- 1 Mealybugs Overview
- 2 Types Of Mealybugs
- 3 Life Cycle Of Mealybugs
- 4 How To Get Rid Of Mealybugs
- 5 Frequently Asked Questions
Only a tenth to a quarter of an inch long, tiny mealybugs don’t look particularly dangerous. However, these voracious plant-suckers can literally suck the life out of your plants if you’re not careful.
Today, I plan on helping you to stop the mealybug manifestation on your plants forever. Once you’ve read the information below, you should know everything you need to get rid of these little pests and keep them out!
Good Products To Eliminate Mealy Bugs:
Beneficial Insects That Can Help:
Listen to this post on the Epic Gardening Podcast
|Common Name(s)||Mealybugs, longtailed mealybug, long-tailed mealybug, citrus mealybug, Gill mealybug, Gill’s mealybug, Comstock mealybug, grape mealybug, solenopsis mealybug, obscure mealybug, tuber mealybug, pink hibiscus mealybug, coconut mealybug, pineapple mealybug, and a number of other names|
|Scientific Name(s)||Pseudococcus longispinus, Ferrisia gilli, Pseudococcus comstocki, Planococcus citri, Pseudococcus maritimus, Phenacoccus solenopsis, Pseudococcus viberni, Pseudococcus affinis, Maconellicoccus hirsutus, Nipaecoccus nipae, Dysmicoccus brevipes, Pseudococcus brevipes, Dactylopius brevipes and many more|
|Plants Affected||A very wide majority of food and ornamental plants and trees. Typically does not impact grasses.|
|Common Remedies||Rubbing alcohol, insecticidal soap, mycoinsecticides, neem oil, and a variety of beneficial insects including ladybugs, lacewings, and the mealybug destroyer.|
Types Of Mealybugs
Falling under the larger category of scale insects, mealybugs are part of the family Pseudococcidae. These unarmored scale insects lack the semi-rigid or rigid shell that many other scale insects have. Instead, the mealybug secretes a wax-like coating for defense.
There are over 2200 species of mealybugs, but only a portion of them are considered common garden pests. Here’s a short list of some of the most common garden offenders.
Pseudococcus longispinus, ‘Longtailed Mealybug’, ‘Long-Tailed Mealybug’
A common greenhouse pest or nursery pest. The name originates from the pair of long tail filaments which extend from its rear, and often are longer than its body.
Ferrisia gilli, ‘Gill Mealybugs’, ‘Gill’s Mealybug’
Stone fruits such as apricot or peach are at risk from gill mealybugs, as are some nuts like pistachio or almond. Grapes and deciduous ornamentals may also be at risk.
These pinkish mealy bugs are usually covered in white wax, and may also have a covering of long, crystalline filaments.
Pseudococcus comstocki, ‘Comstock mealybug’
The Comstock mealybug is common in the San Joaquin Valley area of California, and primarily goes after lemon trees. Similar in many ways to the citrus mealybug, it has a pair of medium-length spines protruding from its rear.
Planococcus citri, ‘Citrus Mealybug’
Citrus mealybugs don’t have the same long tail that Pseudococcus longispinus has, but they do impact some similar plants. Indoor ornamentals may be at risk from the citrus mealybug. They of course also go after citrus, as their name would imply.
The citrus mealy bugs have short filaments of equal length distributed around their bodies, and can occasionally have a dark stripe running down the back.
Pseudococcus maritimus, ‘Grape mealybug’
Grape mealybugs tend to favor grapevines. Visually similar to the obscure mealybug (mentioned below), it is best identified by the color of its defensive excretions, which are a reddish-orange in hue.
These are often confused with the obscure mealybug, and are best identified by the excretions and their preferred foodstuff.
The grape mealybug is from and resides mostly in central and northern California.
Phenacoccus solenopsis, ‘Solenopsis mealybug’
This highly common mealybug is found on a wide variety of crops. Among those are many different food crops like tomatoes, potatoes, melons, and eggplant. These mealybugs have a long, oval-shaped body which is dark in coloration, but covered in a white waxy secretion.
