Cicadas in Silent Valley National Park
- Blogs
- September 15, 2025
Syllabus: GS3/ Environment
In News
- Unique species of cicadas (insects known for their loud buzzing sounds) were recently documented in Silent Valley National Park, Kerala by researchers.
Background
- Cicadas are insects belonging to order Hemiptera (true bugs).
- Known for:
- Acoustic signalling (mating calls by males).
- Some species follow periodical emergence cycles (13 or 17 years in North America).
- In India → cicadas show high diversity in Western Ghats & North-East India.
Silent Valley National Park
- Location: Palakkad district, Kerala (Nilgiri Biosphere Reserve).
- Declared NP: 1984 → Prime example of evergreen tropical forest.
- Known as “the rainforest without silence” due to insect sounds, esp. cicadas.
- Rich in endemism: lion-tailed macaque, Malabar civet, Nilgiri langur.
Ecological Importance of Cicadas
- Indicator species → reflect forest ecosystem health.
- Nutrient Cycling → after death, bodies enrich soil.
- Food web → prey for birds, reptiles, mammals.
- Soundscape ecology → contribute to forest acoustic diversity.
Significance of Findings
- Taxonomic diversity in cicadas of Silent Valley remains under-studied.
- Adds value to biodiversity hotspot status of Western Ghats (UNESCO).
- Helps in conservation prioritisation.
Challenges
- Habitat destruction (deforestation, plantations).
- Climate change affecting emergence cycles.
- Sound pollution interfering with communication signals.
Do You Know?
- Cicada lifecycle → long underground nymphal phase (feeding on root sap) followed by short adult phase for reproduction.
- The buzzing sound is produced using tymbal organs in males.
- The name “Silent Valley” ironically comes from absence of cicadas in certain tracts (early British reports), but later surveys confirmed rich diversity.