Oleander Caterpillars: Description, Damage, Caterpillar Control

Oleander Caterpillar

Description, Damage and Control

Oleander caterpillars feeding on Oleander shrubs can cause damage that ranges from minor to extreme. Areas where the damage is severe include Florida, coastal regions of Alabama and southern Georgia.
This pest of Oleanders can actually be found in any locale where the Oleander plant flourishes but has not been seen as a pest in California.
In most areas where this caterpillar has been found, its damage has been noted as slight to moderate but in other areas (especially Florida and coastal region of Alabama) the damage can be quite severe.

In light to moderate caterpillar infestations, damage to leaves of the Oleander shrub is seen as small holes chewed between leaf veins, progressing to complete skeletonized leaves. In severe cases this caterpillar can strip the Oleander shrub of its leaves and small stems in a short time period. However, this shrub is very sturdy and many customers tell us that their shrubs rebounded after being ravaged by the offending worm.
Damage to the shrub is explained in the life cycle of the Oleander Caterpillar. Severity of damage to your shrubs and frequency of oleander caterpillar infestations will determine which methods of control to take.

Description, Life Cycle of Oleander Caterpillar, Wasp Moth

Oleander caterpillars are the immature stage of a moth called the Polka Dot moth. The Wasp moth gets its name from its appearance which does resemble that of wasps more than moths. This is a beautiful moth that has blue/green coloration on its wings. The wings and body both have contrasting white dots, hence the common name of «polka-dot moth.»
The young caterpillars hatch from eggs laid by the adult Wasp moth. The first meal of this caterpillar is its egg shell.
After its emergence from the egg, the tiny Oleander caterpillar begins feeding on its host plant. It is protected from the toxins of the Oleander by its feeding habits. In its first instars this pest feeds only on the leaves, avoiding the highly toxic stem and leaf veins. Oleander toxins are highly concentrated in the plant’s vascular system. As noted by Daniel E. Mullins, Extension Agent for Santa Rosa County, Florida, the damage to the Oleander corresponds with the specific caterpillar instar (stage).
The smallest will begin to feed on the underside of the Oleander leaves. As they grow and transform to larger instars these caterpillars readily consume all of the leaves except for the veins, leaving a characteristic skeletonized appearance. As the caterpillar gets larger, it is capable of cutting through the actual leaf stem which cuts off the flow of toxic sap.
The feeding habits of different larval stages are what allow the caterpillar to survive feeding on a plant that most pests must avoid.
The pupal stage is the final one before the adult moth emerges to complete the cycle. These pupae are often found on groups or pupal clusters. There have been numerous reports of these clusters creating quite a mess under the eaves of homes or buildings that are near or adjacent to the Oleander plants.

Deciding on which control method or methods to take will depend on several factors, including severity of the problem, any history of severe problems with Oleander caterpillars in your garden, controlling pests in a butterfly garden and other situations. Spraying for caterpillars (using botanical sprays or an insecticide spray) is a last resort for many gardeners. We have seen many instances of severe infestations in the Gulf Coast region where pesticide use is a must, if one desires to keep Oleander shrubs in their landscaping plans.

At first sign of caterpillar infestation, hand picking the caterpillars from the shrub is your best bet. Drop the Oleander caterpillars into a bucket (or other container) that contains a strong soap solution. The soapy water should kill the caterpillars that cannot escape the container.
As the situation deteriorates you will begin to see more damage to the leaves and the damage will probably be noticed in higher levels of foliage.
As the sheer number of caterpillars increases, clip off stems and leaves that are infested. Remember that the sap of the Oleander is toxic and any vegetation that is pruned should be disposed of in a safe manner. Place pruned vegetation in a plastic garbage bag or leaf bag and dispose the bag properly. Do not allow horses or other grazing animals to feed on this vegetation! You should also wash your hands thoroughly after handling the plant’s parts.

When caterpillars are feeding on very tall shrubs, selective pruning may no longer be a sensible option. It is at this point that you must decide whether to replace the Oleanders with another ornamental plant or spray the caterpillars with an effective spray.