Pseudococcus viberni, ‘Pseudococcus affinis’, ‘Obscure mealybug’, ‘Tuber mealybug’
Closely related to the grape mealybug, the obscure mealybug does not originate in California. However, it can be found there now, as well as South America, Australia, New Zealand, and Iran among others.
This long, oval-bodied mealybug has small filament protrusions from its sides. Its white to greyish-white body is usually coated in a thick layer of white or off-white wax. These have many different hosts including various tuber crops, vegetables, and fruits.
Maconellicoccus hirsutus, ‘Pink hibiscus mealybug’
The pink hibiscus mealybug doesn’t limit itself to just hibiscus plants. They’re also quite fond of fig and citrus trees, grapes, and a number of other ornamentals.
These tiny pink insects are coated with a white waxy secretion, sometimes quite heavily. The nymphs look almost like a mealy wax patch in their young form.
Dysmicoccus brevipes, ‘Pseudococcus brevipes’, ‘Dactylopius brevipes’, ‘Pineapple mealybug’
One of the lesser-known mealybugs in most of the United States, the pineapple mealybug is a pink or pinkish-orange color. It goes after pineapples, citrus, coffee, cotton, and many Ananas-species trees (including bananas).
This pest is mostly found in pineapple-growing regions of the world, including all of the Hawaiian islands.
It can be found on the leaves, fruit, or base of the host plants. Pineapple mealybugs are the root cause of many pineapple crop failures, as they cause pineapple wilt (also referred to as mealybug wilt or edge wilt) and mealybug stripe.
Nipaecoccus nipae, ‘Coconut mealybug’
Yellowish-orange in coloration, the coconut mealybug is found on a wide variety of palm trees, avocados, and some flowering tropical plants. These are unusual in that the wax they produce is a bright yellow color.
When excreted, the wax forms a series of triangular, pyramid-like spikes that protrude from their bodies. Adults are larger with more pronounced pyramid spikes and appear to be more yellow due to their thicker wax coating.
Nymphs tend to have less wax buildup and thus look more goldenrod or orange.
Life Cycle Of Mealybugs
With the exception of the longtailed mealybug, the mealy bug life cycle consists of an egg stage, a nymphal stage sometimes referred to as the “crawlers” stage, and the adult mealybug.
For longtailed mealy bugs, the life cycle is only the crawler stage and adult, as female longtailed mealy bugs give birth to live young.
Adult mealybugs will lay their eggs inside of a cotton-like pouch which protects them from the elements. This cottony mass is often mistaken for downy mildew.
Once the adult female has laid all of her eggs, she will die off. However, the average adult female can lay 300-600 eggs, making population growth startlingly fast.
The eggs will hatch within 5-10 days in good weather conditions. Inclement weather may cause the hatching to be delayed so that the egg sac can protect the young insects.
Hatched nymphs, or “crawlers”, have vestigal legs and will move around. This is the period of time when mealybugs travel and spread to other plants.
In farm situations where multiple plants of the same species are close together, it’s common to see initial damage on the outer plants of a field. As infestation spreads, the pests work their way inward.
This crawler phase will last for 6-9 weeks, during which time they mature. They will then briefly pupate and emerge as an adult.
Females tend to remain stationary on their host plant (although they can still move, unlike other scale insects). Males do not feed after pupation, and so they will live for only a couple days, mating with any females they might find before expiring.
The cycle continues as the next series of adult mealybug females lays their eggs (or live young, for longtailed mealy bugs), and then die off. There can be multiple generations of mealy bugs in a given year.
Common Habitats For Mealybugs
These pests tend to live in and around what they eat. Different types will prefer leaves, stems, the plant’s base, the roots, and even the fruit in some cases as a home.
Some forms of scale insects build up at the joint of leaf and stem, where they can have some shelter from the elements. Others merely secrete extra protective wax and live openly on cactus pads or leaves where they are more exposed.
It really depends on the particular species and plant as to where they’re most likely to be found, but it’s quite likely that a buildup of waxy secretion will be visible, especially if eggs are present. Cottony, glassy filaments of wax and cotton-like egg pouches may also be noticed on the plant.
What Do Mealybugs Eat?
