Palm aphid

This aphid is unusual in that the female becomes sedentary like a scale, and forms a distinctive ring of white wax around its body. These aphids heavily infest young leaves and excrete honeydew upon which sooty mold will grow. They are sometimes tended by ants. Dimethoate (Cygon) and Orthene have provided some chemical control. Insecticidal soaps have also effectively controlled the sucking insects. Lady beetles are an excellent biological control, and spraying should be avoided if these aphid predators are observed on the infested palm.

Magnolia white scale

In great variety, do turn up on palm leaves from time to time, including thread scale, magnolia white scale, oyster scale, Florida red scale and others. The hard shell of many scales reduces the effectiveness of many chemicals. Dimethoate (Cygon) has worked reasonably well on a variety of these troublesome pests. Supracide is currently considered by many growers to be the most effective chemical control. Although a number of beneficial insect predators for scales are available from commercial firms dealing in predatory insects, there is not a great deal of information on the relative effectiveness of these scale `eaters’.
Florida red scale

Spider mites are particularly a problem on greenhouse grown indoor palms, and on many Chamaedorea species. The predatory mite species, Phytoseiulus perrsimilis has been very successfully used to control two-spotted mites (Tetranychus urticae) on palms in the greenhouse environment and interiorscapes as well. Many chemical miticides also work successfully.

Coconut fruits disfigured by coconut mites

This tiny mite feeds on the husk of coconut fruits, causing mostly cosmetic damage but sometimes premature fruit drop as well.

The larvae of this moth has been a destructive pest on a number of palm species in tropical areas, especially Chamaedorea species and arecas. Though more a palm production pest, infestations of landscape palms have occurred. The caterpillar tunnels through the stems of the palms. Lindane and Sevin have had some success in control, and Dipel may be effective as well. Parasitic nematodes have also been fairly effective in controlling infestations of this insect.

Damage caused by palm leaf skeletonizer

The caterpillars of this small moth feed on the upper and lower leaf surfaces of many palms, producing large quantities of `frass’ (fibrous excrement) that is often the first conspicuous sign of an infestation. The tissue between the veins or ribs is usually their preferred food, but they will also feed on the leaf stems, disrupting the vascular tissue and causing the death of the entire leaf. No one control has been reported to be supremely effective. Sevin, Lindane and the biopesticide Dipel 2X have all had some success.

Royal palm bugs

A troublesome pest of royal palms (Roystonea species) in Florida and the Caribbean. Infestations in South Florida tend to increase in the spring and summer following a particularly mild winter. This tiny bug feeds on the young leaves of the palms, often getting in between the folds of an emerging leaf. When the leaf unfolds it appears scorched and brown, and usually fails to mature. A foliar spray with dimethoate (Cygon) has been found to be the best control, though application to very tall royal palms can be problematic.

Damage caused by royal palm bug

Adult female palmetto weevils

Large beetles that are drawn to stressed palms in the subtropical Deep South. They most frequently attack cabbage palms (Sabal palmetto) and Canary Island date palms (Phoenix canariensis), but have been reported on Mexican fan palms (Washingtonia robusta), Bismarck palms (Bismarckia nobilis) and latan palms (Latania spp.). Adult females lay eggs in the leaf bases of the crown, and the large larvae quickly tunnel into the heart, destroying the palm. The crown of affected palms frequently topple over or `deadhead’. All efforts should be made to reduce transplant stress on susceptible species. A preventative spray of either Lindane or Dursban, applied at and again a few weeks after installation, has shown some success in keeping palms free of infestation. A related species, R. palmarum, occurs in Central and South America and the Caribbean and spreads a destructive namatode that causes red ring disease in coconuts and African oil palms.

`Deadheading' of cabbage palm (Sabal palmetto) caused by palmetto weevils

Larva of palmetto weevil and typical feeding damage

Stinging saddleback caterpillar

Feed on the leaves of palms from time to time. Small infestations can be dealt with mechanically without recourse to pesticides; however, if these insects are on palm foliage in force, they can very quickly do appreciable damage, completely defoliating a young palm in as little as 1-2 days. The biopesticide Dipel 2X is effective on a wide variety of caterpillars. Dursban or Lindane will control grasshoppers if treatment is applied when the insects are young.