Papaya mealybug – a new invasive pest

About Papaya mealybug

Papaya mealybug is a new invasive pest that was first recorded in the Northern Territory in July 2023.  It has now also been widely observed in and around the greater Brisbane area.  It is an aggressive mealybug that attacks many plant species including papaw, frangipani and hibiscus.

High numbers of this pest will cause sticky secretions, sooty mould (a black fungal growth) and leaf drop.  Plant dieback and death are ultimately possible if unchecked.

Papaya mealybug on frangipani. (image N.T. Gov’t)

While this is a very nasty mealybug that found its way to Australia inadvertently we are fortunate on two counts.

  1. Australia is home to a native species of mealybug-feeding ladybird that is commonly known as ‘the mealybug destroyer’ or more precisely as Cryptolaemus montrouzieri (Cryptos for short).
  2. A tiny wasp parasitoid called Acerophagus papayae (with no common name) seems to have ‘piggybacked’ its way to Australia along with the mealybug.  This tiny wasp is proving to be a useful biological control agent of Papaya mealybug and has been deliberately released into several countries as this pest has made its way around the world.

The tiny beautiful parasitoid wasp Acerophagus papayae (Image N.T. Gov’t)

Control options for papaya mealybug

We know already from experience that while some soap and oil sprays may help reduce numbers of the mealybug, pesticides are not very effective and generally make the situation worse. This is because of their negative impact on beneficial insects.  Encouraging biological control agents to do the job for you is the more sustainable and rewarding approach.

A combined effort from ladybird beetles, parasitoid wasps, lacewings and hover flies will be the best strategy.

Our mealybug destroyer

Bugs for Bugs have been producing Cryptolaemus ladybird beetles now for more than 40 years.  These proven performers can be released to compliment your beneficial insect population in the battle against mealybug.

Cryptolaemus adult ladybird beetle – the ‘mealybug destroyer’ (Image Graphic Science)