Depending on the species of mealybug, you will find them on an ever-increasing number of food crops, tropical plants, and other ornamentals.
Most of the mealybugs that I focused on above are those which are common on fruit or nut trees or on food crops. However, there are variations of mealybugs that prefer ornamentals or other trees.
For instance, the cypress tree has a mealybug that will hide in the crevices and just underneath its patchy bark. There is a form of mealybug which forms on cacti as well.
All mealybugs consume the saps or juices of the plant on which they attach themselves. They do not typically chew up leaves, but a large infestation can cause visible signs of yellowing.
Withered leaves and falling leaves are not uncommon. Fruit may drop prematurely, and stunted plants may not be able to produce new leaves. A large enough infestation will cause plant death.
Mealybugs And Ants
There’s a relationship between mealybugs and ants. These pests are regularly farmed by ants who provide them shelter and protection and keep them clean. In return, the ants get to consume honeydew, a sweet secretion of the mealybugs.
While not all mealybugs are cared for in this fashion, many species can be. Some of the most commonly-farmed mealy bugs include the pineapple mealybug, citrus mealybug, and the pink hibiscus mealybug.
How To Get Rid Of Mealybugs
Mealybugs are attracted to plants with high nitrogen levels, and unfortunately, that tends to include most of our prized garden plants. So what can you do to get rid of them? Here’s a list of some of the best ways to eliminate them.
Organic Mealybug Control
Light, early infestations can be taken out with a cotton swab and some rubbing alcohol. Simply dip the tip of the swab into the alcohol and dot the pests. They will die out.
On succulents, you may find it easier to use a light mist of pure rubbing alcohol in a sprayer, but be careful with how much you use. Too much can harm the leaves.
Using a good insecticidal soap can eliminate mealybugs and clear away egg debris. The soap cuts through the outer waxy secretions and will damage the insect’s skin, causing dehydration and death. I recommend Safer Soap, which works on a wide number of sucking pests.
A mycoinsecticide can handle the larger-scale infestations, too. Products such as Botanigard ES have a low-risk biological fungus in it. The fungal spores work their way inside the pest insects and kill them, and the plants are not harmed. This organic method of mealybug control works surprisingly well.
Environmental Mealybug Control
Avoid overwatering and excess fertilizing. Plants that are too nutrient-dense tend to be high targets, as are ones which are saturated with lots of plant juices.
Blast mealybugs and other scale insects off your plants with a hard spray of water. While crawlers may be able to go back up the plants, the adults will not. They will die out in a couple of days from starvation.
Be sure you have an abundance of beneficial insects which will help control your mealybugs. Ladybugs will eat the eggs and the nymph forms of the pests. Lacewings also eat the eggs, but will help control both crawlers and the adult scale.
An uncommon, but equally-effective beneficial insect is the mealybug destroyer, Cryptolaemus montrouzieri. These small beetles were originally transported to the US from Australia in the 1890’s to help clear up citrus mealybug infestations. They’re quite useful in greenhouses as well as outdoors and will happily eat all life stages of mealy bug.
To keep mealybugs at bay, spray your plants once a week with a solution of neem oil in water. If you coat all plant surfaces, the neem oil will slow or stop feeding on your plants by a wide variety of pests. In addition, the oil coats any eggs or crawlers and will smother them.
Since mealybugs and ants have a symbiotic relationship, it’s also essential to eliminate ants if you spy any around your mealies. Keeping the ants at bay reduces the chance that they’ll be protected and cared for, which makes it easier to eliminate them entirely. Check out my post on ant control tips for good ways to get rid of them!
Frequently Asked Questions
Q: Are mealy bugs harmful to humans?
A: No, not really. While they do spread some viruses to grape plants and can transmit other plant diseases, they don’t bite humans. However, some people do have a sensitivity to the waxy secretions they produce, and it can cause skin irritation. Wash your hands after you come into contact with them to be sure you don’t have a problem.
With one of these options, you should be able to eradicate the mealybugs on your prized plants and keep them from coming back. Have you battled with mealybugs before? Have tips I haven’t mentioned here? Let me know in the comments!