A snowball in warm weather

Friend Christa sent me a photo of this colourful beastie – it’s a mealybug, in this case a snowball mealybug, Monophlebulus species. It was about the length of a thumbnail and found in disturbed earth in a garden.

Snowball mealybug, Monophlebulus species; photo by Christa Schwoebel

The body has a white, waxy layer, which is thought to control water loss and provide some disguise from the ladybird beetles and parasitic wasps that keep their population under control. The larvae are all-white and fluffy, but the adults (like the one in the photo) lose the wax layer and their colours are revealed.

There are about 200 species in Australia. They feed, using their straw-like mouthparts, on the sap of eucalypts and callistemons, and some are considered to be agricultural pests on commercial crops and in gardens.

Brisbaneinsects has good photos of both the shaggy larvae and the adults.

The Coffs Harbour Butterfly House also has good photos, including one being attended by an ant:

They are often attended by ants as they exude excess sugar syrup. The syrup is also deposited on the leaves, which then can become mouldy, reducing the light reaching the leaves. The mould, the loss of nutrients, and the injection of poisons into the plant all damage infected plants.

The ants will naturally protect their source of honeydew.

According to the WA Department of Agriculture:

Most mealybugs have a number of often overlapping generations per year. Their development is dependent on temperature. Temperatures of about 25°C and a high relative humidity are optimum for mealybugs and, like aphids, their populations reach peaks in spring and autumn.

Eggs can be laid singly or in clusters, and female long-tailed mealybugs have been recorded laying as many as 200 eggs in a lifetime. Egg clusters are usually embedded in a cocoon of waxy filaments.

After hatching, the juveniles (crawlers) search for suitable feeding sites in sheltered areas. Crawlers can be dispersed by wind and progress through five moults before reaching adulthood. For males, the last juvenile stage pupates in a silk cocoon, and emerges as a winged adult. Adult males do not feed, having no mouthparts — their sole purpose is to mate with females.

Here is a photo from friend Roselene (Beyond Nature) of what looks like the same beastie caught in the sap of a eucalypt tree.

Mealybug caught in eucalypt sap; photo by Roselene Cusack

I agree with Christa that, pest or not, “It looks truely weird.” Fortunately, I like “weird”.

This entry was posted in Animals on land, Insects and tagged . Bookmark the permalink.

4 Responses to A snowball in warm weather

  1. Roselene Cusack says:

    An interesting post, Joy. It’s answered a few questions, including the name of this bug.
    Weird is good.
    And that mealybug is weird.
    And now I need to trawl through my pics, to find the one of a mealybug caught in a sap flow.

  2. Kath says:

    That bug eats my plants! But I can still admire and respect the beauty of anything that shares this planet. Thanks for giving us a close up and now very personal view of this bug.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s