Moth & weevil
Paysandisia archon 🔍: This is the palm moth, also known as the palm borer moth or palm castine. It is the only species in its genus. Its caterpillar feeds on palm trees, hence the name "palmivore moth," against which Vigipalm® provides protection. More information is available on the INPN website.
Rhynchophorus ferrugineus 🔍: This is the red palm weevil, also called the coconut palm weevil, known for the significant damage it causes to coconut plantations. More dangerous than Paysandisia archon, it has earned the nickname "palm tree killer." More information is available on the on the INPN website.
The palmivore moth and the red palm weevil have distinct attack methods but share some similarities.
Common features:
Target: Both pests attack palm trees, causing significant damage that can lead to their death.
Larvae: The larvae (caterpillars) of both insects feed on the internal tissues of the palm, tunneling galleries that weaken the tree’s structure.n cause irreversible damage, sometimes requiring the felling of infested palms to prevent further spread.
Impact : Both pests can cause irreversible damage, sometimes requiring the felling of infested palms to prevent further spread.
Differences :
Mode of attack:
Palmivore moth: Females lay their eggs mainly at the base of the palm fronds, on the petioles, using a posterior organ called an ovipositor; the larvae feed on the soft tissues of the palm’s core, causing significant internal damage. Only the larvae are harmful.
Red palm weevil: Adult females lay eggs at the base of the fronds but also in wounds on the trunk (stipe), using their rostrum (a beak-like organ) to pierce palm tissues and deposit eggs; larvae develop inside the trunk, destroying vascular tissues and blocking sap flow. It is more destructive than the palm moth because, in addition to its larvae, it attacks the palm as an adult. Due to its high harmfulness, control of the red palm weevil is mandatory across the French territory by ministerial Decree of June 25, 2019.
Visible external symptoms (non-exhaustive):
Palmivore moth: Perforated fronds (aligned holes, torn appearance), deformed fronds, apical deviation causing asymmetry in solitary palms, brownish sawdust at the base of fronds or on the trunk, presence of cocoons and chrysalises, collapse of the palm heart (advanced attack), and presence of moths in summer.
Red palm weevil: Sagging fronds and progressive yellowing, absence of the central tuft, presence of loose fibers and internal galleries in the trunk, oozing viscous liquid with a foul odor due to tissue fermentation, weakened terminal bud, presence of white larvae and fibrous cocoons at the base of fronds, and presence of adult weevils visible around the palm from spring to autumn depending on the climate. At an advanced stage, a characteristic noise produced by larval mandibles may be heard.
Life cycle:
Palmivore moth: Long life cycle, with larvae remaining inside the palm for several months, up to 18 months depending on environmental conditions.
Red palm weevil: Shorter life cycle, 3 to 7 months depending on environmental conditions, allowing rapid spread.
Adult size:
Palmivore moth: Large moth with an 8 to 11 cm wingspan, females being larger than males.
Red palm weevil: 2 to 4 cm long and 0.8 to 1.6 cm wide.
Why are palms targeted?
Availability: Palms are commonly planted in urban heat islands, parks, and gardens, making them easily accessible to pests.
Structure and tissues: The soft, nutrient-rich tissues of palms provide an ideal environment for larval development.
Environmental conditions: Palms often grow in warm climates favorable to pest reproduction and development.
Lack of natural defenses: Many palms lack effective defense mechanisms against these pests.
Absence of natural predators.
Lack of awareness: Insufficient public awareness regarding prevention and detection contributes to their spread.
Lack of collective control measures.
It is crucial to regularly monitor palms and adopt appropriate control measures and strategies to protect them against these destructive pests.