Introduction to Mealybug
  

Cryptolaemus montrouzieri
Are ladybird beetles that prey on mealybug and other insects such as Cochineal and some soft scales. These beetles are high-density feeders with a voracious appetite for mealybug and are often referred to as the Mealybug Destroyer. Adult beetles are about 4 mm long, oval in shape, black in colour with a light brown head and posterior. Cryptolaemus larvae grow up to 13 mm long and are covered with long, white, waxy filaments. Read More.

Coccidoxenoides perminutus
Are (often referred to as Cocci’s), are small wasps which originate from Hawaii and now occur widely throughout the world. They are extremely effective parasites of Citrus and Vine mealybug, providing control of low and high-density infestations. C. perminutus are black in colour with noticeable translucent wings, have relatively long antennae and are approximately 3mm long. They can be seen with the naked eye. Females lay their eggs into the first 3 instars of Citrus mealybug and are able to lay between 60 to 90 eggs each. The eggs develop into pupae within the mealybug insect slowly feeding off the host. Read More.

 

 

Du Roi IPM / Lestsitele / South Africa
Tel: +27 (0) 15345 1572
contact@duroibugs.co.za

Mealybug is a pest, which can have a considerable negative economic impact on a wide range of crops and ornamentals. The most important species occurring in citrus are Citrus mealybug (Planococcus citri), Oleander mealybug (Paracoccus burnerae) and Long-tailed mealybug (Pseudococus longispinus) while the most important species occurring on grapevines is the Vine mealybug (Planococcus ficus).

Life Cycle
1. In summer, the full life cycle takes between 30 to 45 days to complete and is temperature dependent.
2. Females can lay up to 550 eggs during their lifetime. These eggs hatch within 6 to 10 days releasing active, mobile crawlers.
3. After the crawler period females experience 2 further stages before adulthood is reached.
4. The males, which have wings and can fly, hatch and are present when females are ready for impregnation.
5. The lifespan of adult males is about 3 to 5 days.

Economic Damage
1. A high population of mealybug can lead to: fruit drop, fruit deformation (‘high shoulders’) and development of discoloured welts on the rind of the fruit.
2. Mealybug secrete copious quantities of honeydew which is a substrate for the fungus, sooty mould. Sooty mould is black in colour and may stain the fruit decreasing packout %’s as well as causing a delay in fruit colour development. Photosynthetic potential, especially of young trees, may be negatively affected if sooty mould infection is severe.
3. Mealybug is a phytosanitary pest in some export markets (USA, Japan) and if found on fruit destined for these markets can result in rejection of the consignment and could place these important markets at risk for the future.

Seasonal History
Mealybug over-winter in the soil on roots or on the plant. They hide in crevices on the bark, under loose bark and other protected areas such as curled leaves. Populations begin to increase from September, peak in late December early January, and begin to decline towards the end of March/April, depending on temperature and parasitism. Due to mealybug’s waxy covering and habit of feeding in sheltered areas, they are difficult to control with pesticides, especially late in the season.