After all mechanical means of control have been exhausted you may have to use a spray to kill the Oleander caterpillars. There are two basic spray types to consider: botanical and synthetic pyrethroids.
BT (Bacillus thuringiensis) is a material that kills caterpillars and is often used in vegetable or flower gardens. The plus side of using a BT spray is that it only effects caterpillars and will not harm desirable butterflies or helpful insects such as lady bugs. If BT is used, the predators of the Oleander caterpillar (fireants, predatory stink bugs) are not harmed. This is a good product to use if you have Oleander shrubs in a butterfly garden. Continuous spraying will probably be necessary in order to kill the different generations of caterpillars that are usually present at any given time.

Many people (including lawn care professionals) in the coastal areas of Florida and Alabama have turned to synthetic chemicals to eliminate Oleander caterpillars from their tall Oleander shrubs.
Over the past few years there have been some surprises in which chemicals are effective against this pest. It was originally thought (with good reason) that systemic products such as Acephate (also called Orthene) should easily eliminate any caterpillar that is feeding on ornamental plants. The Oleander caterpillar rarely responded to Acephate. This caused many turf and ornamental specialists to turn to Talstar for a good spray. When used against a wide variety of household, turf, tree and ornamental pests Talstar has given a great level of control for long periods of time — while using a very small amount of active ingredients to get the job done.
When heavily infested shrubs were sprayed with a solution of Talstar, the caterpillars were knocked down but only to return the next day.
Through much trial and error, professional strength Permethrin products proved to be the best for controlling or eliminating Oleander caterpillars. Permethrin products are used to exterminate Oleander caterpillars.
In heavy or stubborn infestations, two or three applications might be necessary.
These applications should be made at about 10 to 14 day intervals to effectively kill the different generations of Oleander caterpillars that are probably present.
Use a hose-end sprayer to apply Permethrin to large or tall stands of Oleander shrubs. One to two ounces of Permethrin concentrate per gallon of water will yield a solution that will kill Oleander caterpillars.


Caterpillars & Birch Trees

By: Nancy Wagner

21 September, 2017

Several caterpillars use birch trees as sources of food during their larvae stage. The caterpillars eat the leaves of the trees while they grow big enough to go into their pupate stage before emerging as moths.


The birch leaf roller, Epinofia solandriana L, is a small caterpillar commonly found in south-central Alaska. The insect gets its name thanks to the older caterpillars that start to roll the leaves as they feed on them. Forest tent caterpillars may also feed on birch trees while building nests to live in while they eat and grow bigger.


While leaf rollers cause little long-term damage to birch trees, the tree can become unsightly. Forest tent caterpillars also cause little permanent damage, but they can cause the tree to produce smaller leaves to replace the ones the caterpillars ate. Tree growth rates can decrease because of the defoliation, causing the trees to become more susceptible to other pests.


Natural predators, including the parasitic fleshfly, help control the insects by eating forest tent caterpillars in their cocoons. Insecticides may be required if birch leaf rollers infest a tree for more than two years in a row.


Birch moth, beautiful and dangerous pest

The peppered moth family of pests numbers fifteen thousand species, the name was obtained as a result of the caterpillar movement patterns.

Butterflies do not have a bright color, the color of the wings is often very close to the colors of the habitat, insects firmly press the wings and body to the surface of trees and merge with the background.

The pest can cause great damage to forest plantations and gardens, therefore it is recommended to take measures to destroy it as early as possible.

Birch Moth

Insect is considered one of the most common species, the length of the wings can reach forty millimeters, wingspan — thirty to forty millimeters. The wings are distinguished by a gray tinge with broken stripes, dots and small bright spots.

Insect is considered one of the examples of moving selection associated with industrial melanism. Until the middle of the 20th century. individuals of this species were distinguished by a light gray color; as industrial production developed, the color of insects began to darken, as did soiling trees.

Damage to plants is also caused by the moth caterpillars., on the back of insects are elevations that visually resemble warts, the central part is green, with brown spots at the ends.

Butterflies are found from mid-June to August, often flying at night. All moths differ in their habitat, wing color, pupation site, body shape, and time of appearance.

Known species of moth are also considered a large green, gooseberry, winter moth, male winter individuals have sufficiently developed wings, the time of the appearance of butterflies is in late autumn.

What plants hit

The moth eats the leaves of fruit trees (plum, cherry, Apple tree) it also strikes maple, birch, willow, oak, beechit is also worth fearing turn and roses.

