Skip to main content

NC State Extension

Thresholds

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 ▲

Thresholds are a critical part of any integrated pest management (IPM) program. The thresholds presented here are economic thresholds (ET), in which the density of a pest has reached a point at which a management intervention (in this case a pesticide application) is economically justified. An economic threshold should not be confused with the economic injury level (EIL). An economic injury level is the lowest population density of a pest that will cause economic damage. Treatment when economic injury level is reached may result in the highest yields, but may not necessarily be the most cost-effective. Treatment at the economic threshold is the most cost-effective management approach, and may or may not result in the highest yields.

For specific information, please consult the individual pest pages for various management strategies, tactics and applicable threshold information. Below you will find information on corn earworm (soybean podworm) and stink bug thresholds in soybeans.

Applying thresholds: When scouting, some level of insects and their damage will always be observed. However, most situations will not result in yield loss since the insect numbers present are too low to produce injury beyond the plant’s compensation ability. Thresholds are levels of pest injury or insect numbers (that are assumed to cause injury) that will result in yield loss beyond the cost of a remedial action (usually spraying with an insecticide). Current thresholds for soybean insect pests in North Carolina are:

Defoliation threshold (any insect or group of insects) — 30% foliage loss up to two weeks prior to blooming or 15% foliage loss from two weeks prior to flowering and until pods have filled.

Corn earworm thresholds – Use the online corn earworm in soybean threshold calculator, and visit the corn earworm soybean pest page for updated information.

Stink bug thresholds- Use the online stink bug in soybean threshold table, and visit stink bug soybean pest page for updated information.

Kudzu bug thresholds: Our threshold for spraying is five bugs per plant until mid-July, when we switch to a sweep net-based threshold. Remember that when you spray colonizers during the early season (the adults) you may have to spray again and again. Our best kudzu bug insecticides have little to no residual to control the insect. Once the migration period is over, they can easily be managed with a single spray since they are not difficult to kill.

After mid-July, kudzu bug is more effectively sampled with a sweep net. Several randomly selected samples of 15 sweeps (defined, firm pendulum “swooshes” of the net) per sample should be taken from interior areas of the field. A preliminary threshold of one nymph-stage bug per sweep (i.e.,15 nymphs per 15-sweep sample) is recommended and may help reduce the need for multiple sprays.