Red ring of coconut palms

Definition

A lethal phytoplasma disease of coconut palms (Cocos nucifera) and other palms, characterized by a distinctive orange-to-red necrotic band in the trunk cross-section 2–4 cm below the stem apex. The disease is transmitted by the palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae) and related Rhynchophorus species, which acquire the phytoplasma during larval feeding and transmit it as adults.

Etymology

Example

In Trinidad and Tobago, the red ring of coconut palms spread rapidly through coastal plantations during the 1980s; control efforts targeted the vector weevil using pheromone-baited traps and removal of infected trees to prevent adult weevils from acquiring the phytoplasma and spreading it to healthy palms.

Synonyms

• red ring disease
• lethal yellowing-related red ring syndrome

Related Terms

• phytoplasma
• Rhynchophorus ferrugineus
• vector-borne plant disease
• lethal yellowing
• palm weevil
• Cocos nucifera

Usage Notes

The term refers specifically to the disease syndrome and its diagnostic internal trunk symptom, not to the phytoplasma agent itself (Candidatus Phytoplasma palmae, subgroup 16SrIV-D). Distinguished from lethal yellowing, another phytoplasma disease of palms with different symptoms and vectors. Field diagnosis relies on the characteristic red ring in trunk sections; molecular confirmation requires PCR detection of the phytoplasma. The disease is economically significant in the Caribbean, Central America, and parts of South America.