How to fight

It is recommended to fight females with underdeveloped wings with gluey trapping paper belts, on the surface of which non-drying garden glue should be applied.

This will help prevent insect females from crawling onto treetops for the purpose of laying eggs. They should be placed on the upper and lower parts of the trunk, insects accumulated on the belts and their eggs to be destroyed.

Late autumn is necessary to dig the ground in the area near the ground, the digging of the soil should also be carried out between June and July, when the larvae pupate, which will prevent the appearance of insects into the world.

Biological methods of protection show high efficiency in the fight against moths, one of them is the creation of acceptable conditions for the life of the enemy and the pest — takhin flies, riders, to attract them, it is recommended to plant umbrella plants on the site (dill, celery, carrot).

Treatment of plants before or at the beginning of flowering with insecticide preparations will also help to get rid of the moth.gomaline, lipocide, dendrobatsilin).

Other methods of struggle:

  1. mechanical collection and destruction of caterpillars and their nests;
  2. regular cleaning of bark from lichens and mosses, whitewashing trunks;
  3. deep soil loosening in the near-bed space and between the rows;
  4. spraying with biological preparations and pesticides; it is carried out during the period of mass creeping out of the caterpillars.

Birch moth is considered one of the most common pests, the insect affects trees, eats leaves, a large number of insects can completely destroy the crown of a tree. As countermeasures, it is recommended to use agrotechnical, biological methods, as well as a mechanical method. The choice of control method depends on the time of year, the degree of pest damage to the trees, the characteristics of the site, etc.


Gypsy Moth: Facts, Life Cycle, Damage and Control

Just as trees begin to leaf out in the spring season, gypsy moth caterpillars are hard at work, eating those brand-new leaves.

As gypsy moths strip trees of their leaves, trees become weak and susceptible to other injuries.

When it comes to tree pests, the best thing we can do is learn more, then take proactive steps to control them. Here are all the gypsy moth facts you need!

Gypsy Moth Caterpillar: The Damage It Does and How to Control It (Even in Massachusetts in 2018)

Where did the gypsy moth come from?

Originally from Europe and Asia, gypsy moths made their debut in the U.S. more than a century ago. In the late 1860s, Leopold Trouvelot transported a trove of moths to his Boston home.

Soon after, the first gypsy moth outbreak was around 1890.

How many gypsy moths are expected in Massachusetts in 2018?

As the birthplace of the U.S. gypsy moth outbreak, Massachusetts trees are especially affected by the insects.

The good news is that the moths are slowing down this year. The University of Massachusetts reported that nearly 90 percent of gypsy moths died last year. The rain in 2017 activated a native soil fungus that reduces the gypsy moth population.

But that doesn’t mean gypsy moths are gone for good. Defoliation is expected in Essex, Hampden, Hampshire, Norfolk, and Worcester Counties. But, Massachusetts trees won’t experience the extreme rate of leaf loss they have in past years.

What’s the life cycle of the gypsy moth?

Gypsy moths go through four stages.

  1. Adult moths lay eggs toward the end of summer.
  2. The following spring, usually around late April or early May, young caterpillars emerge. That’s when they begin feeding on all your new tree leaves!
  3. After eating your trees for about a month, the caterpillars rest in their pupal cases.
  4. Sometime during July or August, they emerge as white or brown-winged moths. They get ready to lay eggs, which starts the whole process over!

What kind of damage does the gypsy moth do?

Gypsy moth caterpillars partially or entirely strip trees of their leaves. They prefer oaks, especially white and chestnut. But they’ll also eat alder, aspen, basswood, birch, hawthorn and willow trees.

Then, because the tree is weak from the loss of its leaves, it becomes vulnerable to other problems.

“Like people, when [trees] get weak, they’re more susceptible to certain pests and diseases. The year of the drought, we lost a lot of trees or they were under stress,» said Jim Doyle of Hartney Greymont, a Davey company in this Wicked Local Dedham story.

How can I control the gypsy moth?

