Horticulture: Could spiders help manage pests on New Zealand’s farms?

A female nursery web spider guards her web. Photo / RNZ

By Gianina Schwanecke of RNZ

Unravelling new information about spiders could be the key to unlocking productivity in the horticulture sector, according to scientists.

An article published in the New Zealand Journal of Ecology found there had been no research on the role spiders play in managing pests on horticultural farms here in Aotearoa.

Lead author and PhD candidate Nicola Sullivan, from Plant and Food Research, said spiders could help increase fruit production through predating pest insects, but more information was needed to attract spiders to these environments.

“Spiders are the most diverse and most abundant generalist predators in horticultural systems that have been seen overseas.”

She said they could play a “beneficial role” within horticulture, though she acknowledged it might be more difficult to rear them and introduce them to systems.

Part of this was that most of the NZ research to date has focused on spider numbers in specific farm ecosystems.

“We can look at ways that we can enhance and encourage them into those systems,” Sullivan said.

“So if we can understand what it is that the spiders like about a habitat, do they like the complex branch structure as they’ve found overseas, do they like native plantings.

“We can create those conditions within the productive system to encourage those spiders in and perform that ecosystem service of consuming pest insects.”

It’s been estimated that spiders consume up to 800 million tons of (mostly) bugs globally per year, and overseas studies have shown the positive impacts of this on horticultural farms.

“I think it’s an approach we should be looking at in Aotearoa NZ.”

Sullivan said more funding was needed to study how spiders can be used for more eco-friendly pest control practices in the horticultural sector.

- RNZ