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Pseudococcus longispinus

Longtailed mealybug. Photo: David Cappaert, Bugwood.
Scientific Name: 
Pseudococcus longispinus
Common Name: 
Longtailed Mealybug
Growing Degree Days (GDD's): 
None available at this time.
Host Plant(s) Common Name (Scientific Name): 
Apple (Malus spp.)
Deodar cedar (Cedrus deodara)
English ivy (Hedera helix)
Firethorn (Pyracantha spp.)
Holly (Ilex spp.)
Oleander (Nerium oleander)
Rhododendron (Rhododendron spp.)
Stone pine (Pinus pinea)
Yew (Taxus spp.)
Insect Description: 

While the longtailed mealybug is typically a pest of greenhouses and conservatories, or outdoors in warmer parts of its range, it is occasionally found on trees and shrubs in warmer, "protected" urban locations. The longtailed mealybug, like other mealybugs, is covered in white, waxy, mealy secretions over their bodies. Long filaments form a ring around the insect. The distinct difference for this species being that the filaments of wax on the posterior end of the body of the adult females are very long - and may be as long as the insect's entire body. Note that these long "tails" break off easily, however when observing a group of individuals, at least a couple are likely to have retained them. Adult female longtailed mealybugs are approximately 3 mm in length and white in color. This insect reproduces rapidly, and all life stages often occur on the same host plant at the same time. In the warmer portions of their range, the females never lay visible eggs, but rather the nymphs hatch immediately upon egg laying and are referred to as crawlers. First and second instar crawlers have been determined to be able to disperse using the wind (Barrass et al., 1994). Crawlers are covered in much shorter waxy filaments. Female mealybug nymphs undergo 3 instars, and males undergo 4. Adult male mealybugs are winged. Longtailed mealybugs excrete honeydew, a sugary liquid waste that is often attractive to ants - which may carry mealybugs to new locations while farming the honeydew. There may be two to three generations per year, depending upon local temperatures. In warm, urban locations, immatures may be able to overwinter on the bark of their host plants.

Damage to Host: 

The longtailed mealybug is a generalist feeder with a large host list. Mealybugs infest all plant parts - the feeder roots, root crowns, stems, twigs, leaves, flowers, and fruits of their host plants. The damage that occurs due to longtailed mealybug feeding is because of the loss of host plant sap - which leads to discolored and wilted foliage (terminal leaves may turn yellow), sometimes deformed leaves, and possibly the death of infested plant parts if populations are high enough. In landscapes, dieback may be uncommon. Moderate to heavy populations can create ample amounts of honeydew, which is then colonized by sooty mold. Sometimes, mealybugs are found on the same host plant mixed with populations of scale insects or whiteflies. In grapevines, longtailed mealybugs may be able to transmit certain viruses that impact the plant.


Researchers in Australia were able to catch first and second instar longtailed mealybug crawlers on sticky traps. The number of individuals caught was positively correlated to wind speed and daily maximum temperature. Visual scouting for mealybug life stages, honeydew, or sooty mold can be focussed on densely growing host plants growing in sheltered locations. Flip leaves over and look at host plant foliage undersides or stem undersides for individuals, particularly in areas coated with honeydew and sooty mold. Looking for the presence of ant activity may also help locate a population of longtailed mealybugs. 

Cultural Management: 

Discouraging the activity of ants in these locations may be necessary to help reduce mealybug spread. Do not use dense plantings of host plants, particularly in warm, urban settings. 

Natural Enemies & Biological Control: 

An insect-killing fungus has been reported killing longtailed mealybugs in populations in Florida. The fungus, Entomophthora fumosa, is capable of infecting mealybugs and other plant pests.

In parts of its range, certain parasitoid wasps have been shown to impact the population of the longtailed mealybug. These include but are not limited to: Anarhopus sydneyensis, Hungariella peregrina, Pseudaphycus angelicus, Tetracnemoidea syndneyensis, and Coccophagus gurneyi.

Additionally, generalist, predatory beneficial insects such as lady beetles and lacewings may also feed on mealybugs, but may not reduce their populations below pest levels.

Chemical Management: 

Acephate (NL)

Azadirachtin (NL)

Beauveria bassiana (NL)

Bifenthrin (NL)

Buprofezin (NL)

Carbaryl (L)

Chlorpyrifos (N)

Chromobacterium subtsugae (NL)

Clothianidin (NL)

Cyfluthrin (NL)

Dinotefuran (NL)

Fenpropathrin (NL)

Flonicamid+cyclaniliprole (N)

Tau-fluvalinate (NL)

Gamma-cyhalothrin (L)

Horticultural oil (L)

Imidacloprid (L)

Insecticidal soap (NL)

Isaria (paecilomyces) fumosoroseus (NL)

Lambda-cyhalothrin (L)

Malathion (L)

Neem oil (NL)

Permethrin (L)

Pyrethrin+sulfur (NL)

Pyriproxifen (eggs, nymphs) (L)

Spinetoram+sulfoxaflor (N) 


First instar crawlers may be more susceptible to chemical management options, as they lack the protective waxy coating of older individuals.

When used in nursery settings, chlorpyrifos is for quarantine use only.

Active ingredients that may be applied systemically include: acephate (injection), acetamiprid (injection), azadirachtin (injection), clothianidin (soil drench), dinotefuran (soil drench), imidacloprid (soil drench), and neem oil (soil drench).

Make insecticide applications after bloom to protect pollinators. Applications at times of the day and temperatures when pollinators are less likely to be active can also reduce the risk of impacting their populations.

Note: Beginning July 1, 2022, neonicotinoid insecticides are classified as state restricted use for use on tree and shrub insect pests in Massachusetts. For more information, visit the MA Department of Agricultural Resources Pesticide Program.

Read and follow all label instructions for safety and proper use. If this guide contradicts language on the label, follow the most up-to-date instructions on the product label. Always confirm that the site you wish to treat and the pest you wish to manage are on the label before using any pesticide. Read the full disclaimer. Active ingredients labeled "L" indicate some products containing the active ingredient are labeled for landscape uses on trees or shrubs. Active ingredients labeled "N" indicate some products containing the active ingredient are labeled for use in nurseries. Always confirm allowable uses on product labels. This active ingredient list is based on what was registered for use in Massachusetts at the time of publication. This information changes rapidly and may not be up to date. If you are viewing this information from another state, check with your local Extension Service and State Pesticide Program for local uses and regulations. Active ingredient lists were last updated: January 2024. To check current product registrations in Massachusetts, please visit: .