Azalea Bark Scale Pictures:
The picture above shows the adult female azalea bark scale. She looks like a small tree with red flowers. Her body is covered with tiny white hairs which are very hard to see from this distance.
These hairs look like little white snowflakes floating in the air. They are called azaleas because they resemble the petals of an old-fashioned azalea bush or azule (Azulena grandiflora).
Picture 1: Adult Female Azalea Bark Scale
Adult females usually have one to two million hairs. They grow up to three inches long and weigh between 2 and 3 grams each. The female azalea bark scale has four pairs of legs, but only three pairs of legs are used during reproduction.
The other pair is used for support while the eggs develop inside her body. The eggs are laid in clusters on the underside of leaves. After several days, the eggs hatch into larvae that feed on the plant tissue. The larvae then move down through the leaf veins until they reach their destination – your skin!
Picture 2: Azalea Bark Scale Eggs Inside Leaf Vein
The picture below shows a larva from another species of azalea bark scale. The female Azalea bark scale lays her eggs in clusters on leaves. It takes about four weeks for the eggs to hatch.
Then it takes another month until the eggs turn into scales. The female adult feeds on the nutrients from the leaves. This causes yellow spots to form on the leaves. As the infestation increases, the plant becomes covered in yellow spots and falls over from lack of nutrients. As soon as you see one adult or egg, there are probably thousands more that you cannot see!
Picture 3: Azalea Bark Scale Larvae Inside A Leaf
Azalea bark scale lives inside the leaf and causes tiny yellow spots on the leaves. The adult female is light brown and has white hairs that cover her body. You can barely see the adult female because she is so well camouflaged against the leaf.
You can barely see the eggs which look like yellow grains of wheat in picture 2. The eggs are hard to see because they have a waxy coating that repels water.
Picture 4: Yellow Spots On Leaf
This picture shows the adult male and female in the early stages of mating. Both adults have wings, but only the female leaves the tree to look for a male. When she finds one, she sends out a perfume that signals that she is ready to mate.
The male flies down from his position on the leaf to mate with her. After mating, the female flies back up to the leaf to lay her eggs. The male dies after mating. The female lives for about one month and lays about 300 eggs during that time.
The eggs are laid in clusters of 30-40 under the upper and lower sides of the leaves. The clusters are about the size of the head of a pin. They start out white but soon turn yellowish-brown.
They usually hatch in about 4 weeks and then take about a month to turn into an adult scale. The time from egg to adult depends on the temperature.
The whole life cycle takes about 6 months which is much longer than most insects. This slow development from egg to adult is called “instar” or “instars.” Scale insects go through several instars before they mature and turn into an adult.
Each stage looks different than the previous one.
The male and female scales look different even though they only live for a month. The female has more white hairs around her wing bases than the male. Her body is wider at the base than the male’s body.
This is where she stores her eggs. The male is slimmer and his wings extend out past his legs. The picture below shows an adult female on the left and an adult male on the right.
Picture 5: Adult Male And Female Scale
The male is very light green, almost white. The female is darker green and sometimes has a pinkish look to her body. There is a white waxy substance around the base of her wings called “pruinose.” The female also has little white hairs that cover her body.
She does not have as many of these hairs as other scale insects.
The eggs are very small. They look like tiny grains of yellow wheat. Just before they hatch, they look like little white rice kernels.
Each egg is about 1/50 inch in length. Each female lays about 300 eggs during her life span of one month. After the eggs hatch, they look like tiny white grains. They turn brown before they turn into an adult scale insect. It takes about 4 weeks for them to turn into an adult scale insect. The whole life cycle takes about 6 months.
Did You Know?
The bodies of both male and female scale insects are hollow. Air passes through holes in their bodies. They use this air to make their wings move. Wings are not used for flying. They are used to make the insect look bigger so that enemies will not attack it. The wings can also make a buzzing sound that frightens away enemies and catches the attention of friends.
Scale insects are related to mealybugs and aphids. They all have a soft body, no wings and many legs. The scale insect is related to the mealybug in that they both have scales that protect their bodies.
They are related to aphids because they both suck fluids from plants.
Both adult and young mealybugs and aphids can be controlled by putting a drop of detergent in a gallon of water and spraying the mixture on the tree or bush. They will also die when sprayed with the insecticide “Orthene”. The same is true for scale insects.
The adults and the young can also be controlled with a special microscopic insect called “fungus.” You can buy this at most garden supply stores. It is mixed with water and then sprayed on the trees or bushes.
The fungus gets into the insects’ bodies and kills them. This too will kill the young mealybugs and aphids as well as the adult ones. It will take about a month before you start to see dead insects. These methods are the most effective way to control these insects.
You can also use a “wasp parasite” to kill your scale and mealybugs and aphids. This is not a true wasp. It just looks like one.
The females look like tiny yellow wasps. They have an extremely short life span and do no harm to plants or people. The male larva are white and look like little white worms. They are not harmful and do not attack the insects. They live in the bodies of scale insects and mealybugs. When they are full grown, they come out of the dead insects and turn into tiny yellow winged males.
