- Common Insect Problems on Plumeria - and their treatments -
Overview Plumerias have no significant bug problems in Arizona. However during the cooler months and under certain conditions the following insects may attack your plumeria leaves. A healthy plumeria will survive these insect attacks with only cosmetic damage. But if the insects get out of control your plumeria might decide to go dormant for awhile before popping out leaves just to make you worry.
Spider mites ( Tetranynchus urticae Koch )
are tiny spider like insects that may or may not form fine webs
on the leaf undersides and branch tips. They suck plant sap causing
pale, speckled, and yellowish leaves.
One of the major pests associated with plumeria is the sixspotted spider mite, (Eotetranychus sexmaculatus)
Suspect the possible presence of sixspotted web-spinning spider mites if early season plumeria growth shows deformed leaves, abnormally forming bloom clusters, blistered tissue, necrotic spots on leaves, leaf drop, or shoot tip dieback.
Other symptoms suggesting a mite problem are fully developed leaves with a yellow stripe down the midrib or bronzing on the upper leaf surface, webbing between the midrib and upper leaf surface, or webbing between the base of the leaf petiole and the plant stem.
If left unchecked spider mites will damage and stunt plumeria growth.
They are most common Arizona during the spring and fall when dry conditions exist and slower plant growth allow them to attack the leaves.
Note: Spider mites thrive in warm, dry,
and still areas.
The use of fans strongly discourages spider mites.
1. Keep the growing area clean and free
of fallen leaves. (Keep the Greenhouse area as clean as possible)
2. Carefully remove and place badly infected
leaves into trash bags.
3. Blast all existing leaves clean with
a water hose.
4. Move plants into a more open and sunny
5. Improve the air circulation in greenhouse
area, and as weather permits remove plants, and blast them clean and free
of all mealybugs and mites.
6. Horticultural Oils : You can use a horticultural oil such as Neem Oil to treat spider mites. Apply as directed to the top and undersides of leaves. Use only in the cool and winter seasons as heat and direct sun can burn leaves in summer.
Mealybugs ( Planococcus citri (Risso) )
are scale insects that live under
white, woolly masses, and suck sap and nutrients from plants.
Mealybugs are an insect that forms a white cotton like substance and they love buds, creases and creaves in plants. The mealy bugs secret a sticky honeydew substance from sucking the leaves. This can lead to the formation of Sooty mold on the leaves.
seem to love a few varieties of plumeria, while they leave others growing close by
unaffected. As Mealybugs suck on the plumeria leaves they tend to cause the leaves
to grow warped and mis-shaped.
If left unchecked mealybugs can totally
stunt a plumeria's growth. Plumerias usaully recover after the bug
are brought under control.
7. The best thing to use on them are oil sprays. My favorite is Ultra Fine Neem oil which coats and suffocates them. You can also use rubbing alchol. It will kill them on contact but does not have an residual effect.
Scale insects ( Homoptera: Coccidae )
are hard, round, shell-like insects adhere to stems
and leaf undersides. Most scale insects are parasites of plants, feeding on sap drawn directly from the plant's vascular system. As they suck the plants juices they can
cause stunted growth or cause distorted growth.
Scale insects can be serious pests on all types of woody plants and shrubs. They are so unusual looking that many people do not at first recognize them as insects. This is because they are hidden under a disk-like or waxy covering, and lack a separate head or other recognizable body parts. They often colonize plants without being easily detected and, by the time they are noticed, the host plant has been weakened and may be dying back.
We hope you learned information on the common Insects that can attack your plumerias. These pests can attack your plants even here in Arizona, especially during the cooler months and under certain conditions. Remember stressed tree are more suspectiable to insect attacks, so keeping your trees healthy is a key to your success.
We wish you happy and healthly growing plumeria trees.