90 DAT Hard Dough Stage| How to Control Brown Plant Hopper?

Yes, insecticides can be used to wipe out or control brown plant hopper (BPH) infestations in hybrid rice, but their effectiveness can be complicated by the development of insecticide resistance in BPH populations and the fact that the hoppers often feed at the base of the plant where it's hard to reach. To manage BPH effectively, it's best to use insecticides as part of an integrated pest management (IPM) strategy, focusing on targeted application and avoiding broad-spectrum chemicals to protect natural enemies and prevent the development of resistance. 

When and how to use insecticides:

Apply only when necessary:

Insecticides should be used only when pest populations exceed established economic thresholds, meaning there are more hoppers than natural enemies, and flooding the field is not an option. 

Target the application:

Direct sprays to the base of the plants, where nymphs are located, rather than broad foliar applications. 

Consider seed treatment:

Applying systemic insecticides to seeds in the nursery before transplanting can provide effective control, especially in areas with predictable population growth patterns. 

Use specific insecticides:

Choose growth regulators (like buprofezin) to target nymphs or specific systemic insecticides rather than broad-spectrum chemicals. 

Complications and why to be cautious:

Resistance:

Brown plant hoppers have developed resistance to several classes of insecticides, which can reduce their effectiveness. 

Insecticide-induced resurgence:

Repeated use of certain insecticides can stimulate the growth and reproduction of the pest population. 

Damage to natural enemies:

Broad-spectrum insecticides are highly toxic to bees, parasitoids, and predators of BPH, which can lead to outbreaks. 

Feeding habits:

BPH nymphs feed near the water level at the base of the plant, making them difficult to reach with foliar sprays. 

Integrated Pest Management (IPM) Approach:

Integrated approach:

Combine chemical control with other methods like using resistant hybrid rice varieties, draining fields, splitting nitrogen application, and maintaining synchronous planting to reduce BPH build-up. 

Monitor for natural enemies:

Always check the population of natural enemies before applying insecticides, as they are a key part of the IPM system. 

Rotate insecticides:

To delay the development of resistance, use insecticides with different modes of action.
Yes, it is generally true that avoiding insecticides during the early stages of rice growth (0–30/40 days after planting) helps protect beneficial insects and prevent pest outbreaks. Beneficial insect populations can naturally control pests during this period, but indiscriminate spraying can kill these natural enemies, leading to imbalances and larger pest infestations later in the season. Embracing Integrated Pest Management (IPM) principles, which emphasize non-chemical methods, is key to maintaining a healthy agroecosystem and sustainable rice production.
 

Why Avoid Early Insecticide Application?

Promotes Natural Enemies:

In the early stages, natural predators and parasites are crucial for controlling pest populations. Sprays kill these beneficial insects, removing natural biological control and leading to an imbalance. 

Prevents Secondary Pest Outbreaks:

By allowing natural enemies to thrive, you prevent the conditions that lead to outbreaks of secondary pests, such as brown plant hoppers. 

Plant Compensation:

Young rice plants can often compensate for minor damage from early pests, making insecticide intervention unnecessary. 

Ecological Balance:

Minimizing insecticide use preserves the overall health of the rice ecosystem, which is vital for sustainable agriculture. 

Integrated Pest Management (IPM)

Focus on Biological Control:

Utilize biological management strategies that focus on utilizing natural enemies like small wasps, big wasps, tachinid flies, and spiders to control pests. 

Agronomic Practices:

Healthy crops are less susceptible to pests. Practices like proper mulching, water management, and correct nutrient status for the plant contribute to pest resistance. 

Observation and Timing:

Monitor your fields for signs of pests and diseases. If spraying is absolutely necessary, timing is crucial to target pests when they are most vulnerable and to avoid impacting beneficial insects. 

Least Toxic Options:

When chemical control is unavoidable, choose the least toxic alternatives and consider applying them during cooler parts of the day to minimize harm to non-target organisms.