As most growers know, agricultural pests are a common, yet unfortunate, nuisance. Insect pests cause damage to crops and to your profits.
There are two kinds of crop damage caused by insect pests, according to Agrivi:
- Direct injury to the crop, which is caused by insect feeding.
- Indirect damage to the crop in which insects transmit diseases. These types of insect pests are called vectors.
Direct injury is the most common type of crop damage, however, insects can still cause serious damage by transmitting diseases as well. The most common diseases transmitted are viral, bacterial, or fungal diseases.
Agrivi also notes that Insects can transmit disease in three different ways:
- Accidental or incidental transmission. This is where the disease occurs during insect feeding or oviposition, where eggs are deposited.
- Passive transmission. This is where the insect transmits the disease from one plant to another, without actually feeding on the plant.
- Active transmission. This is where the disease occurs when the insect that carries the pathogen feeds on a plant, and then moves on to a healthy plant and transmits the pathogen.
Insects have the potential to severely harm crop production, and cause significant losses for growers. That economic loss is not only measured by estimating impacts on yield. The cost of insect control must be equal to, or less than, the loss in profit that would result from uncontrolled insect populations.
Managing Agricultural Pests
There are currently a wide array of pest control tools available to growers. These tools include both preventative and defensive measures.
Preventative measures include planting resistant non-host varieties, adaptation of planting and harvest timing, selecting non-host crop types in crop rotation, varietal blending, and thoroughly cleaning seed.
Defensive measures are broken down into four main categories:
- Biological. This includes the use of natural enemies (using various beneficial viruses, fungi, bacteria, and insects as predators).
- Cultural. This includes weather tracking and the monitoring of fields and crops.
- Physical. This includes disinfection of the soil, seed, and seedlings.
- Chemical. This includes the use of insecticides.
Applying insecticides is the most common protection method used by conventional growers. Unfortunately, resistance to insecticides in agricultural pests is an urgent problem that affects growers worldwide. Also, environmental regulations are increasingly limiting the use of chemical insecticide in efforts to increase sustainability, ensure safety of consumption, and protect other susceptible neutral or beneficial insect populations. Because of this, it’s best for growers to take an integrated approach when it comes to managing agricultural pests. This means combining insecticide use with the use of various biological, cultural, and physical measures as well.
Integrated Pest Management
According to Science Direct, integrated pest management is a sustainable approach to managing pests by combining different tools and strategies including insecticides, natural predators, cultural practices, and host–plant resistance in a way that minimizes both economic and environmental risks. The purpose of IPM is to balance the need for pest control with the desire to avoid, or at least reduce, the negative impacts of heavy pesticide use.
- Inspection. The IPM process starts with inspection and identification of the pest. During this stage you’ll want to identify beneficial, neutral, and harmful insects.
- Monitoring. After inspection, monitoring begins immediately, including tracking pest populations, life cycle and stages, as well as factors that influence the degree of crop feeding and damage.
- Set thresholds. Set limits for tolerable pest damage. Determine insect populations required to negatively impact yield to the point where the cost of control methods maintain profit.
- Plan. Establish an effective plan of control before pests cause concern.
- Action. Take prompt, effective action when economically significant populations are realized.
Many experts see IPM being employed as part of a redesign of the crop management system aimed at lowering pest pressure, while also reducing pesticide use. The development of IPM can be more time-consuming than simply using pesticides to control the problem. However, the use of several tactics working together is a growers best choice to combat stubborn pests and diseases, while avoiding chemical overuse and resistance. This will ultimately provide economic savings for the grower, while protecting both the environment and human health.