are available under “Records” at their site. GAP inspectors may ask to view these records. Also record what, if any, action was taken against pests and the outcome of that action. This information will be useful when making future management decisions.

When to scout for key tobacco pests

Not all tobacco pests are active at all times, so scouting efforts can be optimized by only observing pests that are likely to be active during a given growth stage or time of year.

Tobacco insect pest activity in relation to crop stage. Image: Hannah Burrack.

The pest-specific scouting guidelines below include a section on when to scout for each key pest.

Scouting methods for key tobacco pests

Scouting for Cutworms

Scouting for Soil Insect Pests

Scouting for Tobacco Flea Beetles

Scouting for Tobacco Budworms

Scouting for Green Peach Aphid 

Scouting for Hornworms

Scouting for Tobacco Splitworm

Scouting for Minor Foliar Pests 

Scouting for Thrips and TSWV

More information

Economic Thresholds and Economic Injury LevelsRadcliffe’s IPM World Textbook

Random set generator – Random.org

Written By

Hannah Burrack, N.C. Cooperative ExtensionDr. Hannah BurrackProfessor & Extension Specialist and Director of Education & Outreach, NC PSI Call Dr. Hannah Email Dr. Hannah Entomology & Plant Pathology
NC State Extension, NC State University
Page Last Updated: 6 months ago
Was the information on this page helpful? Yes check No close