Attention! Fall armyworm update

JOYCE WYLLIE

You may recall the fall armyworm (FAW) caterpillar profiled in The GB Weekly on 3 February this year, with a warning at the time to watch out for this new pest in our district. So how are we getting on?

Graeme McCleely, crop advisor at PGG Wrightson, reports that three farmers he works with found some caterpillars that were sent for identification, but were not FAW.

Alice Reilly, from the Rural Service Centre’s farm support team, reports that they did have “one confirmed case of FAW in maize in the Bay, which was reported to Ministry of Primary Industries (MPI) when found”. No control measures were taken, as maize has now all been harvested into sileage, but MPI are trying to get a picture of how widespread the pest is now. FAW was also discovered in maize crops on the West Coast. Now it is autumn, the risk has passed for this season. However, surveillance and monitoring will be ongoing, as established populations of this worm could be devastating to crops on farm and in gardens.

Nature Diary

It is autumn, the time of year when rats and mice come flocking indoors searching for shelter. This relationship between rodents and humans has endured for thousands of years.

Before human occupation, Aotearoa New Zealand had no rats. When Māori settled here, they brought with them kiore (the Pacific rat), an important source of protein. Kiore are the smallest of the three species of rat found in New Zealand. They suffered with the arrival of the Norway rat and the ship rat. The introduction of predators such as stoats and feral cats added to their decline. There are now few kiore populations left.

SUBMITTED BY CYNTHIA McCONVILLE

Our largest resident rat is the Norway rat, also known as the brown rat, arriving on whaling ships and those carrying early European settlers. Their most dramatic effects have been on islands where they have caused significant damage to seabird populations, eating eggs, chicks, and occasionally adult birds. Their distribution on the mainland is patchy, but they are a significant threat to ground nesting birds on beaches and in riverbeds. Norway rats can measure up to 50cm in length, including the tail, and weigh up to 500g. They tend to be found around waterways, wetlands, and in coastal areas. On arrival, Norway rats colonized the whole country, until they in turn were displaced by the arrival of ship rats.

The ship rat is the most abundant rat species in New Zealand. They are also the biggest threat to our wildlife. With an ability to scale almost any rough surface and jump up to 70cm, they are great climbers. Ship rats spend most of their time in trees hunting for nests to prey upon. There is no escape for our native birds when nesting. Ship rats will come indoors, often gaining access by climbing trees onto your roof, before finding a way inside. Smaller than the Norway rat, they weigh around 300g and have a body length, including the tail, of around 40cm. Next time you catch a rat you may want to take a closer look. Rattus rattus or Rattus norvegicus?