The best advice? Be proactive. Here’s what to do:

  • If you have damaged, compromised, or beloved trees in your landscape, be prepared to treat those trees early if gypsy moth injury is expected. Talk to your arborist about applying a well-timed insecticide treatment. An ounce of prevention goes much further than no prevention at all.
  • Consider adding a tree band in late May. These trap gypsy moth caterpillars as they hike up and down your tree.
  • Fertilize your tree to improve its ability to recover from gypsy moth damage.
  • Water your tree on dry days in the summer to prevent any added stress from drought.



Originalartikel :


Author(s) : Monika Burri, Maja Schniepper (Gruner AG)
Editorial office : WSL, Switzerland
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Beware of caterpillars with urticating hairs

Some species of caterpillars have urticating hairs which can cause extreme itching, skin irritations and damage to eyes and the respiratory system. Therefore care must be taken during work being carried out along the edge of forests, on embankments or whilst tending trees.

Fig. 1 — Oak processionary moth caterpillars.
Photo: Entomology (WSL)
Fig. 2 — Pine processionary moth caterpillars.
Photo: Entomologie (WSL)

Occasionally during the course of maintenance work being carried out along the edge of forests or on street embankments health problems caused by three species of moths can occur. Contact with the stinging hairs of these caterpillars can lead to skin irritation and/or allergic reactions of the skin, mucus membranes or respiratory systems. The species in question are the following:

  • The oak processionary moth (Thaumetopoea processionea)
  • The pine processionary moth (Thaumetopoea pityocampa)
  • The gold tail moth (Euproctis chrysorrhoea)

Why can these caterpillars be dangerous?

Most of us regard butterflies as colourful messengers of summer. Some people are aware that caterpillars can eat voraciously. For instance, the cabbage white dines in the vegetable garden. The mottled umber can damage fruit plantations by eating buds, leaves and blossom. The orchard ermine wraps up the left over bare wood and its surrounding area in white webs. Asian gypsy moth caterpillars manage to defoliate whole forests during their rare mass outbreaks and are a nuisance to people living near by when they move into gardens and houses by the hundreds or even thousands.

All of these species catch our eyes with their webs, nests and intense defoliation, but although they cause a certain amount of damage to cultivated plants they are however harmless from a health point of view.

The three aforementioned species are also noticeable thanks to their nests, webs, defoliation and caterpillar processions but they can also cause health problems. These caterpillars have stinging hairs which can cause itching, skin irritation and also eye problems or damage to the respiratory system.

What are urticating hairs and what is their function?

Fig. 3 — Infestation of pine processionary moth caterpillars.
Photo: Entomology (WSL)
Fig. 4 — Gold tail moth caterpillar.
Photo: Beat Fecker (WSL)

Urticating hairs protect the caterpillars and their later stages of development (Pupae, moth, egg) from predators.

  • They are tiny: 0.1 – 0.2 mm (This is only true of the processionary moth –the gold tail moth has easily visible golden brown hairs.)
  • They are abundant: 600,000 per caterpillar.
  • They stick: in the nest, on the bark, in the grass, in foliage and on clothes.
  • They snap off when the caterpillar feels threatened and keep their potency over many years.

How does one come into contact with the hairs?

  • By being near to or in the general surroundings of infested bushes or trees. The hairs drift in the air and can be blown over a distance of 200 m.
  • If the nests or caterpillars are touched.
  • If work is being carried out and caterpillar hairs which are present on the ground are stirred up: e.g. by raking up leaves, mowing, or clearing up trimmings.
  • When bark in which there was once a processionary moth nest is touched or worked. (The nest of the oak processionary moth is mainly to be found on the trunk, whilst the nests of the pine processionary moth and the gold tail moths are in the periphery areas of the crown.)

The urticating hairs of the golden tail moth, although less aggressive, are however used for protection in every stage of development: the hairs which are produced only by the caterpillars are woven into the pupae cocoons the female then strokes them onto her abdomen from where they make their way into the egg clutches during egg laying.

