The Hidden Diversity of Soil Insects in Batu, East Java
Imagine a parallel world beneath every step we take—a world inhabited by microscopic ecosystem engineers that maintain nature's balance. In Batu, East Java, two neighboring landscapes—the lush Arboretum Sumber Brantas and the neatly arranged potato farmlands—become the stage for an incredible story about soil insect diversity. This 2016 research reveals how human disturbances alter complex underground communities, with profound implications for ecosystem health and sustainable agriculture .
Soil insects—organisms that spend all or part of their lives in the soil—are not passive inhabitants. They are ecosystem architects with critical functional roles:
Break down dead organic matter (e.g., some beetle species)
Break down complex compounds into absorbable nutrients (4 families in Arboretum)
Control natural vegetation (6 families in Arboretum vs 1 in potato fields)
Maintain balance of other insect populations (5 families in Arboretum vs 2 in potato fields)
A key parameter where H' > 1 indicates a healthy ecosystem, while H' approaching 0 indicates severe disturbance. The Arboretum and potato fields show extreme contrast: 0.595 vs 0.224 .
The distribution of functional groups reveals ecosystem health. The Arboretum maintains balanced groups while agricultural land shows significant reduction in predators and decomposers .
This April-June 2016 research used a quantitative descriptive approach with standardized field exploration methods:
30 traps at each location, activated for 24 hours to capture surface-dwelling insects.
Specimens photographed at UIN Malang's Optics Lab, matched with Bugguide.net and reliable literature.
Soil samples tested at Brawijaya University's Soil Lab for 10 parameters including temperature, moisture, pH, organic matter, phosphate and potassium.
| Parameter | Arboretum | Potato Farm |
|---|---|---|
| Number of Families | 16 | 7 |
| Total Individuals | 9,266 | 1,573 |
| Herbivore Families | 6 | 1 |
| Predator Families | 5 | 2 |
| Diversity Index (H') | 0.595 | 0.224 |
| Soil Parameter | Affected Insects | Correlation |
|---|---|---|
| Organic Matter | Gryllidae 1 | 0.552 (Medium) |
| N-Total | Gryllidae 1 | 0.527 (Medium) |
| Phosphate | Gryllidae 2 | 0.467 (Medium) |
| pH | Forficulidae | 0.366 (Medium) |
| Moisture | Gryllidae 2 | 0.329 (Low) |
| Tool/Reagent | Critical Function | Example Usage |
|---|---|---|
| Pitfall Trap | Passively captures surface-dwelling insects | 30 traps/site filled with 70% ethanol |
| Soil Corer | Takes layered soil samples | Analysis at 0-20 cm depth |
| BugGuide.net | Online morphological identification database | Matching Gryllidae specimens |
| Past 3.12 Software | Ecological index analysis (H', dominance) | Calculating H' differences |
| Portable Soil Test Kit | Quick measurement of pH, moisture, temperature | In-situ monitoring of key parameters |
Reduction of predator families (from 5 to 2) in potato fields disrupts natural pest control. The result: increased pesticide dependence—a factor that worsens the cycle .
Low correlation between organic matter and decomposer insects in farmland (unlike Arboretum) shows soil function degradation. Without decomposers, nutrient cycles are impaired—affecting long-term productivity .
Gryllidae subfamilies 1 and 2 emerge as resilience indicators with medium correlations to organic matter, N-total, and phosphate. Their presence could serve as an early warning of soil health in agroecosystems .
Regenerative agriculture based on these findings can be implemented through:
Straw/animal manure compost to attract decomposers and improve soil structure.
Belts of native plants along field edges as predator habitats and ecological corridors.
Using cricket populations as simple bioindicators of soil health and ecosystem balance.
The striking contrast between Arboretum Sumber Brantas and Bumiaji's potato fields isn't just about numbers—it's a story of resilience and fragility. The diversity index values of 0.595 vs 0.224 prove: when we simplify landscapes, we impoverish the underground world that sustains life. Soil insects may be invisible, but they are the silent guardians of balance who ultimately determine the future of ecosystems—and our agriculture .