Melon fly

Zeugodacus cucurbitae

The melon fly feeds on a wide range of crops. It has spread to more than 40 countries, including Australia.

About the melon fly

The melon fly is native to central Asia but has spread across Asia and into Africa and Australia. Although melon fly has been found at our border a few times, it has not been detected inside New Zealand.

Global distribution of the melon fly

World map showing the distribution of the melon fly including Asia, parts of Africa, and Australia.

Why this is a problem for New Zealand

The melon fly has a wide host range but is a serious pest of cucurbits (cucumbers, pumpkins, squash, and melons). Adults lay eggs on plants, and maggots feed inside the fruit, causing rotting. Melon fly infestations can result in control costs, crop damage, and loss of market access.

Melon fly could survive in the warmer months in much of New Zealand. Populations may be able to establish in warmer parts of the country.

How it could get here

Melon fly could come to New Zealand inside fruit or vegetables infested with eggs or maggots.

Commercial shipments of host fruit and vegetables from countries where melon fly is known to be present must be treated to kill eggs and maggots. Passengers are screened at the border to prevent untreated fruit coming into the country.

Travellers must not bring any fruit or vegetables into New Zealand.

How to identify melon fly

Adult flies:

  • are 8 to 10mm long
  • are generally a golden to red-brown colour, sometimes with darker markings
  • have a dark stripe or T-shaped mark on their abdomen
  • have wings with a few dark bands or spots
  • may have a pointed "sting" or ovipositor.

Eggs are laid underneath the skin of the fruit. They hatch into small maggots which leave the fruit when mature, then pupate in soil.

 

Female melon fly on a leaf, showing the fly's markings and ovipositor
Adult female melon fly. (Image from NBAIR )

 

While melon fly maggots in a rotten fruit
Melon fly maggots infesting fruit. (Image from Entnemdept )

 

Dorsal view of an adult female melon fly
Dorsal view of an adult female melon fly. (MPI PHEL image)

 

Lateral view of an adult male melon fly
Lateral view of an adult male melon fly. (MPI PHEL image)

 

If you think you've found a melon fly

Catch it, photograph it, and call MPI's Exotic Pest and Disease Hotline on 0800 80 99 66


Note: This information is a summary of this pest's global distribution and potential impacts on New Zealand.

Last reviewed: