Model Answer
0 min readIntroduction
Sugarcane, a vital agricultural commodity, is susceptible to a wide array of pests that can significantly reduce yield and quality. Among these, the sugarcane borers are particularly destructive. The stalk borer, *Chilo infuscatellus Snell*, is a major pest in India and other Asian countries, causing substantial economic losses. Understanding its biology, damage potential, and effective control strategies is crucial for sustainable sugarcane production. This answer will detail the systemic position, life cycle, damage, and control measures related to *Chilo infuscatellus*.
Systematic Position of *Chilo infuscatellus*
The sugarcane stalk borer, *Chilo infuscatellus Snell*, belongs to the insect order Lepidoptera (moths and butterflies). Its taxonomic classification is as follows:
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Lepidoptera
- Family: Pyralidae
- Genus: *Chilo*
- Species: *infuscatellus*
Life Cycle of *Chilo infuscatellus*
The life cycle of *Chilo infuscatellus* is complete metamorphosis, consisting of four stages: egg, larva, pupa, and adult.
Egg Stage
The female moth lays eggs in masses of 200-300, usually on the underside of sugarcane leaves, covered with a brownish scale-like substance. Eggs hatch in 5-7 days.
Larval Stage
The larval stage is the most destructive. The newly hatched larvae are pale yellow and bore into the stalk within 24-48 hours. They pass through five instars (developmental stages). Larvae feed within the stalk, creating tunnels and causing ‘deadheart’ in young plants and reducing sugar content in mature plants. The larval stage lasts for 20-30 days.
Pupal Stage
The mature larva pupates inside the stalk in a silken cocoon. The pupal stage lasts for 7-10 days.
Adult Stage
The adult moth emerges from the pupal case. It is a small, greyish-brown moth with a wingspan of 25-30 mm. Adults are nocturnal and feed on nectar. The female moth lays eggs, completing the life cycle. The entire life cycle takes approximately 60-90 days, depending on environmental conditions.
Damage Caused by *Chilo infuscatellus*
The sugarcane stalk borer causes significant damage to sugarcane crops at various stages of growth:
- Deadheart: In young plants, larvae bore into the growing point, causing the central shoot to dry up, resulting in ‘deadheart’.
- Top Shooting: Damage to lateral buds leads to the development of multiple shoots, reducing the overall yield.
- Stalk Tunneling: In mature plants, larvae tunnel through the stalk, weakening it and reducing sugar content. This also makes the stalks susceptible to fungal and bacterial infections.
- Reduced Yield & Quality: Infestation leads to a reduction in cane weight, sugar recovery, and juice quality.
Control Measures
Integrated Pest Management (IPM) strategies are crucial for effective control of *Chilo infuscatellus*:
- Cultural Control:
- Early sowing of sugarcane to avoid peak pest population.
- Removal and destruction of stubbles after harvest to eliminate overwintering larvae.
- Proper drainage to avoid waterlogging, which favors pest development.
- Biological Control:
- Use of egg parasitoids like *Trichogramma chilonis* and *Telenomus remus*.
- Application of biopesticides like *Bacillus thuringiensis* (Bt).
- Conservation of natural enemies like spiders and predatory beetles.
- Chemical Control:
- Application of systemic insecticides like chlorpyrifos or carbofuran, but judiciously and following recommended dosages.
- Use of granular insecticides applied to the soil at the time of planting.
- Resistant Varieties:
- Planting of sugarcane varieties resistant to borer attack, developed through breeding programs.
- Pheromone Traps:
- Use of sex pheromone traps to monitor pest population and disrupt mating.
Conclusion
*Chilo infuscatellus* remains a significant threat to sugarcane production in India. Effective management requires a holistic approach integrating cultural, biological, and chemical control methods. The development and deployment of resistant varieties, coupled with judicious insecticide use and the promotion of biological control agents, are essential for minimizing losses and ensuring sustainable sugarcane cultivation. Continuous monitoring and research are crucial to adapt control strategies to evolving pest populations and environmental conditions.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.