The males will not harm your plants or you. The females will look for a mate and then find scale insects or mealybugs to lay their eggs inside of. When the eggs hatch, the young eat the “meat” of the dead insect.
This kills the insect and stops it from feeding on the plant.
If you have a lot of insects to control, the wasp parasite may not be effective. It would take quite a few of them to kill a large number of insects. The wasps are only effective when used by themselves.
You can use them in combination with the fungus or the detergent and water solution to get good results.
The adult scale insects do not move very much. They stay in the same spot unless the leaf they are on is shaken. After the adult insects die, their bodies remain attached to the leaf.
These dead shells can look like bumps on the leaf if there are not too many of them.
The young mealybugs and aphids move around quite a bit. They can be found on almost all parts of a plant. The adult female mealybugs and aphids do not move at all.
You may find one on a leaf and when you go back to look at it again, you’ll find two or more females there.
The eggs of the mealybug and aphid are usually found on the feet of the females. They are white, oval shaped and attached to the legs of the female. The eggs of the scale insect are found under the hard shell.
They are smaller than the seeds of a strawberry.
INSECTS THAT LOOK LIKE MOSAIC VIRUS
Mosaic virus looks a lot like some insects. The difference is that mosaic virus will not move around like the insects do and it will not get bigger after you have seen it for a while.
There are two insects that look like mosaic virus that you should be aware of – the mite and thrips. The mite is too small to see without a strong magnifying glass. It is round and reddish brown.
You will need to use a hand lens to see it well. If you are not sure if you have mites, but you do have small round reddish brown bugs, they are probably thrips. Thrips are almost invisible to the naked eye. You will need to use a strong magnifying glass to see them well.
Mites are rarely a problem on indoor plants. They can be a serious problem if you have a lot of plants outdoors and you don’t take the proper steps to keep them out.
The mite usually attacks weak or young plants. It sucks the juices from the stems or leaves. You will see the damage long before you see the mites themselves.
The leaves first turn yellow and wilt. They later turn brown and die. You will see fine webbing around the bottom of the leaves and stems. This is the mites’ egg sacs. The eggs will not be visible without a strong magnifying glass.
You can pick off the mites with your fingernails or a toothbrush if you have a lot of plants. To control mites, use the insect fogging technique described in this chapter. You can also treat with pyrethrin.
Use a concentration of about 1%. Make sure you cover the bottoms of the leaves as well as the tops.
The thrips are active creatures. They move quickly and are difficult to control. Thrips also have an armored outer shell that protects them from sprays.
These little bugs attack plants in much the same way that the mites do. They suck the juices from the stems and leaves. You will see fine webbing around the bottom of the leaves and the thrips themselves. They are very small, about 1/5 of an inch in length. They are darker than the color of the leaves they are attacking and have a characteristic narrow body shape.
There is not much you can do to control thrips once they have infested your plants. Picking them off by hand can be tedious and very time consuming. In addition, they move so quickly that you can’t get them all.
The best thing to do is to prevent their entry in the first place.
The best prevention for all these insects is good gardening practices. That means keeping your growing area clean. Clean up all the old leaves and other debris from around your plants.
If you do this once a week, you will keep down the numbers of pests that feed and breed in this “junk food”.
Flush out your pots once a month with a strong spray of water. Thrips like to hide in the furrows of the pot and will not be harmed by the water. The flush will take care of the insects that could not get out of the way of the water.
Once you have discovered that you do, in fact, have one of these pests, do not ignore it. These insects can kill your plants very quickly if you do not treat them immediately.
Sources & references used in this article:
Discovery and spread of Eriococcus lagerstroemiae Kuwana (Hemiptera: Eriococcidae), a new invasive pest of crape myrtle, Lagerstroemia spp by ME Merchant, M Gu, J Robbins, E Vafaie… – … . org/resource/pdf …, 2014 – researchgate.net
Matters of Scale: Wax and Azalea Bark Scales by D Gilrein – 2015 – ecommons.cornell.edu
Crape myrtle bark scale: A new exotic pest by M Gu, M Merchant, J Robbins, J Hopkins – EHT-049, 2014 – cdn-ext.agnet.tamu.edu
Insect pests of azaleas and camellias and their control by LL English, GF Turnipseed – 1940 – aurora.auburn.edu
[IN1218] Featured Creatures: Crapemyrtle bark scale by M Borden, X Martini, A Dale – EDIS, 2018 – journals.flvc.org
JARS v62n2-Mealybugs: A Threat to Azaleas by E Gural – scholar.lib.vt.edu
Crape Myrtle Bark Scale on Crape Myrtle Tree by E Pugh, FM Gardener – fairfaxgardening.org
Control of Insect Pests Ornamentals by JC Schread – Journal of Economic Entomology, 1954 – academic.oup.com
Evidence for resistance of deciduous azaleas to azalea lace bug by SK Braman, AF Pendley – Journal of Environmental …, 1992 – meridian.allenpress.com