Longtailed mealybug

Pseudococcus longispinus

Being present in many Australian grape growing regions, longtailed mealybugs are generally not a major issue, but in certain circumstances can become a significant problem for vignerons. Like scale pests, mealybug feed on the plant’s sap, excreting honeydew as a waste product. The honeydew provides a food source for ants, but also a medium for sooty mould to grow on. This sooty mould can be a contaminant in the wine production process or affect the appearance of table grapes, leading to the downgrading of fruit. Mealybugs, including longtailed mealybugs, are also found in other crops including citrus, apples, pears, peaches, nectarines, plums and apricots, where contamination and appearance issues from sooty mould can impact fruit quality.

Refer to the links below on different mealybug species.

Description

Adult female longtailed mealybugs are distinguished from other mealybug species by their long anal filaments which are fine and often longer than the length of their body. Mealybugs are approximately 3-4 mm long and are covered in a white mealy wax, which acts as a protective layer. If squashed, their body contents are a yellow colour.

Rather than producing eggs like other mealybugs, longtailed mealybugs produce live young that are less than 1 mm long. These groups of crawlers remain under their mother’s body before they disperse, seeking feeding sites such as the underside of leaves, a grape bunch or the stem end of stone fruits such as plums as well as the calyx end of pome fruit.

Control

Mealybugs can be controlled by encouraging predators such as ladybird beetles, predatory beetles, lacewing larvae and parasitoid wasps and by the considered use of insecticides targeted at the juvenile life stages. However, focusing control on chemicals can be problematic for a number of reasons as their waxy coating repels sprays and spray contact can be difficult. It is therefore important to strategically apply an insecticide based on its attributes.

Movento being a systemic product should be targeted at the juvenile stage of the insect allowing the insect to ingest the product through feeding on the plant parts. Movento® is soft on many beneficial insects, including parasitic wasps, pirate bugs, hoverflies and lacewings. It is registered for the control of longtailed mealybug in grapes, pome and stone fruit and should be applied at the onset of crawler emergence.

Confidor® is registered for the control of longtailed mealybug in ornamental plants.

Related Pests

Mealybug

Pseudococcus virburni (Tuber mealybug), Pseudococcus longispinus (Longtailed mealybug), Planococcus citri (Citrus mealybug), Phenacoccus solenopsis (Cotton/Solenopsis mealybug), Maconellicoccus hirsutus (Pink, grape or hibiscus mealybug)

While there are native mealybugs, the above are considered sap sucking pests on a range of hosts including grapes, citrus, cotton, peanuts, mangoes, passionfruit, apples, pears and stone fruit.

Like aphids, mealy bugs can cause distorted leaves and weakened plants that are covered with shiny honeydew and often, sooty mould.

While mealy bugs can cause significant loss through sap sucking, the most significant damage relates to the secretion of honey dew which encourages the growth of sooty mould and other fungi. It is also visually undesirable, makes the fruit sticky and in some fruits, prevents the drying of fruit for dried fruit production. In grapes, mealybugs are also vectors for diseases such as leaf roll virus.

Refer to the links below for more detailed information on different mealybug species.

Citrus mealybug

Planococcus citri

Citrus mealybugs are the most common and widespread of the mealybug species and as their name suggests, their main host is citrus, while other hosts include mangoes and passionfruit. Although significant economic damage is rare, they still have the potential to damage fruit.

Refer to the links below on different mealybug species.

Tuber Mealybug

Pseudococcus viburni

Tuber mealybugs, also known as obscure mealybugs, are often confused with the more prevalent longtailed mealybugs. Tuber mealybugs are a pest in some grape growing regions of eastern Australia and parts of south west Western Australia. Found in all States and Territories, they are a significant pest of pome and stone fruit orchards and inland citrus crops.

Refer to the links below on different mealybug species.

References

Department of Primary Industries (2005), ‘Long tailed mealy bug’, https://www.dpi.nsw.gov.au/agriculture/horticulture/citrus/content/insects-diseases-disorders-and-biosecurity/inect-pest-factsheets/long-tailed-mealy-bug

DPIRD (2018), ‘Mealybugs in grapevines and deciduous fruit tree crops’, https://www.agric.wa.gov.au/minor-fruits/mealybugs-grapevines-and-deciduous-fruit-tree-crops

SARDI (2016), ‘Fact Sheet: Identifying Mealybugs on Inland Australian Citrus’, https://www.pir.sa.gov.au/__data/assets/pdf_file/0007/285532/Identifying_Mealybugs_on_Inland_Australian_Citrus_Fact_Sheet.pdf

Wine Australia (2019), ‘Mealybugs’, https://www.wineaustralia.com/growing-making/pest-and-disease-management/mealybug-management