How was the 2014 cocolisap outbreak stopped?

Biocontrol. The lab-reared parasitoid wasp Comperiella calauanica was released across Calabarzon, parasitizing the scale insect Aspidiotus rigidus and suppressing the outbreak to manageable levels by 2016.

Cocolisap · 2014 outbreak

One scale insect, two million palms.

Coconut scale (Aspidiotus rigidus) jumps tree to tree across a Calabarzon grove. Release the parasitoid wasp at the right moment — and watch the SIR curve bend.

Day 0 grove healthy · ready

Healthy (S) Infested (I) Recovered — wasp (R)

Infested

0.3%

3 palms

Recovered

by biocontrol

Copra revenue loss

₱0.0M

R₀ ≈ 3.0 · need >70% parasitized to halt

Epidemic curve · S / I / Rpeak —

S I R wasp release

Transmission rate β0.60

Wind-borne scale crawlers per infested neighbour. Higher β → faster grove-wide spread.

Biocontrol release delay30 days

Comperiella calauanica wasp, lab-reared at UPLB. Real 2014 deployment took ~60 days to scale across Calabarzon.

How to use

Each cell is one coconut palm. It runs the classic SIR states: Susceptible → Infested → Recovered. Drag β to set how aggressively the scale jumps between neighbours, and set when the wasp is released, then press Play. The release day appears as a dashed marker on the curve — watch infested palms turn gold as the parasitoid takes hold.

The 2014 outbreak

Coconut scale insect (Aspidiotus rigidus) was first detected in Calabarzon around 2010. By 2014 it had infested an estimated 2.1 million coconut palms, costing roughly US$80M in copra revenue per year at the peak.

Control came not from pesticide but from biology: the parasitoid wasp Comperiella calauanica, lab-reared at UPLB, was released at mass scale. By 2016 the outbreak was suppressed to manageable levels.

SIR dynamics in trees

Palms are stationary hosts and the vector is wind, so the Kermack–McKendrick SIR model fits unusually well. S → I happens at rate β × infested neighbours; I → R happens once the parasitoid wasp has been released and reaches a tree.

For cocolisap R₀ ≈ 3–4. To halt spread you must "vaccinate" — here, parasitize — more than 70% of hosts. The PCA achieved this by 2016.

Citations

Watson et al. (2015) — Aspidiotus rigidus outbreak in the Philippines, Florida Entomologist 98, 1071.
PCA (2014) — Philippine Coconut Authority emergency program report.
Almarinez et al. (2015) — Comperiella calauanica n. sp., parasitoid wasp description, ZooKeys 504, 47.
Kermack & McKendrick (1927) — original SIR model, Proc. R. Soc. A 115, 700.
DA-BPI (2016) — Department of Agriculture biocontrol deployment summary.

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