Symptoms and precautions

Skin irritations (caterpillar dermatitis)

One reaction after contact with stinging hairs of the gold tail moth may be extreme itching; this can occur hours after contact, but may continue over several days. Although only a slight rash occurs after contact with the gold tail caterpillar extreme itching can prevent a person sleeping. After contact with the stinging hairs of oak processionary or pine processionary moths the following symptoms may also occur:

  • Redness, swelling, inflammation of the skin
  • Inflammation of the conjunctiva and eyes
  • Redness, aversion to light, swelling of the eyelids, inflammation of the inside of the eye (extreme case)
  • Inflammation of the upper respiratory system
  • Inflammation of the throat, swelling of the mucus membrane in the nose, bronchitis, asthma like symptoms, allergic shock reaction (extreme case)

In the case of processionary moths a further complication is that increased caterpillar contact increases the sensitivity and therefore the intensity of reaction of the affected person.

Fig. 5 — Possible results of contact with the stinging hairs of processionary moths.

Immediate measures to be taken when affected

  • Shower immediately, wash hair (rinse with soap, do not rub), change clothes.
  • Do not scratch; free possible contaminated areas of skin using adhesive tape.
  • Contaminated clothes should be stored in an air tight container and washed separately at 60 °C, or even hotter.
  • The affected areas can be treated with antihistamine (E.g. Fenistil).
  • Should there be extreme itching or if other conspicuous symptoms should appear a doctor should be consulted and he should be informed that the person has been in contact with caterpillar hairs.

In Switzerland health problems caused by caterpillars are treated by health insurance companies as accidents (analogue with tick bites).

Measures to be taken in infested areas

a) Assessment of the situation

  • What species is involved? Does it have urticating hairs?
  • Conflict potential in the area: how often and how urgently must the area be entered?

After a situation has been assessed and it is clear that there is an infestation of caterpillars with urticating hairs then a plan of action will be prepared using the following guide lines:

  • Work should be finished with protective clothing or put on hold
  • The area should be cordoned off and information made available for probable users
  • The case should be recorded and documented (map, photos) for the cantonal security representative and as a basis for long term measures
  • Control measures for caterpillars or plans for long term preventative measures should be planned together with experts.

b) Prevention measures

In areas infested by gold tail or pine processionary moths the total removal of all possible winter nests can provide infestation free areas which should last at least up until the following autumn.

Non dangerous species without urticating hairs

Fig. 6 — Small eggar.
Photo: Beat Wermelinger (WSL)
Fig. 7 — Ermine moth.
Photo: Beat Wermelinger (WSL)

Harmless species which have a similar biology and whose population could be endangered should not be controlled:

a) Small eggar

Wide spread in the canton of Wallis, otherwise sporadic in the cantons of Tessin, Bündner Rhine Valley, the area around Zürich, and in the Walensee area. Due to its rarity it should be protected. Nests should never be removed!

  • Feeding plants: Birch, blackthorn, sweet chestnut, sweet cherry
  • Difference to gold tail moth: the up to 20 cm large nest hangs like a bag
  • Difference to the pine processionary moth: the species does not go onto pine trees

b) Ermine moths

Nine very similar species, generally very widespread.

  • Feeding plants: spindle tree, fruit trees, willow and other bushes
  • Similarities: complete defoliation of bushes (in June)
  • Differences: after defoliation veil like webs cover whole plants.

Distribution and occurrence

The three species with urticating hairs were at one time more widely spread in Switzerland and more common. Their population was drastically reduced by the thoughtless use of insecticides in agriculture. In Switzerland and in near by neighbouring countries they are now once again on the increase. This increase is being encouraged by global warming. Distribution maps can be found in the leaflets (see download).

The pine processionary moth has been observed for some time in several areas in southern Switzerland. Since the beginning of the 1990’s there has been an increase in the appearance of the oak processionary moth and the dark gold tail moth: with the oak processionary moth occurring more rarely than the dark gold tail moth. All three species are capable of mass reproduction.


  • leaflet: caterpillars with urticating hairs in German (PDF)
  • leaflet: oak processionary moth in German (PDF)
  • leaflet: pine processionary moth in German (PDF)
  • leaflet: gold tail moth in German (PDF)

More on waldwissen.net

Original article: Burri, M., Schniepper, M. (2006): Schmetterlingsraupen mit Brennhaaren. Merkblatt zu Arbeitssicherheit und Gesundheitsschutz in den Strassenunterhaltsdiensten. Herausgegeben von der Koordinationsgruppe Arbeitssicherheit im Strassenunterhalt (KGr AS SUD). www.nationalstrassen.ch
Online version : 16.09.2009

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