moth alert!

Falling fruit? A night-feeding moth may be the culprit, says PHIL DUDMAN

Ihad my first experience with this pest a few years ago. An early-cropping mandarin tree was dropping its fruit at an alarming rate, just weeks before they were ready to pick. On closer inspection, the fallen fruit had a soft sunken area around a small hole. I thought it might be fruit fly at first. The symptoms were similar, but there were no larvae in the fruit.

Turns out there was an outbreak of fruit-piercing moth (Eudocima phalonia) in the Northern Rivers region of

New South Wales at the time, and lots of gardeners and fruit growers were experiencing the same problem.

These moths are typically found in rainforest areas such as this, and they affect a range of fruits, including pawpaw, banana, mango, guava and, of course, citrus. The adult moth pierces the fruit with its proboscis (long tubular mouthpart), then sucks out the juice. The hole it leaves behind allows fruit-rotting fungi and bacteria to enter, which quickly spread and destroy the fruit.

With a wingspan of 10cm, they are fairly large moths, so you’d think they’d be hard to miss, sucking away on your prized fruits. However, they only come out to feed at night. I managed to spot one during a very early morning stroll around my patch. Its distinctive hind wings – orange with black markings – confirmed that I’d found the culprit.

Once you know you’ve got these moths in your garden, you’ll need to take immediate action if you want to protect your remaining crop. There are currently no home garden pesticide products (organic or otherwise) registered for the control of this pest on tropical fruits and citrus. The simplest and best way to guarantee a harvest is to cover your tree with a pest-exclusion net to keep the moths off the fruit. You can buy nets made for the job, and they’re good to have in your kit for controlling a range of fruit pests, including fruit fly. An alternative option is to cover the fruit individually with pest-exclusion bags, or even wrap them in newspaper, but it’s labour intensive.