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Rota Pests and Diseases
Noni Insect Pests on the Island of Rota
Several insect pests of noni were observed at the Bird Sanctuary on the island of Rota in the Northern Marianas islands of Micronesia in 2002. Some of the damage we observed was significant. The Bird Sanctuary is a protected habitat that is not really managed, and the noni population there is a wild population that hosts a thriving community of insects, both plant-parasitic and beneficial.
  1. Loopers and cushiony scale
  2. Weevils and rose beetles
  3. Stem-boring moth/Lepidoptera
  4. Leaf miners
1. LOOPERS (and cushiony scale)

Noni leaves in Rota may be attacked by green caterpillars known as loopers. The pest in question on Rota is probably the green garden looper.
Noni leaves attacked by loopers
Looper feeding injury. The green garden looper prefers to feed at noni leaf margins, leaving severely diminished leaves with irregular margins. For some leaves, almost all leaf tissue is gone, leaving only the primary veins. The white objects on the leaves in the photograph are scale insects (one of the cushiony scale species).
young looper on stem
Young looper on stem. Can you find the young, yellowish-green looper in this image? It is on the noni stem, near point of attachment of the leaf petioles. They can grow to be much larger than this well-camouflaged young caterpillar.
looper damage
Looper damage. Marginal chewing damage on noni leaf (center) associated with loopers. A brown leaf spot symptom, perhaps a fungal disease or leaf injury, is visible at upper right.
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In the Bird Sanctuary on Rota, noni leaves with numerous small, irregular holes were observed. We believe these holes are the result of feeding by weevils on noni foliage, and/or rose beetles. The weevil and rose beetle populations in the area were quite large.
irregular shot hole pattern
An irregular shot hole pattern is associated with insect feeding, perhaps weevils or rose beetles.
windowing effect
Windowing effect on affected noni leaf associated with noni weevils (adaxial leaf surface).
windowing effect
Windowing effect on affected noni leaf associated with noni weevils (abaxial leaf surface).
mature weevil
Mature weevil associated with foliar damage to noni. (species undetermined)
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A severe twig and stem dieback symptom was observed at the Bird Sanctuary in Rota. The damage is associated with an insect, a Lepidopteran larvae, probably a moth that lays its eggs at the tips of stems, twigs and branches, or fruits. When the eggs hatch, they feed within stems tissues, hollowing out the noni stems and killing that part or the branch or organ.
Twig and branch dieback
Twig and branch dieback after the moth larvae hatched and fed within the growth tip of the stem.
blackened insect frass
Blackened insect frass (excrement) at the apical meristem of a noni stem. Moth larvae are inside the stem, devouring the soft tissues of the inner noni stem. Adult female moths lay their eggs in the apical meristem region of vertical stems and lateral braches, as well as in noni fruit.
blackened inner stem
Noni stem dissected to reveal the blackened inner stem tissues caused by feeding of the moth larvae.
Several larvae of the stem-boring moth
Several larvae of the stem-boring moth are exposed and visible when the affected stems are opened. The feeding damage can cause noni stems to die back.
Necrotic and blackened young noni fruit
Necrotic and blackened young noni fruit and re-sprouting stem, associated with feeding activity of moth larvae.
Severe scarring and black pitting of Morinda citrifolia
Severe scarring and black pitting of Morinda citrifolia may result from the feeding activity of the larvae of an unidentified stem-boring moth.
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leaf miners
Leaf miners leave a whitened trail or tunnel of destroyed noni leaf tissue.
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Last Updated on December 7, 2006